bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistance in faecal Escherichia coli isolated from pigfarmers and abattoir workers
Authors: Nijsten R. , London N. , Bogaard A. Van Den , Stobberingh E.
Published: May 2009

Faecal samples collected from three populations of healthy adult volunteers (290 pigfarmers, 316 abattoir workers, 160 (sub)urban residents) living in the south of The Netherlands were analysed for the prevalence and degree of antibiotic resistance of Escherichia coli.

Significant differences in prevalence of resistance to amoxicillin, neomycin, oxytetracycline, sulfamethoxazole and trimethoprim were observed. The pig-farmers showed the highest percentages of resistance and the (sub)urban residents the lowest. In contrast no significant differences in high degrees of resistance were observed, except for neomycin.

Although both pigfarmers and abattoir workers have regular contact with pigs differences in prevalences of resistance were observed. However, because abattoir workers with intensive and less intensive pig(carcass) contact did not show significant differences, this is probably not the only important source of resistant E. coli in pigfarmers.

The high antibiotic use by pigfarmers (5%) and abattoir workers (8%) than by (sub)urban residents (0%) did not result in significantly different resistance percentages.
A community outbreak of haemolytic-uraemic syndrome in children occurring in a large area of Northern Italy over a period of several months
Authors: Tozzi A. E. , Niccolini A. , Caprioli A. , Luzzi I. , Montini G. , Zacchello G. , Gianviti A. , Principato F. , Rizzoni G.
Published: May 2009

From March to October 1993. 15 cases of haemolytic-uraemic syndrome (HUS) in children were detected in a large area of northern Italy, where only 8 cases had occurred in the previous 5 years. Analysis of stool and serum specimens obtained from 14 cases showed evidence of Verotoxin-producingEscherichia coli(VTEC) infection in 13. Serum antibodies to theE. coliO157 lipopolysaccharide (LPS) were found in 8 patients and to the O111 LPS in 2. An O86 VTEC was isolated from another patient. Fourteen children needed dialysis, and 1 died. No obvious epidemiologic link was observed among cases, most of whom lived in small townships. A case-control study did not show an association between HUS and food or exposure to cattle, but suggested an association with contact with chicken coops (OR = 6·5. 95% C.I. 1·2–34·9). However, VTEC were not isolated from stool samples obtained from the chicken coops involved. The risk factors for VTEC infection related to living in rural settlements, including the exposure to live poultry, should be considered in outbreak investigations.
Urinary isolates of apramycin-resistantEscherichia coliandKlebsiella pneumoniaefrom Dublin
Authors: Johnson A. P. , Malde M. , Woodford N. , Cunney R. J. , Smyth E. G.
Published: May 2009

Twenty-two gentamicin-resistant urinary isolates ofEscherichia coliand five gentamicin-resistant urinary isolates ofKlebsiella pneumoniaefrom a Dublin hospital were examined for resistance to the veterinary aminoglycoside antibiotic apramycin. Five isolates ofE. coliand one isolate ofK. pneumoniaewere found to be resistant. The apramycin-resistant isolates, which were also resistant to the veterinary anthelmintic agent hygromycin B, hybridized with a DNA probe for the gene encoding the enzyme 3-N-aminoglycoside acetyltransferase type IV (AAC(3)IV). Resistance to apramycin and hygromycin B was co-transferable in four of the five isolates ofE. coliand the isolate ofK. pneumoniae.In one isolate ofE. coliapramycin resistance was not transferable. On the basis of their restriction enzyme digestion profiles and the antimicrobial resistance traits encoded, the transferable plasmids encoding resistance to apramycin and hygromycin B comprised three distinct types. Genetic linkage between the gene encoding AAC(3)IV and genes encoding resistance to ampicillin and either tetracycline or trimethoprim, means that the relatively widespread use of these antimicrobial agents provides a selective pressure for the persistence of resistance to apramycin and gentamicin even in the absence of bacterial exposure to aminoglycosides.
Clonal diffusion of EPEC-likeEscherichia colifrom rabbits as detected by ribotyping and random amplified polymorphic DNA assays
Authors: Leroy-Setrin S. , Lesage M. C. , Chaslus-Dancla E. , Lafont J. P.
Published: May 2009

The genetic diversity and clonal relationships among 77Escherichia colistrains isolated in France from diarrhoeic rabbits and that belonged to seven O serogroups including the predominant O103 serogroup, were estimated by ribotyping and random amplified polymorphic DNA (RAPD) assays. Fifteen ribotypes were defined. Most of the highly pathogenic O103 strains could be assigned to two major groups. Non-pathogenic strains were clearly distinguished. RAPD assays generally matched ribotyping, or gave more precision for subdividing strains from the two main O103 groups. The results on strains isolated from different areas and over a 9-year period showed the relevance of the association of these two methods for the survey of the spread of strains in breeding flocks and illustrated clonal diffusion in rabbit production structures.
Molecular typing ofAcinetobacter baumannii–Acinetobacter calcoaceticuscomplex isolates from endemic and epidemic nosocomial infections
Authors: Ratto P. , Sordelli D. O. , Abeleira E. , Torrero M. , Catalano M.
Published: May 2009

Ribotype, biotype and resistance phenotype were used to characterize 37Acinetobacter baumannii–A. calcoaceticuscomplex isolates responsible for nosocomial infections in Buenos Aires. Nineteen isolates were recovered from endemic infections at 2 hospitals and 18 represent an intensive care unit outbreak that occurred in a third hospital. By ribotyping isolates were classified into five different clones ofA. baumanniibiotype 2, 3 ofA. baumanniibiotype 9, and 3 ofAcinetobactergenospecies 13. Combination of the three epidemiological markers permitted categorization of 18 outbreak isolates into four probable strains: 2A. baumanniibiotype 2. named type I. and II, and 2A. baumanniibiotype 9. Type I (15 isolates) was the most prevalent strain at one hospital and was responsible for the outbreak. In conclusion, combined analysis of biotypes, resistance phenotypes, and ribotypes was an accurate approach for epidemiologic investigation ofA. baumannii. Furthermore, ribotyping discriminatedAcinetobactergenospecies 13 isolates which were phenotypically difficult to type.
DNA typing of epidemiologically-related isolates ofAspergillus fumigatus
Authors: Birch M. , Nolard N. , Shankland G. S. , Denning D. W.
Published: May 2009

Invasive aspergillosis is often nosocomially acquired and carries a high mortality. Molecular typing methods to discriminate isolates have now been developed. Using simple restriction endonuclease (Sal1 andXho1) digestion of total genomic DNA, we have typed 25 epidemiologically-related isolates ofA. fumigatusfrom six hospital episodes of invasive aspergillosis. Eight DNA types were found and in each case the DNA type matched precisely the epidemiological data. Thus DNA typing ofA. fumigatuscan provide the means to match isolates from linked sources and distinguish isolates from diverse origins.
Genome variation in the SAT types of foot-and-mouth disease viruses prevalent in buffalo (Syncerus caffer) in the Kruger National Park and other regions of southern Africa, 1986–93
Authors: Vosloo W. , Kirkbride E. , Bengis R. G. , Keet D. F. , Thomson G. R.
Published: May 2009

Dideoxy nucleotide sequencing of a portion of the 1D gene of SAT-type foot-and-mouth disease viruses (FMDV) was used to derive phylogenetic relationships between viruses recovered from the oesophageo-pharyngeal secretions of buffalo in the Kruger National Park as well as several other wildlife areas in southern Africa. The three serotypes differed from one another by more than 40 % while intratypic variation did not exceed 29%. Within each type, isolates from particular countries were more closely related to one another than to isolates from other countries lending credence to previous observations that FMDV evolve independently in different regions of the subcontinent.
Correlation of change in phage type with pulsed field profile and 16S rrn profile in Salmonella enteritidis phage types 4, 7 and 9a
Authors: Powell N. G. , Threlfall E. J. , Chart H. , Schofield S. L. , Rowe B.
Published: May 2009

Using pulsed-field gel electrophoresis (PFGE) and 16S rRNA (rrn) analysis (ribotyping). the in viro derivation of strains of Salmonella enteritidis PTs 9a and 7 from a strain of S. enteritidis PT 4 has been demonstrated. All strains were isolated from a single patient over a 6-week period. Further studies have demonstrated that in terms of pulsed-field profile and ribotype, the genotypes of the patient-derived strains differed from those of the reference strains of the respective phage types. It is concluded that when used in combination, these methods can provide evidence of phylogenetic relationships in apparently unrelated S. enteritidis phage types isolated during pathogenesis of disease.
Presence ofSalmonellaspp. andCampylobacterspp. in shellfish
Authors: Wilson I. G. , Moore J. E.
Published: May 2009

Bivalve molluscs, (cockles, mussels, scallops and oysters) were examined according to EC shellfish bed classification regulations for faecal coliforms,Escherichia coliand salmonella, and for coliforms and campylobacter which are not specified by these regulations. Salmonella serotypes were detected in 8% of 433 molluscs. Seven salmonella isolations (2%) were made from category A beds, nominally suitable for immediate consumption according toE. colicounts. A higher percentage of salmonella isolates (6%) was detected in shellfish which require relaying or depuration prior to eating. In another survey, thermophilicCampylobacterspp. were found in 42% of 380 shellfish. These findings show that shellfish bed classification on the basis of indicator organisms alone is not sufficient to assure the absence of bacterial, and no doubt viral, pathogens. Depuration and end product specifications which require the absence of salmonellae are an essential part of these regulations. Microbiologists may wish to consider whether tests for pathogens such as salmonella and campylobacter should be included when determining the suitability of shellfish for human consumption.
Carriage of multiple ribotypes of non-encapsulatedHaemophilus influenzaein Aboriginal infants with otitis media
Authors: Smith-Vaughan H. C. , Leach A. J. , Shelby-James T. M. , Kemp K. , Kemp D. J. , Mathews J. D.
Published: May 2009

Ribotyping with the restriction enzymeXbaI was used to study the dynamics of carriage of non-encapsulatedHaemophilus influenzae(NCHi) in Aboriginal infants at risk of otitis media. Carriage rates of NCHi in the infants in the community were very high; the median age for detection was 50 days and colonization was virtually 100% by 120 days of age and persisted at a high level throughout the first year of life [1]. Eighteen different ribotypes of NCHi were identified from 34 positive swabs taken from 3 infants over a period of 9 months. The same ribotypes were recovered for up to 3 months from consecutive swabs of individual infants, and 12 of 27 swabs (44·4%) yielded two ribotypes from four colonies typed. Statistical analysis suggested that most swabs would have been positive for two ribotypes if enough colonies had been typed although the second most frequent ribotype was detected on average in only 13% of strains. Early colonization and carriage of multiple ribotypes of NCHi may help to explain the chronicity of carriage and thus the persistence of otitis media in Aboriginal infants.
Acute poststreptococcal glomerulo-nephritis in general practice: the contribution of infection to its onset and course
Authors: Higgins P. M.
Published: May 2009

Twenty-one patients considered to have acute poststreptococcal glomerulo-nephritis were encountered during 35 years of general practice. In ten of them good evidence of active streptococcal infection at the time of discovery of nephritis was recorded. The more complete the data the more convincing was the evidence of active infection.

In over half of those whose urines were routinely cultured pathogens were isolated and over a third were treated for infection of the urinary tract. Such infections were associated with adverse effects and prolonged illness.

As compared with children, adults in general had a longer history of ill-health, were less likely to present with acute infections and more likely to have urinary tract infections and prolonged illness.

Vigorous antistreptococcal treatment was followed by rapid recovery in those patients so treated whose illnesses were not complicated by urinary tract infections.

Concurrent streptococcal infection and secondary infection of the urinary tract may contribute more to the onset of acute poststreptococcal glomerulo-nephritis and to its course than is currently believed.
An epidemiological investigation of Norwalk virus infection in South Africa
Authors: Taylor M. B. , Parker S. , Grabow W. O. K. , Cubitt W. D.
Published: May 2009

A study was carried out to determine the incidence and seroprevalence of Norwalk virus (NV) in the Pretoria area, South Africa, using a recombinant NV (rNV) immunoassay for the detection of serum IgG antibodies. Maternal antibody was detectable in infants' sera up to approximately 6 months of age. Infection with NV was detected serologically in the second year of life and the seroprevalence of NV IgG rose from 37·1% at 7–11 months of age to 62·1% by the age of 40 years. No significant differences in seroprevalence of NV IgG antibody was evident between subjects of European or African ethnic origin, where overall seroprevalence rates were 56·4% and 53·9% respectively.
Pigs experimentally infected withSerpulina hyodysenteriaecan be protected from developing swine dysentery by feeding them a highly digestible diet
Authors: Siba P. M. , Pethick D. W. , Hampson D. J.
Published: May 2009

Weaner pigs (n= 72) were fed 1 of 4 diets. These were based on either cooked rice and animal protein, cooked rice and lupin, wheat and lupin, or wheat and animal protein. Twenty-six of the pigs were slaughtered after 1 month. Those fed the highly digestible cooked rice and animal protein diet had drier colonic contents and faeces, lighter large intestines, and the contents of their large intestines had increased pH values and decreased total VFA concentrations. The other 46 pigs were orally challenged with broth cultures ofSerpulina hyodysenteriae, and were monitored for faecal excretion of the spirochaetes, and for the development of swine dysentery (SD). None of 18 pigs fed the cooked rice and animal protein diet developed colonic changes or disease, whereas most pigs on the other diets developed mucohaemorrhagic colitis and dysentery. The reduced fermentation that occurred in the large intestines of pigs fed cooked rice and animal protein was associated with a subsequent failure of colonization byS. hyodysenteriae, and resultant protection against SD.
The concurrent prevalence of chloramphenicol-sensitive and multidrug-resistant Salmonella typhi in Vellore, S. India
Authors: Jesudason M. V. , John R. , John T. J.
Published: May 2009

A multidrug resistant (MDR) variety of Salmonella typhi emerged as the cause of epidemic typhoid fever in some Asian countries including India, during the late 1980s. We faced the epidemic from April 1990 to the first quarter of 1993. However, during this period we continued to isolate chloramphenicol sensitive (CS) S. typhi also. The relative prevalences showed that the frequency of CS variety was unaffected by the epidemic of MDR variety. This is an unusual epidemiological pattern, which indicates that there may have been factors which favoured the epidemic of the MDR variety but not the CS one.
Epidemiology of infection due to Escherichia coli O157: a 3-year prospective study
Authors: MacDonald I. A. R. , Gould I. M. , Curnow J.
Published: May 2009

A 3-year study of Escherichia coli infections in Grampian Region was conducted to ascertain the incidence, document clinical sequelae and identify at-risk groups. Approximately 30000 stools from patients with acute diarrhoea were screened for E. coli O157, and an epidemiological questionnaire filled in for each patient whose stool was positive. Eighty-three patients were studied. The annual incidence was 6 per 100000. Proportionately more infections occurred in people involved in agriculture. Evidence was seen of case-to-case transmission, and contamination of a water supply. Eight cases developed haemolytic uraemic syndrome (HUS). There were 2 deaths due to HUS and 2 due to haemorrhagic colitis (HC). Symptomatic E. coli infection is relatively common in the Grampian Region, more common in the agricultural community, and is the main cause of HUS in this Region.
The use of saliva for viral diagnosis and screening.
Authors: Mortimer Philip P. , Parry John V.
Published: May 2009

The strength and diversity of antibody responses to infection are the basis for many of the most rapid and sensitive tests in virology, yet the need to obtain the patient's consent and co–operation, to collect blood from a vein and to separate the serum before the test often deters investigators, particularly if children are involved or if there is added risk, difficulty or cost in doing the venepuncture.
Occurrence of ‘thermophilic’ campylobacters in sewage and their removal by treatment processes
Authors: Arimi S. M. , Fricker C. R. , Park R. W. A.
Published: May 2009

Removal of thermophilic campylobacters from sewage at three different stages of treatment at a trickling filter sewage works has been assessed. Samples of incoming sewage, primary sedimentation effluent and final effluent were taken daily from 06.00 h to 20.00 h for 5 consecutive days and the numbers of campylobacters determined by using a most probable number method. Each sample was cultured using 2 h pre–enrichment followed by enrichment in Preston broth for 48 h and detection by plating. Over 78% of the incoming campylobacters were removed after primary sedimentation and < 0.1% remained in the final effluent.Campylobacter jejunbiotype I and biotype II constituted 81.5% and 15.9% respectively of the 232 isolates tested. Serotypes common in sewage were common in human faces. It appears that the trickling filter sewage works removes most of the campylobacters entering the sewage works, but large numbers, estimated to be approximately 1010, are released into the environment daily from a local sewage works.
The pathogenicity of environmental campylobacters-a human volunteer experiment
Authors: Mawer S. L.
Published: May 2009

Three human volunteer experiments were performed in which river water expected to contain campylobacter organisms was ingested. Despite the ingestion of over 44000 organisms in one experiment, the subject did not suffer any symptoms, nor were campylobacter organisms excreted, nor was an antibody response to the ingested strains detected. The campylobacter organisms ingested resembledCampylobacter jejunion colonial and microscopic morphology but were hippurate negative, and were distinct fromC. coli. These environmental campylobacter strains appear to be non-pathogenic, however they may be mistaken forC. JejuniorC.coliif they are not fully identified.
An outbreak of cryptosporidiosis in a hospital day-care centre
Authors: Cristino J. A. G. Melo , Isabel M. , Carvalho P. , José Salgado Maria
Published: May 2009

The investigation of an outbreak of cryptosporidiosis in a hospital day-care centre is reported. Twenty-eight (27%) children and one member of the staff were infected. Most of the cases were symptomatic and the major presenting symptom was watery diarrhoea. Shedding of oocysts continued for a mean of 12 days after diarrhoea had subsided and most of the cases were still excreting oocysts when the first follow-up sample was examined. Intermittent shedding or a carrier state were not seen in any of the cases.Giardia intestinaliscysts were detected in 19 children, 7 of whom showing mixed infection withCryptosporidiumsp., but this association was not statistically significant. All cases recovered without specific therapy. No definite proof could be found to demonstrate the source of the outbreak or the route of transmission but some observations suggesting person-to-person transmission are discussed.
Changes in the epidemiological pattern ofMycoplasma pneumoniaeinfections in Denmark
Authors: Lind K. , Bentzon M. W.
Published: May 2009

A seroepidemiological survey has shown a remarkable shift in the previously reported regular cyclic pattern ofMycoplasma pneumoniaeepidemics which culminated every 4·5 years during the period 1958–74. The last of four regular epidemics occurred in 1972. It was followed by ‘premature’ epidemics in 1975 and 1977/8 which inaugurated a change from an epidemic to an endemic pattern of the infection in Denmark. Over the following 9 years (1978–86) there has been an irregular but significant decrease in the annual number of seropositive samples with the usual high incidence during winter seasons. This endemic period terminated in the fourth trimester of 1987 with the development of a new epidemic. The hypothesis is advanced that a sixfold increase of children in day care may have influenced the change from an epidemic to an endemic situation which after 9 years led to a new epidemic ofM. pneumoniaeinfection.
Chlamydial antibodies in farmers in north-west England
Authors: Hobson D. , -Capner P. Morgan
Published: May 2009

Because of recent reports of abortion in farmers' wives following infection with ovine strains ofChlamydia psittaciduring pregnancy, the distribution of chlamydial antibodies was studied in rural populations in north-west England, where endemic chalamydial infection with abortion in common in sheep. Immunoperoxidase assays withC. treachomatisand ovineC. psittacishowed no significant differences in either the frequency or titres of antibodies between sheep farmers and other types of farmer or non-farming adults living in the same areas. The frequency and titers of antibodies in farmers' wives were no greater than in farmers, and were unrelated to their previous obstetric history or type of farming. Overall, 62/255 (24%) of this rural population had antibody detected byC. trachomatisantigen and only 30/255 (13%) detected byC.Psittaciantigen. The possible significance of these findings is discussed. This survey does not suggest that the risk of infection withC.psittaciis especially high in people working with sheep, but the complications following infection during pregnancy deserve the specific instructions that have been given to pregnant women to avoid exposure, especially during lambing, in farming and veterinary work.
Pneumococcal carriage amongst children in Adelaide, South Australia
Authors: Hansman D. , Morris Sylvia
Published: May 2009

Amongst 1267 healthy children 6 months to 4.5 years of age in Adelaide, the pneumococcal carriage rate from a single nasal swab sampling was 29% in the period 1980–1. Of 269 children, sampled monthly on five occasions, 91% carried a pneumococcus on one or more occasions: 55% carried a single type, 33% carried two types, 2% carried three types and 1% carried four types; 18% carried a pneumococcus on either 4 or 5 occasions. The commonest types encountered were types 6, 19 and 23 in that order, and these three types constituted 57% of the total: other common types(> 5% of the total) were types 14, 15 and 11, and the six commonest types constituted 77% of the total. Of these, types 6, 14, 19 and 23 commonly cause systemic disease in children; on the other hand types 11 and 15 cause disease infrequently. The number of strains showing antimicrobial drug resistance was low: on quantitative testing 0.7%of 291 isolates examined showed relative resistance to benzylpenicillin and 0.7% were resistant to tetracycline; 10.9% of 230 isolates examined showed resistance to co-trimoxazole; dual or multiple drug resistance was not detected, and all isolates tested were susceptible to chloramphenicol, erythromycin, lincomycin and rifampicin.
Faecal excretion of rotavirus and other enteropathogens in newborns of the high and low socio-economic stratum in Santiago, Chile
Authors: Spencer E. , Araya M. , Sandino A. M. , Pacheco I. , Brunser O.
Published: May 2009

Faecal excretion of enteropathogens was studied in newborns in their first week of life. Rotavirus was investigated in 225 neonates, of whom 107 belonged to the low socio-economic stratum (SES) and 118 to the high SES. Half of each group were delivered by caesarean section. Rotavirus was detected in 10 infants (4.4%). Eight of them had been in the same ward and excreted the same viral electrophoretype. Enteropathogenic bacteria were isolated from 8 out of 57 (14–0%) newborns. Positive cultures were equally distributed by SES and route of delivery.Giardia lambliawas the only parasite detected, in one infant (2–6%) of the high SES. None of the children developed symptoms. Faecal excretion of enteropathogens ended spontaneously within a week in all cases. It is suggested that the lack of symptomatology and the spontaneous termination of the faecal excretion are related to immaturity of the small intestinal mucosa, that does not allow the completion of the steps that must take place during a successful infectious event.
Potential allergens in oil emulsion foot-and-mouth disease vaccines for pigs
Authors: Black L. , Francis M. J
Published: May 2009

Reactions so far reported after the use of oil emulsion (OE) foot-and-mouth disease (FMD) vaccines in pigs have been infrequent and quick to resolve themselves. Although tentatively ascribed to anaphylaxis, these reactions have received little attention and their mechanism of causation has not been established conclusively.
A Prospective study of genital infections in a family planning clinic: 2. Chlamydia infection - the identification of a high-risk group
Authors: Macaulay M. E. , Riordan T. , James J. M. , Leventhall P. A. , Morris E. M. , Neal B. R. , Ellis D. A.
Published: May 2009

During a study of genital infection in inner-city family-planning patients we examined 452 women for Chlamydia trachomatis. The prevalence of infection was 7·3%. There was no significant difference between patients attending because of genital symptoms and those who were attending for routine family-planning advice. Infection was found to be correlated with five main demographic parameters; age less than 25, no stable partnership, hormonal contraception, nulliparity and West Indian Ethnic origin. Using these parameters a simple scoring system was devised which allowed a high-risk population to be defined in whom screening would be economically justified.
High incidence of subacute sclerosing panencephalitis in South India
Authors: Saha V. , Jacob John T. , Mukundan P. , Gnanamuthu C. , Prabhakar S. , Arjundas G. , Sayeed Z. A. , Kumaresan G. , Srinivas K.
Published: May 2009

During 19837 a clinical diagnosis of subacute sclerosing panencephalitis (SSPE) was confirmed by the detection of measles virus haemagglutination inhibiting antibody in the cerebrospinal fluid (CSF) in 81 subjects resident in Tamilnadu. The antibody titre (reciprocol of the endpoint dilution) in the CSF ranged from 2 to 32 and in the sera from 8 to 2048. The CSF: serum ratios of titres were 1:41:64 in 80 cases and 1:128 in one case. The median age at onset of SSPE was 10 years and 97% of cases were diagnosed at stage 2 and beyond. Based on the geographic distribution of 72 cases in an estimated population of 84 million, the annual incidence of SSPE was calculated to be 214 per million population, or 43 cases per million children below 20 years. Assuming that only 10% of all cases would have reached the level of laboratory diagnosis, the incidence may be as high as 21 cases per million population.
Antibiotic resistance among salmonella from human and other sources in New Zealand
Authors: Heffernan H. M.
Published: May 2009

Of 2210 salmonella isolates referred to the New Zealand Communicable Disease Centre for epidemiological surveillance during 1987, 147 (6·7%) were resistant to one or more of 10 antibiotics. Resistance to streptomycin was most common (4·5%). followed by sulphamethoxazole (3·4%), tetracycline (3·3%), ampicillin (1·5%). and kanamycin (1·4%). Resistance to cephalothin, chloramphenicol, gentamicin and trimethoprim occurred in less than 1 % of isolates. There was no resistance to norfloxacin. Isolates from human sources were significantly (P < 0·001) more resistant (10%) than those from other sources (3·2%). The majority of resistant isolates were resistant to more than one antibiotic, but multiresistance to five or more antibiotics occurred only among human isolates. Comparison of these results with data from earlier years shows that there has been little change in the incidence of resistance among salmonella in this country over the last 10 years. The prevalence of antibiotic resistance among salmonella in New Zealand is low relative to many other countries.
Waterborne transmission and the evolution of virulence among gastrointestinal bacteria
Authors: Ewald P. W.
Published: May 2009

Diarrhoeal diseases are primary contributors to millions of deaths annually. Yet, little is known about the evolutionary reasons for the differences in virulence among gastrointestinal pathogens. Applying the comparative, cost/benefit approach of evolutionary biology this paper proposes that waterborne transmission should favour evolution towards high virulence. This hypothesis is supported by a cross-specific test, which shows that waterborne transmission is strongly correlated with the virulence of bacterial gastrointestinal pathogens of humans. Alternative explanations of this correlation are not supported by available data. These findings bear on public health policy because they draw attention to a previously unrecognized long-range benefit gained from purification of water supplies: diarrhoeal pathogens may evolve to lower levels of virulence.
Genetic relationships among strains ofNeisseria meningitidiscausing disease in Italy, 1984–7
Authors: Mastrantonio P. , Congiu M. E. , Selander R. K. , Caugant D. A.
Published: May 2009

Since 1984 a change in the epidemiological pattern of meningococcal disease in Italy has occurred with a predominance ofNeisseria meningitidisof serogroup C (76%), serotype 2a and a high proportion of strains resistant to sulphonamides (71%). In order to understand better the epidemiology of the groupC N. meningitidisstrains responsible for the disease over the last years in Italy, we studied the genetic features of phenotypically closely related strains, by enzyme electrophoresis. The results showed that the genetic and the phenotypic characteristics of the 57 strains studied were similar, suggesting the spread of a single clone during recent years in our country.

This result is in agreement with the circulation of strains typical of epidemic situations, despite the decreasing incidence of meningoccal disease in Italy.
Epidemiology of bluetongue and related orbiviruses in the Sultanate of Oman
Authors: Al-Busaidy S. M. , Mellor P. S.
Published: May 2009

Sentinel herds at 34 farms were used to study the epidemiology of bluetongue and related orbiviruses in Oman. The results indicate that bluetongue virus (BTV) is widespread and is enzootic in Northern Oman. At least three BTV serotypes (3, 4 and 22) were present at the time of the study. Antibodies to epizootic haemorrhagic disease of deer virus (EHDV) type 2 and EHDV-318 were also detected but were less prevalent. Entomological investigations identified the presence of 16 species ofCulicoides. The peak seasonal incidence of the BTV vectorC. imicolaand the EHDV vectorsC. schultzei(group) midges at Rumais in Northern Oman correlated closely with the spring rains in that area. However, both species of midge were also present in lower numbers throughout the year. Four species of Omani midge,C. arabiensis, C. ibriensis, C. neoschultzeiandC. buettikeriare new to science.
Acquisition and invasiveness of different serotypes of Streptococcus pneumoniae in young children
Authors: Smith T. , Lehmann D. , Montgomery J. , Gratten M. , Riley I. D. , Alpers M. P.
Published: May 2009

Rates of acquisition and mean duration of nasal carriage of different serotypes of Streptococcus pneumoniae have been estimated by fitting a stochastic model to longitudinal carriage data in children from Papua New Guinea. Immunogenicity and two indices of relative invasiveness were determined for each serotype. Immunogenic serotypes were less frequently acquired and were carried for shorter periods, but no relationship between immunogenicity and invasiveness was apparent using either index of invasiveness. Frequent invasion was associated with a high acquisition rate and high frequency and prolonged duration of carriage. Carriage studies can provide a broad indication of which serotypes cause invasive disease but not the proportion of disease due to individual serotypes; some serotypes which cause invasive disease (e.g. serotype 46) are not found even in extensive carriage studies. The antibiotic resistance of carriage organisms, however, does approximate the resistance patterns of invasive organisms and thus may be used to monitor changing patterns of antimicrobial susceptibility in the community.
Comparison of multilocus enzyme electrophoresis (MEE), ribotyping, restriction enzyme analysis (REA) and phage typing for typing ofListeria monocytogenes
Authors: Nørrung B. , Gerner-Smith P.
Published: May 2009

The discriminatory power of four methods for typing ofListeria monocytogeneswas compared. The four methods were multilocus enzyme electrophoresis (MEE), ribotyping, restriction enzyme analysis (REA), and a newly developed Danish phage typing system. Ninety-nine human clinical, food and slaughterhouse isolates ofListeria monocytogeneswere typed by each method. The most discriminatory single typing method was phage typing with an overall discriminatory index (DI) of 0·88 followed by REA, MEE and ribotyping with DI-values at 0·87, 0·83 and 0·79 respectively. Considering strains from each of the two predominant O-serotypes alone, serotype 1 was best discriminated by the molecular typing methods, in particular REA, which showed a DI of 0·92. The serotype 4 strains were best discriminated by phage typing (DI = 0·78). If two or more typing methods were combined, the combination of REA and MEE were found to be the most discriminatory combination. The DI values were 0·96, 0·74 and 0·90 for serotype 1, 4, and both combined, respectively. Phage typing is a rapid and inexpensive typing method but not as reproducible as the molecular typing methods. It is the most suitable method for mass screening. In situations where results are required to be highly reliable, i.e. when studying the relationships between only a few strains, a single or a combination of molecular typing methods should be used, preferable MEE and REA.
Comparison of serotype, biotype and bacteriocin type with rDNA RFLP patterns for the type identification ofSerratia marcescens
Authors: Alonso R. , Aucken H. M. , Perez-Diaz J. C. , Cookson B. D. , Baquero F. , Pitt T. L.
Published: May 2009

Variations in rDNA gene loci in DNA digests of 209 clinical isolates ofSerratia marcescenswere determined with anEscherichia colirRNA probe. Forty-one restriction fragment length polymorphism patterns (ribotypes) were identified, based on the size of 4–14 (mean 7·5) hybridization bands. The patterns differed by more than a single band in 98% of pair-wise comparisons. On a subset of 76 isolates, ribotyping proved to be marginally more discriminating than biotyping (discrimination index 0·92v. 0·89) followed by serotyping (0·87) and bacteriocin typing (0·74). About one-third of isolates belonged to unique ribotypes and only two ribotypes exceeded 5% in frequency (23·0 and 6·4% respectively). A combination of serotype or biotype with ribotyping defined a similar number of strains, although none of the methods alone was sufficiently discriminatory to identify strains. We conclude that due to the accessibility of biotyping and the lack of commercially available antisera forS. marcescens, the biotype and ribotype together provide reliable markers of strain identity.
A comparison of multiple drug resistance in salmonellas from humans and food animals in England and Wales, 1981 and 1990
Authors: Threlfall E. J. , Rowe B. , Ward L. R.
Published: May 2009

For Salmonella typhimurium from humans in England and Wales, the incidence of multiple resistance more than doubled over the 8-year period 1981–8 and, over the next 2 years, increased by a further 7%. From 1981 to 1988 both resistance and multiple resistance also increased significantly in S. virchow and although multiple resistance did not increase over the next 2 years, the overall incidence of resistance has continued to rise. In 1990 the majority of S. typhimurium from cattle were multiply-resistant and the occurrence of such resistance has quadrupled since 1981. Multiple resistance has also increased in S. typhimurium from pigs and, to a lesser extent, from poultry. In contrast, multiple resistance has remained uncommon in the poultry-associated serotype S. enteritidis. For S. virchow, multiple resistance was common in a phage type frequently associated with poultry meat imported from France.

The continuing use of a range of different antimicrobials in calf husbandry has been an important factor in promoting the emergence of multiply-resistant strains of S. typhimurium in cattle. In contrast, multiple resistance has remained rare in those serotypes associated with poultry, where the use of such antimicrobials has been less intensive.

It is hoped that recent recommendations discouraging, in veterinary medicine, the prophylactic use of antibiotics with cross resistances to those used in human medicine will result in a reduction in the occurrence of multiresistant strains in food animals and subsequently in humans.
Variations in biochemical phenotypes and phage types ofSalmonella enteritidisin Germany 1980–92
Authors: Katouli M. , Seuffer R. H. , Wollin R. , Kühn I. , Möllby R.
Published: May 2009

The Phene Plate system for typingSalmonellaserotypes (PhP-S) is a simple automated typing method based on biochemical fingerprinting. It gives a quantitative value of the metabolism of various substrates by measuring the speed and intensity of each reaction. The ‘biochemical fingerprint’ of each isolate is used to calculate similarities among the tested strains with a personal computer program. We used this system to examine a collection of 86 strains ofSalmonella enteritidisisolated from human sporadic cases in Germany between 1980 and 1992. Twenty-three biochemical phenotypes (BPTs) consisting of 9 common (C) and 14 single (S) BPTs were identified. BPTs C2 and C4 containing 20 and 36 strains respectively accounted for 65% of the isolates. Strains of BPT C2 were found over a wide period of time whereas strains of BPT C4 were isolated during the period between 1988 and 1992. With phage typing, 11 discrete phage types (PTs) and 18 strains designated as non-specific type (NST) were identified. PTs 4 and 8 with 39 and 17 strains respectively were the dominant PTs. Strains of PT 8 were isolated over a wide period of time whereas all (except one) strains of PT 4 were isolated between 1988 and 1992. Combination of biochemical fingerprinting and phage typing divided the strains into 25 phenotypes (BPT:PTs). Whilst phenotype C2:8 was found over a number of different years, phenotype C4:4 was isolated only between 1988 and 1992. These findings indicate the presence of one persistent and one recently emerged phenotype amongS. enteritidisstrains in Germany. Although both methods identified the presence of both major and less common types, biochemical fingerprinting with the PhP-S system also provided information about relationships between the strains.
The prevalence of antimicrobial resistance in human faecal flora in South Africa
Authors: Shanahan P. M. A. , Wylie B. A. , Adrian P. V. , Koornhof H. J. , Thomson C. J. , Amyes S. G. B.
Published: May 2009

Between January and March 1992, 361 faecal specimens were collected from the healthy black population in the Transvaal Province of South Africa. Each specimen was examined for the prevalence of antimicrobial resistance in commensal bacteria. Volunteers, from both rural and urban dwellings, were divided into four age groups. The overall carriage rate of resistance varied from 88.6% for ampicillin, 74.2% for trimethoprim, 52.6% for chloramphenicol, 10.2% for nalidixic acid to 7.5% for gentamicin. The carriage of resistance found to each individual antimicrobial agent was slightly higher in the rural population rather than the urban population but there was no correlation between the prevalence of antimicrobial resistance and the age group.
Healthy individuals possess circulating antibodies against their indigenous faecal microflora as well as against allogenous faecal microflora: an immunomorphometrical study
Authors: Apperloo-Renkema H. Z. , Jagt T. G. , Tonk R. H. J , van der Waaij D.
Published: May 2009

Healthy persons were shown to possess circulating antibodies of both IgA, IgG and IgM isotype directed against the bacteria of their faecal microflora, assessed by immunomorphometry. After removal, by absorption, of the fraction of antibodies directed against the autochthonous faecal bacteria or cross-reacting with allogenous faecal bacteria, there were still antibodies left directed against allogenous faecal bacteria of both the IgA, IgG and IgM isotype. However, relatively more antibodies of the IgA isotype appeared to be directed against allogenous bacteria than against indigenous faecal bacteria. Persons who reacted with specific antibodies to many bacteria of their own flora also tended to react specifically to bacteria in the allogenous microflora of the other volunteers. The patterns of antibodies directed to faecal bacteria of different morphologies (morphotypes) were unique for each individual.
Impact of respiratory virus infection in patients with chronic chest disease
Authors: Wiselka M. J. , Kent J. , Cookson J. B. , Nicholson K. G.
Published: May 2009

This study investigated the morbidity associated with respiratory virus infections in patients with well-documented chest disease, and the risk of transmission between close contacts. Patients informed the study team if they were exposed to a family member or colleague with a cold. Patients and symptomatic index cases recorded respiratory symptoms during the study period. Acute nasopharyngeal swabs and paired sera were obtained for viral diagnosis.

Twenty-five (43%) of 58 recorded exposures resulted in a symptomatic illness and 16 (28%) patients developed lower respiratory tract symptoms. Sixteen (64%) of the 25 symptomatic patients contacted their general practitioner, 14 (56%) received antibiotics and 4 (16%) were hospitalized. Mean duration of illness was 10·6 days in symptomatic patients and 5·7 days in their corresponding index cases (P < 0·005). Mean symptom scores were 100·6 in symptomatic patients and 62.2 in index cases (P < 0·01). Respiratory viruses were identified in 19 (33%) episodes. Rhinovirus, coronavirus and respiratory syncytial virus infections were all associated with lower respiratory tract exacerbations.

Respiratory tract symptoms following exposure to a cold were comparatively severe in these patients with chronic chest disease. This group of patients might gain particular benefit from the introduction of effective vaccines or antiviral therapy.
Laboratory surveillance of viral meningitis by examination of cerebrospinal fluid in Cape Town, 1981–9
Authors: McIntyre J. P. , Keen G. A.
Published: May 2009

Nine years accumulated laboratory data derived from the culture of the cerebrospinal fluid of 11 360 aseptic meningitis cases were retrospectively reviewed to establish the epidemiology of viral meningitis in Cape Town. Virus was isolated from 3406 of the cases (91% enteroviruses and 9% mumps).

Five major summer viral meningitis episodes were documented: two of echovirus 4 (706 and 445 cases), echovirus 9 (223), coxsackie A9 (104) and one of unidentified enterovirus (324 cases – probably echo 9). Although coxsackie B was endemic, clusters of one or other type were dominant at any one time. Mumps was endemic. Sixty-two percent of all viral cases were <5 years old. The median ages of 4 and 5 years in echoviruses 9 and 4 (the epidemic strains) contrasted with that of 1 year in coxsackie B (with many cases <3 months old). Mumps peaked at 3–4 years of age. Males dominated overall, particularly in mumps.
Characterization of monoclonal antibodies against a type SAT 2 foot-and-mouth disease virus
Authors: Crowther J. R. , Rowe C. A. , Butcher R.
Published: May 2009

This paper is the first to describe characterization of monoclonal antibodies (MAbs) against a South African Territories 2 (SAT 2) foot-and-mouth disease virus (isolate Rho 1/48). Twelve MAbs which neutralized homologous virus were characterized in indirect and sandwich ELISA using purified Rho 1/48 virus particles, subunits, trypsin-treated, and chemically denatured virus. All the Mabs inhibited haemagglutination by parental virus. Binding of the MAbs to 73 SAT 2 field isolates was measured in a sandwich ELISA and defined four distinct antigenic regions. Preliminary characterization of escape mutants selected with some of the MAbs using virus neutralization tests, ELISA, and amino acid sequencing is included. MAbs 2, 25, 40, 48 and 64, reacted with a linear epitope on the VP1 loop region. An amino acid change at position 149 (valine to glutamic acid) was detected in mutants selected by MAb 2 and 40 and this eliminated binding and neutralization by all the other MAb. This epitope was conformation-dependent and was conserved in all 73 isolates of SAT 2 examined. Escape mutants isolated with MAb 41 and 44, had changes at positions 156 (glycine to aspartic acid), or 158 (serine to leucine) respectively. These MAbs bound with Rho 1/48 only out of 73 field strain viruses studies and the reactions of MAbs from the other groups was unaltered. MAb 27, 28 and 37 reacted with a conformation-dependent epitope on VP1 which was not conserved in field isolates. All mutants selected by these MAbs had a single amino acid substitution at position 149 (valine to alanine). The same change was always found in field isolates which did not bind MAbs from this group. MAb 11 reacted with a linear epitope associated with amino acids 147 or 148 on VP1 and showed similar binding characteristics to a conformation dependent MAb 7, no amino acid residue changes were found within VP1 for monoclonal antibody 7 mutants.
Distinct yearly change of serotype distribution of human rotavirus in Thailand as determined by ELISA and PCR
Authors: Pongsuwanna Y. , Taniguchi K. , Wakasugi F. , Sutivijit Y. , Chiwakul M. , Warachit P. , Jayavasu C. , Urasawa S.
Published: May 2009

A total of 241 group A rotavirus-positive stool samples collected from diarrhoeic patients in Thailand between July 1988 and June 1991 were characterized for their serotypes by enzyme-linked immunosorbent assay (ELISA) using serotype-specific monoclonal antibodies and by a polymerase chain reaction (PCR). In July 1988–June 1989, serotype 1 was the most prevalent (63·4%), followed by serotype 4 (11·0%) and serotype 2 (8·5%). In July 1989–June 1990, 59·8% were serotype 1, 24·3% were serotype 2, and 6·1 % were serotype 3. In contrast, in July 1990–June 1991, serotype 3 was detected in the highest frequency (40·5%), 29·9% were serotype 1, and 27·3% were serotype 2. Thus, a distinct yearly change of serotype distribution of rotavirus in Thailand was observed in the three consecutive years. In particular, it was of note that the prevalence of serotype 3 greatly increased, in contrast to the previous studies in which almost no serotype 3 rotaviruses were detected in the years 1983–8 in Thailand.