bluuebunny/crossref_metadata_2025 huggingface dataset:
Further observations on the serological response to experimental Salmonella typhimurium in chickens measured by ELISA
Authors: Barrow P. A.
Published: May 2009

An indirect ELISA developed for the serological detection of Salmonella typhimurium in chickens using lipopolysaccharide as detecting antigen has been evaluated further in experimental infections. Following oral infection of 24-week-old laying hens with an invasive strain of S. typhimurium, high titres of specific circulating IgG were induced which were maintained for 20 weeks. Similar IgG titres were found in egg yolk. When 4-day-old chickens were infected high antibody titres persisted for 45 weeks. Chickens inoculated orally or intramuscularly with different numbers of S. typhimurium organisms showed graded serum IgG responses to LPS. The IgG titres in experimentally infected in-bred lines of chickens which showed greater genetic resistance to salmonella infection were significantly lower than those found in more susceptible lines. Oral and intramuscular infection with 18 different types of enterobacteria, including avian pathogenic E. coli, Citrobacter spp., Klebsiella spp., Proteus spp. and citrobacter-like organisms possessing some salmonella LPS (none possessed the 0–4 antigen) and flagella antigens, did not induce S. typhimurium LPS-specific IgG responses. Chickens infected orally with rough or non-flagellate mutants of S. typhimurium did not induce high titres of LPS or flagella-specific IgG respectively. Sera obtained from S. typhimurium-infected chickens showed much higher titres against S. typhimurium LPS than with those antigens from other serotypes, including S. enteritidis.
Biochemical and molecular characterization ofSalmonella entericaserovarberta, and comparison of methods for typing
Authors: Olsen J. E. , Brown D. J. , Baggesen D. L. , Bisgaard M.
Published: May 2009

Strains ofSalmonella entericaserovarberta(S. berta) from Denmark and seven other countries have been characterized with the aim of developing a rational typing strategy in connection with outbreak investigations.

Biotyping divided the strains into H2S-positive (90%) and H2S-negative (10%) biovars. Six percent of the strains were resistant to one or more antimicrobial agents. Eighty-eight percent of the strains carried plasmids and 52 different plasmid profiles were recognized. Six of the common plasmid sizes in these profiles were shown by restriction enzyme analyses to contain more than one plasmid species. More than 90% of the strains had the same ribotype with the restriction enzymesSmaI andEcoR I and the same whole cell protein profile. Outer membrane protein profiles and isoenzyme profiles were identical in allS. bertaanalysed.

Plasmid profiling in combination with restriction enzyme analysis of plasmids seemed to be the most rational typing strategy forS. berta. The results indicated thatS. bertastrains regardless of geographical source or host are possibly clonal in nature.
Numerical index of the discriminatory ability of biotyping and resistotyping for strains ofEscherichia coli
Authors: Crichton P. B. , Old D. C.
Published: May 2009

A discrimination index was applied to assess the value of biotyping and resistotyping, used alone or together, for the subspecific discrimination ofEscherichia coli.The index was high when 599 strains from a wide variety of sources were examined by full biotyping with 10 tests. Although the discrimination achieved was lower when a sub-collection of 333 strains was examined, that finding probably indicated that many of the latter strains were of urinary origin and represented a limited number of uropathogenic clones. Combined biotyping and resistotyping provided a higher level of strain discrimination than either method used on its own. Results suggest that these typing methods may be used with confidence for the discrimination of strains ofE. coli.
Serology and anthrax in humans, livestock and Etosha National Park wildlife
Authors: Turnbull P. C. B. , Doganay M. , Lindeque P. M. , Aygen B. , McLaughlin J.
Published: May 2009

Results are presented from a number of epidemiological studies using enzyme immunoassays (EIA) based on the purified anthrax toxin antigens, protective antigen, lethal factor and oedema factor. Studies on sera from a group of 62 human anthrax patients in Turkey and from cattle in Britain following two unrelated outbreaks of anthrax show that EIA using protective antigen can be a useful diagnostic aid and will detect subclinical infections in appropriate circumstances. A serological survey on wildlife in the Etosha National Park, Namibia, where anthrax is endemic, showed that naturally acquired anthrax-specific antibodies are rare in herbivores but common in carnivores; in carnivores, titres appear to reflect the prevalence of anthrax in their ranges. Problems, as yet unresolved, were encountered in studies on sera from pigs following an outbreak of anthrax on a farm in Wales.

Clinical details, including treatment, of the human and one of the bovine outbreaks are summarized and discussed in relation to the serological findings.
Prevalence of serotypes ofXanthomonas maltophiliafrom world-wide sources
Authors: Schable B. , Rhoden D. L. , Jarvis W. R. , Miller J. M.
Published: May 2009

Since its development in 1988, a serologic typing scheme forXanthomonas maltophilia, based on 31 O antigens, has been successfully used to serotype isolates involved in nosocomial outbreaks in the United States. To determine if this serotyping scheme would be useful in typingX. maltophiliaisolates from worldwide sources, we obtained additional isolates from 10 countries; of 900 isolates tested, 795 (88·3%) were typable. In order of predominance, the three most common serotypes were 10, 3 and 19. These three serotypes were most frequently associated with respiratory and blood isolates. This serotyping system is useful as an epidemiologic screening method for universal typing of outbreaks ofX. maltophiliainfections.
Legionellae isolated from clinical and environmental samples in Spain (1983–90): monoclonal typing ofLegionella pneumophilaserogroup 1 isolates
Authors: Pelaz C. , García L. , Martín-Bourgon C.
Published: May 2009

Legionella isolates recovered in 21 different Spanish provinces over 8 years from both clinical (67 isolates) and environmental (181) samples, mostly from case-associated buildings, are described: 92·5% of clinical isolates wereL. pneumophilaserogroup 1 (SGI), only five isolates belonging to other species or serogroups: twoL. pneumophilaSG6, two SG8 and oneL. bozemaniiSG1 not clearly related with clinical infection.

L. pneumophilaSG1 accounted for 53·6% of isolates from the environment, followed by SG8 (27·6%). SG3 (9·4%) and SG6 (7·2%). Three isolates were labelled as SG8/10.

Subtyping ofL. pneumophilaSG1 by the standardized panel of monoclonal antibodies revealed 90·3% of clinical and 78·3% of environmental isolates as belonging to Pontiac subgroup. Pontiac isolates were further divided into 55·3% Philadelphia 1 or Allentown 1, 21·9% Benidorm 030E and 20·4% Knoxville 1.

Characterization of samples from four outbreaks in which both clinical and environmental isolates had been recovered permitted the recognition of three Philadelphia 1 or Allentown 1 and one Knoxville 1 strains as the aetiological agents.
Analysis of some virulence factors ofVibrio vulnificusisolated from Rio de Janeiro, Brazil
Authors: Rodrigues D. P. , Ribeiro R. V. , Hofer E.
Published: May 2009

Twenty strains ofV. vulnificusisolated from the environment were investigated for characteristics related to their infectivity such as colonial morphology, enzymatic activity and animal assays. The presence of DNase, chitinase, amylase, lecithinase and gelatinase was observed in 100% of the strains, haemolytic activity was absent, and variable results were obtained in elastase, collagenase and chondroitinase. In the animal assays, 70% of the strains were lethal to adult mice, while 45% caused fluid accumulation in suckling mice. Although all strains had opaque colonies, only 3 of the 20 had the three enzymes elastase, collagenase and gelatinase, and only one of these was virulent in animal assays.
Influenza deaths in Leicestershire during the 1989–90 epidemic: implications for prevention
Authors: Nguyen-Van-Tam J. S. , Nicholson K. G.
Published: May 2009

There is an association between excess winter mortality and epidemics of influenza and it has been suggested that annual influenza vaccination should be offered to all over 65 years old as in the United States. This paper identifies the number of people dying from influenza in Leicestershire UK during the 1989–90 epidemic and the factors associated with a fatal outcome. The findings show that deaths attributed to influenza occur predominantly in very elderly people with underlying ill-health. The risk of influenzal death is greater in residential patients and increases substantially with the number of underlying medical conditions. The estimated death rates in vaccinated and non-vaccinated groups were not significantly different, but there were trends towards protection in both residential and non-residential groups. Influenza vaccine is not reaching the principal target groups and improved methods of influenza control are required.
Subacute sclerosing panencephalitis (SSPE) in Papua New Guinea: a high incidence in young children
Authors: Lucas K. M. , Sanders R. C. , Rongap A. , Rongap T. , Pinai S. , Alpers M. P.
Published: May 2009

Eighty-seven cases of subacute sclerosing panencephalitis (SSPE) were diagnosed from September 1988 to April 1991 in Papua New Guinea (PNG), by demonstration of high-titre measles-specific antibodies in cerebrospinal fluid (CSF). For 1990 the annual incidence of SSPE, for the study provinces, was calculated to be 56 cases per million under 20 years of age and it is expected that this figure will be higher in 1991. The mean age of presentation was 4.9 years, with a male to female ratio of 1.8:1. An elevation in the ratio of immunoglobulin G as a percentage of total protein in CSF and an increase in the CSF:serum immunoglobulin G ratio was shown in SSPE patients. The dramatic appearance and high frequency of the disease in PNG might relate to the early age of measles infection encountered in children in this country.
Molecular epidemiology of shigella infections in Israel
Authors: Yavzori M. , Cohen D. , Bercovier H.
Published: May 2009

The DNAs ofShigella sonneiorShigella dysenteriaetype 1 strains isolated in outbrealis of shigellosis or in sporadic cases were analysed by restriction fragment length polymorphism (RFLP). Southern blots of the DNAs of 36S. sonneiisolates digested by 8 restriction enzymes were hybridized with anEscherichia colirRNA probe. TheS. sonneistrains were unexpectedly diverse in their RFLP. Antibiotypes of the same isolates showed clusters of strains corresponding to the various outbreaks. On the other hand, RFLP analysis suggested concomitant multiple sources of infection rather than a common source and thereby introduced a new insight in the epidemiology of shigellosis. RFLP was also used to traceS. dysenteriaetype 1 transmission in a recent cluster of clinical cases. Although antibiotic resistance patterns indicated the presence of more than one strain, RFLP analysis showed that the six isolates were identical clones and suggested the loss of an R episome after one person-to-person passage.
An investigation into an outbreak of Salmonella enteritidis phagetype 4 infection and the consumption of custard slices and trifles
Authors: Barnes G. H. , Edwards A. T.
Published: May 2009

Epidemiological investigation into an outbreak of food poisoning in 17 patients caused by Salmonella enteritidis phage-type 4 demonstrated a highly significant association with consumption of custard, retailed in custard slices and trifles from a bakery on one day. The bakery had changed their recipe for custard 2 weeks earlier to include fresh shell eggs and had not followed earlier national advice on cooking eggs for human consumption. The case-control study supports earlier work associating Salmonella enteritidis phage-type 4 infection with consumption of uncooked or lightly cooked shell eggs.
The identification of Salmonella enteritidis-infected poultry flocks associated with an outbreak of human salmonellosis
Authors: Giessen A. W. van de , Dufrenne J. B. , Ritmeester W. S. , Berkers P. A. T. A. , Leeuwen W. J. van , Notermans S. H. W.
Published: May 2009

In the summer of 1991 a human outbreak of Salmonella enteritidis infection occurred following a barbecue in which about 100 persons were involved. Eggs, supplied by one or more of 10 different layer farms, were the most probable source of the infection. To identify the S. enteritidis-positive flocks, an immunoassay was used to detect salmonella serogroup D-specific antibodies in the yolk of hens eggs. Antibody titres in the eggs from two layer farms, farm A and B, clearly exceeded the titres found in randomly collected eggs. Further investigations on farm A and B yielded high antibody titres in the eggs from flocks A1, A2 and B2, and low titres in the eggs from flock B1. S. enteritidis was isolated from the faecal samples of flocks A1, A2 and B2, whereas no salmonella was detected in the faecal samples of flock B1. The flocks present on both farms originated from the same breeder flock.
Transferable high-level trimethoprim resistance among isolates ofEscherichia colifrom urinary tract infections in Ontario, Canada
Authors: Harnett N.
Published: May 2009

Of 1171 isolates ofEscherichia coliisolated from urine samples at the Public Health Laboratory, Toronto, Ontario, Canada, between May 1990 and December 1991, 120 (10·3%) were resistant to trimethoprim (TMP), cotrimoxazole (TMP/SMX), sulfamethoxazole (SMX) and other antimicrobial agents; 110 of the 120 isolates (91·7%) were resistant to four or more agents. The majority of resistant isolates (91·7%) exhibited high-level resistance (MIC > 1000 mg/L) to TMP. The MIC of TMP/SMX for all 120 isolates was > 2·0/38·0 mg/L and for SMX > 1024 mg/L. High-level resistances were also present among the β-lactam antimicrobials with MICs ranging from 16- > 256 mg/L. Forty-three of 120 TMP-resistant (35·8%) isolates conjugally transferred TMP-resistance toE. coliK-12. Co-transfer of several other resistances was observed. SMX cotransferred from 86% of the 43 donors and β-lactams together with SMX cotransferred from 70%. Nalidixic acid resistance was present among 22 (18·3%) of the 120 resistant isolates, however, nalidixic acid resistance was not transferred toE. coliK-12.
Epidemiology of typhoid fever in Singapore
Authors: Yew F. S. , Goh K. T. , Lim Y. S.
Published: May 2009

A total of 1452 cases of typhoid fever was notified in Singapore from 1980–9. The morbidity rates of indigenous cases showed a steady decline from 5.9 per 100000 population in 1980 to 1.2 per 100000 population in 1989. The mean case fatality was 0.8%. Children, adolescents and young adults were most susceptible to typhoid fever. There was no significant difference in morbidity rates between the major ethnic groups. The vast majority of indigenous cases were sporadic while outbreaks accounted for almost one third of them. Food was the main vehicle of transmission. The commonest indigenous phage types were B1, D1 and A. Antimicrobial resistance was infrequently seen. The proportion of imported cases rose from 32% in 1980 to 72% in 1989. Almost half (48.5%) of all imported cases were local residents who contracted typhoid fever while travelling in endemic countries. As imported cases assume greater importance in the epidemiology of typhoid fever in Singapore, further drop in typhoid fever incidence would require reduction of travel-related cases through greater awareness of food hygiene and effective vaccination.
Outbreak of Legionnaires' disease at University Hospital, Nottingham. Epidemiology, microbiology and control
Authors: Colville A. , Crowley J. , Dearden D. , Slack R. C. B. , Lee J. V.
Published: May 2009

Twelve patients in a large teaching hospital contracted Legionnaires' disease over a period of 11 months. The source was a domestic hot water system in one of the hospital blocks, which was run at a temperature of 43 °C. Five different subtypes ofLegionella pneumophilaserogroup 1 have been isolated from water in different parts of the hospital, over a period of time. Only one subtype, Benidorm RFLP 14, was implicated in disease. Circumstantial evidence suggested that the outbreak may have been due to recent colonization of the hot water system with a virulent strain ofLegionella pneumophila. The outbreak was controlled by raising the hot water temperature to 60 °C, but careful surveillance uncovered two further cases in the following 30 months. Persistent low numbers ofLegionella pneumophilawere isolated from the domestic hot water of wards where Legionnaires' disease had been contracted, until an electrolytic unit was installed releasing silver and copper ions into this supply.
Phage typing of Vero cytotoxin-producingEscherichia coliO 157 isolated in the United Kingdom: 1989–91
Authors: Frost J. A. , Cheasty T. , Thomas A. , Rowe B.
Published: May 2009

Between 1989 and 1991 a total of 1092 Vero cytotoxin-producingEscherichia coliO 157 isolated in the United Kingdom were phage typed in the Laboratory of Enteric Pathogens (LEP). Twenty-three phage types was identified, the most frequent being types 2 (36·1%), 49 (29·6%), 1 (10·3%) and 4 (8·9%). Although isolations of O 157 VTEC have increased each year from 1 in 1982 to 532 in 1991, the predominant phage types have remained unchanged although the proportion of strains belonging to types 2 and 49 has increased. O 157 VTEC from 17 outbreaks were phage typed during this period with phage type 49 predominating (7 of 17 outbreaks).
Enterotoxins and toxic-shock syndrome toxin-1 in non-enteric staphylococcal disease
Authors: Marples R. R. , Wieneke A. A.
Published: May 2009

Over the 7 years 1985–91, 997 strains of Staphylococcus aureus from 962 patients with diseases other than food poisoning have been tested for the production of enterotoxins and toxic shock syndrome toxin-1 (TSST-1) and phage typed. In all, 128 cases could be classified as confirmed or probable toxic shock syndrome (TSS) but a further 199 cases were classified as possible or unconfirmed TSS. In 219 cases, an alternative diagnosis could be supported and 45 cases were classified as sudden infant death syndrome. In 371 cases, insufficient information for classification was available.

Strains of phage group I producing TSST-1 were associated with menstrual TSS. Many menstrual TSS cases were aged less than 20 and were using non-introducer tampons.

When all strains were reviewed, strong associations were observed between TSST-1 production and phage group I strains, enterotoxin B production and group V strains, enterotoxin C and phage-type 95 strains and between enterotoxin A without TSST-1 and phage group III strains.
Epidemiology ofSalmonella typhimurium: ribosomal DNA analysis of strains from human and animal sources
Authors: Nastasi A. , Mammina C. , Villafrate M. R.
Published: May 2009

Salmonella typhimuriumis the most frequently identified serovar ofSalmonellain Italy. This serovar is characterized by the widespread dissemination among human and non-human sources of phenotypically and genetically well-differentiated clones.

In this study 457 strains ofS. typhimuriumisolated in Italy in the years 1982–91 from human and animal sources were submitted to characterization by the rDNA fingerprinting technique. Application of this typing method, after digestion of chromosomal DNA withHincII endonuclease, confirmed the greatest genetic differentiation of clones ofS. typhimurium, allowing reliable identification of 45 rDNA patterns linked into 9 major clusters. rDNA pattern clusters or ribotypes specific to man were not recognized, whereas some rDNA patterns were characteristically related to ducks, pigeons and pet birds. The ribotyping results for isolates from animal hosts suggest that pig and cattle are the main source of human infection.
Dose-response in an outbreak of non-bacterial food poisoning traced to a mixed seafood cocktail
Authors: Gray S. F. , Evans M. R.
Published: May 2009

An outbreak of non-bacterial food poisoning presumed due to small round, structured viruses (SRSV) occurred at a national conference.

A detailed postal survey of all conference attenders was carried out to ascertain the cause of the outbreak and 355 questionnaires were returned.

Univariate analysis showed that mussels in the seafood cocktail were the likely vehicle of infection. A dose–response relationship between the amount of seafood cocktail consumed and the risk of illness was demonstrated. Dose–response has not previously been documented in a food-borne outbreak due to small round structured virus.

Detailed quantitative food histories can be useful in eliciting dose-response relationships and may be crucial in establishing the vehicle of infection when investigating food poisoning following consumption of a set-menu meal. Their use should be considered in other outbreak situations.
Arcobacter cryaerophilusand thermophilic campylobacters in a sewage treatment plant in Italy: two secondary treatments compared
Authors: Stampi S , Varoli O , Zanetti F , De Luca G
Published: May 2009

Microaerophilic organisms were monitored in sewage effluent undergoing two secondary treatments: air and oxygen-activated sludge. The mean numbers ofArcobacter cryaerophilusand thermophilic campylobacters detected in incoming sewage were 5639/100 ml and 1720/100 ml respectively.

Secondary treatment in air tanks reduced the population ofA. cryaerophilusby 97.1% and of thermophilic campylobacters by 99.08%, whereas treatment in oxygen tanks reduced the bacteria 97.8% and 99.63% respectively, showing that oxygen-activated sludge treatment was more effective. Subsequent tertiary treatment with 2 p.p.m. chlorine dioxide evidenced the removal ofA. cryaerophilusto 99.9% and eliminated thermophilic campylobacters.

Campylobacter jejuniandC. coliconstituted 54.1% and 45.9% of 74 thermophilic campylobacter strains isolated. In air-activated sludge effluentC. jejuniwas found more often, thus appearing more sensitive to oxygen.

The most probable number assay used for detection of campylobacters, blood medium for enrichment and blood-free medium for plating, also appeared to be fit forA. cryaerophilus, the high density of which in urban sewage may be due to inflows from slaughterhouses.
Epidemiology ofStaphylococcus aureusin patients with cystic fibrosis
Authors: Branger C. , Fournier J. M. , Loulergue J. , Bouvet A. , Goullet Ph. , Boutonnier A. , De Gialluly C. , Couetdic G. , Chomarat M. , Jaffar-Banjee M. C. , Mariani P.
Published: May 2009

Seven hundred and thirty-four isolates ofStaphylococcus aureus, recovered from the sputum of 238 cystic fibrosis patients in six French hospitals, were characterized by esterase electrophoretic typing, capsular polysaccharide serotyping and phage typing and tested against 14 antibiotics for sensitivity. Thirty-four esterase electrophoretic types were found with a genotypic diversity coefficient of 0·91. Five hundred and forty-eight (78·7%) isolates produced capsular polysaccharide and 350 (50·3%) were type 8. Four hundred and sixty isolates (66·6%) were phage typable and 202 (28·2%) were lysed by group III bacteriophages. No esterase electrophoretic type, capsular type or phage type was specific to cystic fibrosis. Isolates belonged to a wide range of types, similar to strains acquired outside hospitals. Eighty-five patients had three or more consecutive isolates over at least 6 months. The ability ofS. aureusto persist for long periods of time has been demonstrated in 73% of them. Methicillin-resistance was encountered among 73 strains (9·8%) which were also multiresistant. Two hundred and eighty-nine (39·9%) strains were sensitive to all antibiotics tested except to penicillin. Pristinamycin and co-trimoxazole were the most effective antibiotics. These results could contribute to the elaboration of a rational approach to the prophylaxis and therapy of respiratory staphylococcal infections in cystic fibrosis patients.
Clonal study of enterotoxin-B producing strains ofStaphylococcus aureus
Authors: Renaud F. , Bornstein N. , Meugnier H. , Forey F. , Bes M. , Fleurette J.
Published: May 2009

Sixty-nineStaphylococcus aureusstrains. 39 of which produced staphylococcal enterotoxin B (SEB + ) and 14 of which were associated with toxic shock (TS + ), were studied using the following markers: serotyping, phage typing, antibiotyping. ribotyping, zymotyping and pulsed-field electrophoresis typing. Analysis of the results showed that the enterotoxin B producing strains were derived from at least three clones: the first two consisted of methicillin-susceptible strains, while the third included the methicillin-resistant (MRSA) strains. TS+ strains of non-genital origin appeared to be distributed between the three clones, with no specific characters.
Risk factors for giardiasis: a case-control study in Avon and Somerset
Authors: Gray S. F. , Gunnell D. J. , Peters T. J
Published: May 2009

Giardia lamblia is a common and increasing cause of gastrointestinal illness in the UK. We report a case-control study that examined risk factors for giardiasis. Patients with giardiasis were identified from reports to the Consultants in Communicable Disease in1 Avon and Somerset, and age-sex matched controls were obtained from their general practitioners' lists. Details of travel history, water consumption and recreational water use were collected by postal questionnaire. Over the period July 1992 to May 1993, 74 cases and 108 matched controls were obtained. The data were analysed using conditional logistic regression. Swimming appeared to be an independent risk factor for giardiasis (odds ratio 2·4, 95% CI 1·0 to 6·1, P = 0·050). Travel (P = 0·001), particularly to developing countries, and type of travel (P = 0·004) - that is, camping, caravanning or staying in holiday chalets - were also observed to be significant risk factors. Other recreational water use and drinking potentially contaminated water were found to be not statistically significant after adjustment for other factors.
Age-specific antibody prevalence to hepatitis A in England: implications for disease control
Authors: Gay N. J. , Morgan-Capner P. , Wright J. , Farrington C. P. , Miller E.
Published: May 2009

Sera from an age-stratified sample of 7196 individuals, submitted for diagnostic purposes to four public health laboratories in England in 1986/7, were tested for hepatitis A antibody. The serological profiles, which showed marked regional differences, were consistent with declining incidence in the past. The decline in the incidence of hepatitis A has resulted in an increase in susceptibility in adults. This has three main consequences: an increase in the average age of infection may be leading to an increase in morbidity; normal immunoglobulin may become less protective against hepatitis A; the risk of transmission through blood products contaminated by viraemic blood donors may rise.

Current average annual incidence in 5–14-year olds was estimated to vary between regions from 0·5–1·9%. This supports the view that, in the absence of a vaccination programme, hepatitis A will remain endemic unless there are further improvements in living conditions and standards of hygiene. A vaccine giving long-lasting protection could eliminate hepatitis A transmission with modest coverage at a young age. Targeting childhood vaccination on economically deprived areas or using vaccine to control outbreaks might be more effective policies.
Survey of fox trappers in northern Alaska for rabies antibody
Authors: Follmann E. H. , Ritter D. G. , Beller M.
Published: May 2009

The purpose of this research was to determine whether trappers in northern Alaska acquired immunity to rabies virus from non-bite exposures while trapping and skinning arctic foxes (Alopex lagopus). In coastal Alaska recurring epizootics presumably provide trappers ample opportunity for contact with rabid animals. Serum neutralization analyses of blood samples collected from 26 individuals were conducted. All but three had negative rabies neutralizing antibody levels (< 0·05 I.U./ml). Two of these had previously received rabies vaccine but one individual who had trapped for about 47 years with an estimated harvest of over 3000 foxes and who had never received pre- or post-exposure rabies vaccination had a rabies serum neutralizing antibody concentration of 2·30 I.U./ml. This represents the first report of an unvaccinated person acquiring rabies virus antibody with a titre above the 0·5 I.U./ml level considered acceptable by the World Health Organization.
Flagellin gene polymorphism analysis ofCampylobacter jejuniinfecting man and other hosts and comparison with biotyping and somatic antigen serotyping
Authors: Owen R. J. , Fitzgerald C. , Sutherland K. , Borman P.
Published: May 2009

Flagellin gene sequence polymorphisms were used to discriminate amongst 77 strains ofCampylobacter jejunifrom sporadic and outbreak-associated human enteric infections, and from chickens, sheep and calves. The results were assessed in relation to Lior biotyping and serotyping (Penner somatic antigens). Eight DNA PCR-RFLP patterns (genotypes) were identified by analysis ofHinfI fragment length polymorphisms in flagellin gene (flaA) polymerase chain reaction (PCR) products. One genotype (F-l) was a feature of 55% of strains. Strains within the genotypes were heterogeneous with respect to somatic antigens with 12 serogroups represented amongst theC. jejuniisolates offlaA type F-l. Serogroups Pen 1. 2 and 23 were the commonest (45%) amongst the 20 different serogroups represented. Several unique clusters of isolates with diverse biotypes were defined, and one cluster (F-7/Pen 23) contained epidemiologically implicated outbreak strains as well as sheep and calf isolates. We conclude thatHinfIflaA typing is reproducible and offers high typability, and its combination with serogrouping provides a novel approach to characterizing isolates ofC. jejuniwith improved discrimination.
Toxin production, adherence and protein expression by clinicalAeromonasspp. isolates in broth and human pooled ileostomy fluid
Authors: Wilcox M. H. , Cook A. , Geary I. , Eley A.
Published: May 2009

The physiological behaviour of clinicalAeromonasspp. isolates was compared following culture in a conventional broth and human pooled ileostomy fluid (PIF). Protein expression was markedly affected by the growth medium, with an overall reduction in whole cell proteins in bacteria grown in ileostomy fluid. In addition, novel outer membrane proteins were produced in PIF but not in broth. The majority ofA. hydrophilaandA. sobriaisolates produced toxin in both broth and PIF. whereas no cytotoxin positiveA. caviaewere found. Toxin titres were at least two doubling dilutions higher in 40% and 21% ofA. hydrophilaandA. sobriaisolates, respectively, following culture in brain heart infusion broth compared with PIF. Bacterial adherence to Vero and A-549 cells was significantly more common inA. hydrophila(53%) andA. sobria(64%) than inA. caviae(15%) (P < 0·01). We observed increased adherence by 6 Aeromonas strains previously classified as adherence-positive, but not by 6 non-adherers, in PIF compared with brain heart infusion broth. The influence of growth medium on the expression of potential virulence determinants byAeromonasspp. provides a rationale for the use of human ileostomy fluid in futurein vitrostudies, in order to simulate the nutrient conditions foundin vivo.
Hereditary deficiency of the seventh component of complement and recurrent meningococcal infection: investigations of an Irish family using a novel haemolytic screening assay for complement activity and C7 M/N allotyping
Authors: Egan L. J. , Orren A. , Doherty J. , Würzner R. , McCarthy C. F.
Published: May 2009

Terminal complement component deficiency predisposes to meningococcal infection and is inherited in an autosomal co-dominant manner. An Irish family is described, in which 2 of 3 brothers had recurrent meningococcal infection. A novel screening assay was used to investigate for terminal complement deficiency and the 2 affected brothers were found to be completely deficient in the seventh component of complement (C7). Enzyme-linked immunosorbent assay for C7 revealed lower than normal levels in the remaining brother and parents. C7 M/N protein polymorphism allotyping, used to investigate the segregation of the C7 deficiency genes, showed that the apparently complement sufficient brother was heterozygous C7 deficient and a carrier of one of the deficiency genes. Complement screening should be carried out in any individual suffering recurrent meningococcal infection or infection with an uncommon meningococcal serogroup. Identification of complement deficient patients allows the implementation of strategies to prevent recurrent infection.
Contamination of hospital linen by Bacillus cereus
Authors: Barrie D. , Hoffman P. N. , Wilson J. A. , Kramer J. M.
Published: May 2009

An investigation into two cases of post-operative Bacillus cereus meningitis revealed that hospital linen laundered by a batch continuous washing machine was heavily contaminated by B. cereus spores. The washing machine, detergents, other chemical additives and the water supply were eliminated as the source of contamination.

It was found that the linen introduced into the washing machine had a high B. cereus spore content and that this was still present after the wash process. The spores were not killed by either the heat disinfection stage of the wash or the addition of chemical disinfectants and were not removed by the dilution in the process.

The multiplication of B. cereus was thought to have occurred on used, damp linen stored in plastic bags, particularly when ambient temperatures were high. An increase in the water flow through the washing machine was the only measure associated with a decrease in B. cereus on laundered linen.
Successful control of a school based measles outbreak by immunization
Authors: Lyons R. A. , Jones H. I. , Salmon R. L.
Published: May 2009

In an outbreak of measles in North Wales centred on a secondary school in 1991, 74 cases occurred over a period of 51 days. Before the outbreak started, 27 % pupils did not have a history of measles or immunization and were considered susceptible. Active case rinding and identification and vaccination of susceptible contacts commenced after the fourth generation of cases and further reduced the pool of susceptible schoolchildren from 17%, at the onset of the vaccination campaign, to 8%. A fifth generation of cases did not occur. Delays in diagnosis (mean 2·8 days) and notification (mean 6·1 days) hampered control. There was no evidence of primary vaccine failure (observed vaccine efficacy 97%). Sixty-nine (93%) cases were considered preventable. Reasons for the apparent success of the intervention are discussed.
Molecular characterization and antibiotic susceptibility ofVibrio choleraenon-O1
Authors: Dalsgaard A. , Serichantalergs O. , Pitarangsi C. , Echeverria P.
Published: May 2009

A collection of 64 clinical and environmentalVibrio choleraenon-O1 strains isolated in Asia and Peru were characterized by molecular methods and antibiotic susceptibility testing. All strains were resistant to at least 1 and 80% were resistant to two or more antibiotics. Several strains showed multiple antibiotic resistance (≥ three antibiotics). Plasmids most often of low molecular weight were found in 21/64 (33%) strains. The presence of plasmids did not correlate with antibiotic resistance or influence ribotype patterns. In colony hybridization studies 63/64 (98%)V. choleraenon-O1 strains were cholera toxin negative, whereas only strains recovered from patients were heat-stable enterotoxin positive. Forty-sevenBglI ribotypes were observed. No correlation was shown between ribotype and toxin gene status. Ribotype similarity was compared by cluster analysis and two main groups of 13 and 34 ribotypes was found. Ribotyping is apparently a useful epidemiological tool in investigations ofV. choleraenon-O1 infections.
Meningococcal meningitis and carriage in western Zaire: A hypoendemic zone related to climate?
Authors: Cheesbrough J. S. , Morse A. P. , Green S. D. R.
Published: May 2009

An analysis of bacteria recovered from cerebrospinal fluid over a 16-year period at a rural hospital in western Zaire showed that Neisseria meningitidis accounted for only five (2·2%) isolates. A survey of naso-pharyngeal colonisation with N. meningitidis in 378 healthy children was undertaken to distinguish whether this low frequency was due to lack of carriage or, by inference, lack of the co-factors necessary to permit invasive disease. N. meningitidis was recovered from only three (0·78%) of the children. All isolates were non-typable strains of low pathogenicity.

A review of studies examining the aetiology of bacterial meningitis and the geographical location of epidemics of meningococcal meningitis in and around Zaire reveals a ‘hypoendemic zone’, the limits of which correlate well with the area in which mean absolute humidity remains above 10 g m−3 of air throughout the year. Continuous high absolute humidity appears to reduce the transmission of meningococci.
The occurrence of Mycobacterium bovis infection in cattle in and around an area subject to extensive badger (Meles meles) control
Authors: Clifton-Hadley R. S. , Wilesmith J. W. , Richards M. S. , Upton P. , Johnston S.
Published: May 2009

The occurrence of Mycobacterium bovis infection in cattle herds during the period 1966–92 in two geographically related areas in South-West England is compared. In one area comprising 104 km2 all badgers were systematically destroyed from 1975–81, after which recolonization was allowed; in the other, comprising 116 km2, small scale, statutory badger removal operations were undertaken from 1975 onwards where specific herds were detected with M. bovis infection. In the area with total clearance, no further incidents with M. bovis isolation occurred from 1982–92. Survival analysis and proportional hazards regression indicated that the risk of herds being identified with infection was less once badgers had been cleared from their neighbourhood, whereas it was greater in herds with 50 or more animals, and once cattle in a herd had responded positively to the tuberculin skin test, even though infection with M. bovis was not confirmed subsequently. The study provides further evidence that badgers represent an important reservoir of M. bovis infection for cattle and that badger control is effective in reducing incidents of cattle infection with M. bovis if action is thorough and recolonization is prevented.
Sporadic isolates ofEscherichia coliO157.H7 investigated by pyrolysis mass spectrometry
Authors: Freeman R. , Sisson P. R. , Jenkins D. R. , Ward A. C. , Lightfoot N. F. , O'Brien S. J.
Published: May 2009

Thirty-six encoded isolates ofEscherichia coli, 32 of which were of serotype O157. were examined by pyrolysis mass spectrometry (PyMS). Thirty-one of the serotype O157 isolates possessed the flagellar antigen H7 and produced Verocytotoxin (VT). the other isolate serotyped as H45 and was non-toxigenic. Eighteen of the VT-producingE. coli(VTEC) isolates were from sporadic disease in residents of the Northern Region. Standard principal component (PC) and canonical variate (CV) analysis of the data distinguished only the four non-O157 isolates from the remainder which were indistinguishable by this approach. A similarity matrix based on differences between individual CV means distinguished a further ten isolates. The matrix correctly clustered 2 pairs of isolates from siblings and 4 isolates from an affected family. A further 5 clusters of 3 or more isolates and 6 pairs of isolates were defined. These groupings proved to be homogenous for toxin phenotype but occasionally entrained isolates of dissimilar phage type. However, in general, PyMS-derived clustering of apparently sporadic isolates accorded with geographical locations as determined by postcode. PyMS, which is a quick and high volume capacity phenotypic technique. may be a useful addition to existing methods in the investigation of the epidemiology of sporadic VTEC disease.
Usefulness of the DNA-fingerprinting pattern and the multilocus enzyme electrophoresis profile in the assessment of outbreaks of meningococcal disease
Authors: Weis N. , Lind I.
Published: May 2009

The objective of the study was to assess whether genotypic characterization by means of DNA-fingerprinting pattern (DFP) and multilocus enzyme electrophoresis (MEE) profile as compared to phenotypic characterization would improve the differentiation ofNeisseria meningitidisstrains associated with outbreaks from strains associated with sporadic cases of meningococcal disease. In addition, the differentiation of serogroup C carrier strains from those associated with an outbreak of serogroup C meningococcal disease was investigated.

A total of 118N. meningitidisstrains were available for the study: 59 from patients involved in outbreaks of meningococcal disease (2 serogroup B and 2 serogroup C), 37 from patients considered to be sporadic cases and 22 serogroup C carrier strains.

Among the 59 strains from patients involved in outbreaks the 4 strains isolated from the patient registered as the first in each outbreak were designated the index strains. Among the remaining 55 outbreak strains 52 were either DFP-identical or DFP-indistinguishable when compared with the one relevant out of the 4 index strains. This was only the case for 17 of the 37 strains isolated from sporadic cases caused by the same serogroup of meningococci during the outbreak periods, and 5 of the 22 meningococcal strains isolated from healthy carriers. Among the 56 (52 + 4) DFP-identical or DFP-indistinguishable outbreak strains 5 different electrophoretic types were identified by MEE.

Among 59 assumed outbreak strains a total of 4 were identified as genotypically distinct. Among the 37 mainly DFP-indistinguishable or DFP-different strains from sporadic cases 17 different ETs were identified, and among the 22 mainly DFP-different carrier strains 13 different ETs were identified. Two strains among those selected from sporadic cases were identical to the outbreak strain. None of the local serogroup C carrier strains isolated during the outbreak of serogroup C disease were identical to the outbreak strain.

Both DNA-fingerprinting and MEE improved the differentiation of meningococci when compared with phenotypic characterization. The results indicate that tracing a virulent strain within an open group of contacts is irrelevant.
Specific detection ofSalmonella entericaserotype Enteritidis using the polymerase chain reaction
Authors: Lampel K. A. , Keasler S. P. , Hanes D. E.
Published: May 2009

An assay was developed for the specific detection ofSalmonella entericaserotype Enteritidis, using a novel application of the polymerase chain reaction (PCR). This PCR assay is based on the mismatch amplification mutation assay, an allele-specific reaction, and can discriminate Enteritidis from all other salmonella. PCR primers were selected to amplify a 351-base pair (bp) DNA fragment from the salmonella plasmid virulence A (spvA) gene of Enteritidis. A single base difference at position 272 is present between the nucleotide sequence of thespvAgene of Enteritidis and other salmonellae. The downstream PCR primer, that encompasses position 272 of the EnteritidisspvAgene, was designed to contain a single base mismatch at the penultimate position, resulting in a l-base mismatch with Enteritidis and a 2-base mismatch with other salmonellae that harbour the virulence plasmid. The upstream primer was completely homologous with the region immediately 5′ to thespvAgene. When these primers were used and the annealing and extension reactions were performed at the same temperature, the PCR assay was specific for Enteritidis; no PCR product was detected for 40 other serotypes and 28 different genera examined. In pure culture, 120 colony forming units (c.f.u.) could be detected; a PCR product was observed from template derived from a 5 h enrichment broth culture of chicken seeded with 1 c.f.u. per gram of Enteritidis. This PCR assay is specific, reproducible, and less time consuming than the standard bacteriological methods used to detect Enteritidis.
A hospital outbreak of salmonella food poisoning due to inadequate deep-fat frying
Authors: Evans M. R. , Hutchings P. G. , Ribeiro C. D. , Westmoreland D.
Published: May 2009

In an outbreak of plasmid-free Salmonella enteritidis phage type 4 (PT4) food poisoning at a hospital for mentally handicapped people in July 1990, 101 residents and 8 staff were affected and a cohort study implicated beef rissoles cooked by deep-fat frying as the vehicle of infection (relative risk 2·92, 95% confidence interval 1·73–4·93, P ≪ 0·001). Replication of the cooking process demonstrated that the rissoles achieved core temperatures of only 48–60 °C despite external temperatures of 91–95 °C and an oil temperature of 142–154 °C. No residual food was available for microbiological testing but plasmid-containing S. enteritidis PT 4 was isolated in shell eggs from the hospital kitchen.
Parasite prevalence in free-ranging farm cats,Felis silvestris catus
Authors: Yamaguchi N. , Macdonald D. W. , Passanisi W. C. , Harbour D. A. , Hopper C. D.
Published: May 2009

No animals tested were positive for feline leukaemia virus antigen andChlamydia psittaciantibodies, but all were positive for antibodies to feline calicivirus (FCV), feline herpesvirus 1 (FHV1) and rotavirus. They had antibodies to feline parvovirus (96%), feline coronavirus (84%) and cowpox virus (2%). Antibody to feline immunodeficiency virus (FIV) was found in 53% of animals, which were less likely to be infected withHaemobartonella felis, and had higher FHV antibody titres than cats without FIV. FCV was isolated from 51% cats and FHV1 and feline reovirus each from 4%.H. feliswas present in 42% of animals, and antibody toToxoplasma gondiiin 62%. Clinical abnormality had a significant association with FIV and feline calicivirus infections, but sex, age, social status and feeding group had no significant association with prevalence of any parasites.Toxocara catiandToxascaris leoninaeggs were found, respectively, in 91% and 82% of animals tested.
A mixed outbreak of cryptosporidium and campylobacter infection associated with a private water supply
Authors: Duke L. A. , Breathnach A. S. , Jenkins D. R. , Harkis B. A. , Codd A. W.
Published: May 2009

In an outbreak of gastroenteritis affecting 43 people, cryptosporidium and campylobacter were isolated from stool specimens and in two cases dual infection was found. All the cases had drunk unboiled water from a private untreated water supply.

Investigations revealed the carcasses of three lambs in a collection chamber connected with the water supply, and these, or run-off of slurry from surrounding fields, were the presumed source of contamination. Issues relating to the maintenance and monitoring of private water supplies are discussed. Problems with such supplies include old piping, proximity of livestock, inadequate knowledge of the layout and limited resources for monitoring and maintenance.
Nasal carriage of enterotoxin-producingStaphylococcus aureusamong restaurant workers in Kuwait City
Authors: Al Bustan M. A. , Udo E. E. , Chugh T. D.
Published: May 2009

Enterotoxin-producingStaphylococcus aureusis a common cause of staphylococcal food poisoning. To determine the incidence of carriage of enterotoxin-producingS. aureusin a sample of the healthy population in Kuwait city, restaurant workers in the city were screened for nasal carriage ofS. aureus. 26·6% of 500 workers studied carriedS. aureusand 86·6% of theS. aureusproduced staphylococcal enterotoxins. 28 % produced enterotoxin A, 28·5 % produced enterotoxin B, 16·4% produced enterotoxin C and 3·5% produced enterotoxin D. Ten isolates produced both enterotoxins A and B or A and C. 73 % of the isolates were untypeable with standard phages. However, 17·1%, 3% and 6% belonged to phage groups I, II and III respectively. The results demonstrated a high level of enterotoxigenicS. aureuscarriage among restaurant workers which although lower than that reported for the general population and hospital workers may be important in the restaurant industry.