bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigenic characteristics of Borrelia burgdorferi isolates from ixodid ticks in California
Authors: Lane R S , Pascocello J A
Published: January 2020

Twenty (1.4%) of 1,421 adult Ixodes pacificus ticks and 2 (20%) of 10 adult Ixodes neotomae ticks collected in five counties of northern California were found to contain spirochetes by direct immunofluorescence examination of their tissues with a polyvalent conjugate. Borreliae isolated from the tissues of nine of these ticks (I. pacificus, 8; I. neotomae, 1) were identified as Borrelia burgdorferi with specific monoclonal antibodies and characterized further by polyacrylamide gel electrophoresis and Western blot (immunoblot) analyses. The isolate from I. neotomae was the first to be characterized from a tick other than I. pacificus in western North America. All strains were relatively homogeneous with respect to the kind of OspA proteins they produced, whereas they were heterogeneous with regard to their OspB proteins and to several low-molecular-weight proteins in the 21,500-to-24,000 region. Significant phenotypic variation was observed among isolates obtained within and between populations of I. pacificus. This investigation nearly doubles the number of isolates of B. burgdorferi that have been characterized from ixodid ticks in the far western United States.
Molecular techniques for the detection of Chlamydia trachomatis
Authors: Peterson E M , Oda R , Alexander R , Greenwood J R , de la Maza L M
Published: January 2020

A DNA probe assay (PACE; Gen-Probe, San Diego, Calif.) was compared with a culture reference method for the detection of Chlamydia trachomatis. Using stock isolates of each of the 15 serovars (A to K, Ba, L1, L2, and L3) of C. trachomatis, the lower limit of sensitivity for the DNA probe ranged between 1,086 inclusion-forming units (IFU) for serovar E (Bour) to 2,930 IFU for serovar L1 (440), with the only exception being serovar C (TW-3), with which 99 IFU was detected. There was no cross-reactivity with Chlamydia psittaci (Texas turkey) and Chlamydia pneumoniae (TWAR-183). Bacterial and fungal isolates representing 14 species of normal vaginal flora as well as Neisseria gonorrhoeae gave negative results with the DNA probe when tested at a level of 1.5 X 10(7) CFU/ml. In addition, the DNA probe, a direct fluorescent-antibody stain (DFA) (MicroTrak; Syva Corp., Palo Alto, Calif.), and an enzyme-linked immunosorbent assay (Chlamydiazyme; Abbott Laboratories, North Chicago, Ill.) were compared with culture for the detection of C. trachomatis, using 196 clinical cervical samples. Of the 196 samples, 20 (10%) were culture positive. Of the 176 culture-negative samples, 1 was not evaluated by DNA probe and 4, because of a lack of cellular material, were not evaluated by DFA. The sensitivities of the DNA probe, DFA, and enzyme-linked immunosorbent assay were 60, 75, and 85%, respectively, and specificities were 95, 99, and 97%, respectively. Of the false-positive direct results, there was only one specimen with which more than one direct method was positive, and with this specimen all three direct methods were positive. The majority of false-negative results by the direct methods were from specimens which by the culture method gave <100 IFU per culture.
Comparison of buffalo green monkey cells and McCoy cells for isolation of Chlamydia trachomatis in a microtiter system
Authors: Krech T , Bleckmann M , Paatz R
Published: January 2020

A total of 1,229 urogenital samples of patients with sexually transmitted diseases and prostitutes were inoculated simultaneously in McCoy cells and Buffalo green monkey (BGM) cells by using a microtitration technique. BGM cells proved to be slightly more sensitive than McCoy cells, and they usually showed more and larger inclusions and were more resistant to cytotoxic substances in samples. The decrease in sensitivity as a result of mycoplasmal contamination was much more prominent in McCoy cells than in BGM cells.
Evaluation of Spectrum-10 system for identification of members of the family Enterobacteriaceae
Authors: Vuye A
Published: January 2020

A total of 378 isolates of the family Enterobacteriaceae were tested with conventional biochemical tests and with the Spectrum-10 identification system. Of these, 97.4% were correctly identified to the species level by using the seven-digit profile of Spectrum-10. The preliminary four-digit profile provided the correct species for 61.1% and the correct genus for 79.4% of the strains. Most misidentifications were observed with aberrant biotypes of Citrobacter freundii.
"Campylobacter upsaliensis" isolated from cats as identified by DNA relatedness and biochemical features
Authors: Fox J G , Maxwell K O , Taylor N S , Runsick C D , Edmonds P , Brenner D J
Published: January 2020

Campylobacter spp. were isolated from the feces of 20 (58%) of 53 asymptomatic cats during routine physical examination while the cats were maintained in an accredited quarantine facility. Fifteen of these Campylobacter spp. were identified phenotypically as Campylobacter jejuni, and two were identified as C. coli. DNA-DNA hybridization (hydroxyapatite method) was used to confirm the identification of three thermotolerant catalase-negative isolates. They were 80 to 100% related to each other and to the type strain of "C. upsaliensis" in reassociation reactions under optimal conditions and a stringent hybridization criterion. These strains were 75 to 100% interrelated and less than 12% related to type strains of other Campylobacter species. These strains represent the first reported feline isolate of "C. upsaliensis" and show that cats used in biomedical research can harbor this and other Campylobacter species.
Detection of asymptomatic Clostridium difficile carriage by an alcohol shock procedure
Authors: Clabots C R , Gerding S J , Olson M M , Peterson L R , Gerding D N
Published: January 2020

Direct inoculation to cefoxitin-cycloserine-fructose agar and broth was compared with alcohol shock-chopped meat broth inoculation for optimal detection of Clostridium difficile in fecal samples. Alcohol shock is significantly more sensitive than cefoxitin-cycloserine-fructose agar or broth and may be the method of choice to detect C. difficile in asymptomatic carriers.
Establishment of 2-docosanol as a cellular marker compound in the identification of Mycobacterium xenopi
Authors: Larsson L , Jiménez J , Valero-Guillén P , Martín-Luengo F , Kubín M
Published: January 2020

Sixteen strains of Mycobacterium xenopi were studied by gas chromatography and thin-layer chromatography. Data on the cellular fatty acids, fatty alcohols, mycolic acids, and glycolipids indicated that this bacterium possesses a specific lipid composition. 2-Docosanol, detected in all studied strains, was found to constitute a useful chemical marker in the identification of M. xenopi.
Applications of a new method for devising bacteriological serotyping schemes
Authors: Thompson C J , Bettelheim K A
Published: January 2020

Greatly simplified serotyping schemes were devised for two organisms, Escherichia coli and Campylobacter jejuni. The mathematical approach developed to improve the E. coli serotyping routine at the National Health Institute in New Zealand was used on three previously published data sets. It had been considered possible that the mathematical method used in the first study was specific to that data set and therefore not applicable elsewhere. This paper verifies that the mathematical method works on two other E. coli collections and on another bacterium, C. jejuni, and therefore greatly strengthens the assertion made in the earlier paper (C.J. Thompson, J. Clin. Microbiol. 25:774-780, 1987) that this mathematical approach has general applications and can be used to produce efficient and effective serotyping schemes in any laboratory choosing to apply the method to its set of sera.
Standardization of yeast inocula with an electronic impedance counter
Authors: Eng C , Valenstein P
Published: January 2020

The standardization of yeast inocula has been identified as an important variable in the performance of reproducible in vitro fungal susceptibility testing. We investigated the precision and accuracy of an electronic particle counter in preparing yeast inocula, with quantitative culture used as a "gold standard." Suspensions of Candida albicans and Torulopsis glabrata standardized with a particle counter at 10(6) counts per ml were highly reproducible when cultured quantitatively (coefficients of variation, 6.7 and 6.8%, respectively). Accuracies of particle counts, compared with those of quantitative culture, were -8.5 and +2.8% for the two species, respectively. Electronic cell counts were highly linear between 5 X 10(6) and 5 X 10(4) CFU/ml (R2 greater than 0.99). Multiple electronic counts of a single suspension of C. albicans had less variation than did multiple quantitative cultures of a suspension of the same organism (coefficients of variation, 2.4 versus 8.9%; P less than 0.01), suggesting that impedance counting is probably more precise than quantitative culture. Electronic particle counters can be used to prepare accurate, reproducible yeast inocula. The method may be more accurate and is more precise than other techniques commonly used to standardize yeast suspensions.
Epidemic of Serratia marcescens bacteremia in a cardiac intensive care unit
Authors: Villarino M E , Jarvis W R , O'Hara C , Bresnahan J , Clark N
Published: January 2020

From 16 July through 27 September 1988, seven cases of nosocomial Serratia marcescens bacteremia occurred in a cardiac care unit. In all seven case patients, S. marcescens was isolated from blood cultures. Two of the seven had other microorganisms identified in the blood culture in which S. marcescens was recovered; one had Enterobacter cloacae, and one had Klebsiella pneumoniae. A case-control study was conducted to identify risk factors for bloodstream infection. Case patients were more likely than controls to have been exposed to an intra-aortic balloon pump pressure transducer (7 of 7 versus 6 of 21; P = 0.001) and to a pulmonary arterial pressure transducer (7 of 7 versus 8 of 21; P = 0.005). Cultures of in-use and in-storage transducers revealed bacterial contamination of the pressure-sensitive membranes of the transducers. S. marcescens blood culture isolates obtained from five of the seven case patients, as well as six S. marcescens isolates from cultured transducers, belonged to serotypes Oundetermined:H1 and Oundetermined:H18. E. cloacae isolates from one case patient and from two stored and two in-use transducers had identical antimicrobial suceptibility patterns. Review of cardiac care unit disinfection practices revealed that the transducers were not processed with high-level disinfection or sterilization between patient uses. We concluded that the transducers had served as reservoirs for this outbreak of bloodstream infection. Because intra-aortic balloon pumps with pressure transducers are being used more frequently in the management of critically ill cardiac patients, their role as infectious reservoirs should be considered in the investigation of nosocomial bacteremia.
Antibodies to staphylococcal DNases in sera from different animal species, including humans
Authors: Høie S , Fossum K
Published: January 2020

An agar diffusion method using microtiter plates was used to detect antibodies to the DNases produced by Staphylococcus aureus, S. intermedius, and S. hyicus. Antibodies to DNase from S. aureus were demonstrated in most of the sera from the species investigated, except dogs, only 11% of whose sera were positive. Positive titers to S. intermedius DNase were found in 84% of deg sera, 61% of Icelandic pony sera, 41% of pig sera, 21% of human sera, and 20% of cow sera but in only 2 and 4% of goat and sheep sera, respectively. Although antibodies to DNase from S. hyicus were not found in sera from humans, dogs, goats, or sheep, 84% of sera from pigs and cows and 29% of sera from Icelandic ponies were positive in this respect. The good accordance between the findings from bacteriological investigations performed elsewhere and the results of serologic tests performed in this study indicates that the results obtained with the serological method in this study properly reflect the actual antigenic exposure to and distribution of the three Staphylococcus spp. in animals and humans.
Development of a rapid diagnostic test for pertussis: direct detection of pertussis toxin in respiratory secretions
Authors: Friedman R L , Paulaitis S , McMillan J W
Published: January 2020

Monoclonal antibodies (MAb) were produced against the specific Bordetella pertussis antigen pertussis toxin (PT). In preliminary studies, one MAb (IB12) was selected and used in an enzyme-linked dot blot immunoassay to evaluate the ability of the method to detect known amounts of PT in control experiments and to test its potential for direct detection of PT in nasopharyngeal secretion (NP) specimens from patients with confirmed cases of whooping cough. The dot blot assay was able to detect PT at levels as low as 10 ng per dot in either buffer or control NP specimens. The assay demonstrated specificity, reacting only with dot blots of whole B. pertussis and not Bordetella bronchiseptica, Bordetella parapertussis, or other bacterial strains. In preliminary studies, NP aspirate, swab, and wash specimens were compared. The specimen of choice was found to be the NP aspirate, for which 100% positive results were found in the assay. These initial studies suggest that the dot blot immunoassay in which a MAb is used for direct detection of PT in NP specimens may be useful as a rapid diagnostic test for pertussis.
Investigation by improved syringe method of effect of tampons on production in vitro of toxic shock syndrome toxin 1 by Staphylococcus aureus
Authors: Wong A C , Downs S A
Published: January 2020

Twenty-seven types of commercial tampons from five manufacturers were tested in a sealed-syringe method to determine their effect on the growth of Staphylococcus aureus and the production of toxic shock syndrome toxin 1. In this improvement of the syringe method, the available air is limited to that which is contained within the sealed syringe containing the tampon. The culture medium was buffered, and blood and CO2 were included in the incubation to better simulate the vaginal environment during menstruation. Variables of tampon weight, composition, air volume, and absorbency were examined for their effect on the production of toxic shock syndrome toxin 1. Generally, with the exception of brand E, toxin production in the presence of tampons was equal to or lower than that in a sealed control syringe containing air but no tampon.
Detection of Mycoplasma pneumoniae by using the polymerase chain reaction
Authors: Bernet C , Garret M , de Barbeyrac B , Bebear C , Bonnet J
Published: January 2020

The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae. A specific DNA sequence for M. pneumoniae was selected from a genomic library, and two oligonucleotides were chosen in this sequence to give an amplified fragment of 144 base pairs. We show that DNA from different M. pneumoniae strains can be detected by PCR, with DNA from other Mycoplasma species giving negative results. Analysis of biological samples (throat swabs) obtained from hamsters that were experimentally infected with M. pneumoniae showed that PCR was more sensitive and reliable than conventional culture techniques for the detection of M. pneumoniae. Initial experiments on artificially seeded human bronchoalveolar lavages showed that PCR can be used to detect 10(2) to 10(3) organisms.
Use of plasmid analysis and determination of aminoglycoside-modifying enzymes to characterize isolates from an outbreak of methicillin-resistant Staphylococcus aureus
Authors: Licitra C M , Brooks R G , Terry P M , Shaw K J , Hare R S
Published: January 2020

We compared disk susceptibility, plasmid analysis, aminoglycoside resistance patterns, and DNA hybridization for their usefulness in characterizing isolates from a hospital outbreak of methicillin-resistant Staphylococcus aureus. Fifteen isolates were susceptible (group 1) and 28 were resistant (group 2) to gentamicin. A total of 15 of 15 (100%) group 1 and 22 of 28 (79%) group 2 isolates carried a 21.5-megadalton plasmid. All group 2 isolates and none of the group 1 isolates possessed a 33-megadalton plasmid. Aminoglycoside resistance pattern determinations revealed the presence of the ANT(4')-I enzyme (aminoglycoside 4' adenyltransferase) in all group 1 isolates but was unable to demonstrate presence of this enzyme in group 2 organisms. The APH(2") + AAC(6')-II enzyme (aminoglycoside 2" phosphotransferase plus 6' acetyltransferase) was found in all of the group 2 isolates but in none of the group 1 isolates. Use of DNA hybridization revealed the presence of the ANT(4')-I enzyme in both groups (group 1, 14 of 15; group 2, 26 of 28). In this hospital outbreak, we found good correlation between disk susceptibility, plasmid profile, aminoglycoside resistance patterns, and DNA hybridization results. It was difficult to predict the presence of the ANT(4')-I enzyme in the presence of the bifunctional [APH(2") + AAC(6')-II] enzyme by the aminoglycoside resistance pattern method because of overlap of the substrate profile.
Colonization of neonates in a nursery ward with enteropathogenic Escherichia coli and correlation to the clinical histories of the children
Authors: Senerwa D , Olsvik O , Mutanda L N , Gathuma J M , Wachsmuth K
Published: January 2020

Stool samples were examined from 30 preterm neonates admitted to a nursery ward; 16 neonates had diarrhea, 12 constituted an age-matched control group without diarrhea, and 2 had an unknown history regarding diarrhea. Variable numbers of enteropathogenic Escherichia coli serotype O111:HNT strains possessing the gene coding for the enteroadherence factor (EAF) were found in stool samples from 13 of the neonates. No other microbiological enteropathogen was found. A total of 294 strains (9 or 10 from each neonate, comprising 229 E. coli and 65 Klebsiella pneumoniae strains) were characterized with respect to plasmid content and grouped into 37 plasmid profile groups. Diarrhea was found not to be correlated with any specific plasmid profile or with the presence of the EAF-positive strains but rather with the number of strains with one specific plasmid profile or with the number of EAF-positive strains (of the 9 or 10 strains) isolated from each stool sample. All the neonates who died had diarrhea (5 died of 16 with diarrhea); all five of the neonates who died possessed strains with one specific plasmid profile group, and EAF-positive strains were isolated from four of them. Of the seven neonates from whom seven or more EAF-positive isolates were isolated, three died, compared with only one of five of those from whom only a few (1 to 3 of 10) EAF-positive strains were isolated. Both plasmid profiling and genetic probing with the EAF probe were found to be good alternatives when serotyping is not available for identification of O111:HNT enteropathogenic E. coli strains.
Interactions of CD4+ and CD8+ human T lymphocytes from malaria-unprimed donors with Plasmodium falciparum schizont stage
Authors: Roussilhon C , Agrapart M , Behr C , Dubois P , Ballet J J
Published: January 2020

During Plasmodium falciparum malaria, a wide spectrum of parasite-encoded blood-stage proteins is presented to the immune system of the host. To explore their multiple interactions with T cells from donors who have had no previous exposure to the parasite, whole schizont extract was used in vitro. Both CD4+ and CD8+ lymphocytes from all individuals tested were stimulated to proliferate. The responses were dependent on the presence of accessory cells and were only partially replaced by recombinant interleukin-1. Responses were inhibited by monoclonal antibodies to CD3, the alpha beta-chain T-cell receptor, or CD4 molecules but not to CD2. P. falciparum schizont extract-specific T-cell clones were generated and maintained by using sole stimulation by P. falciparum extract with autologous accessory cells or recombinant interleukin-2. Monoclonal antibodies to CD3 (or the alpha beta-chain T-cell receptor) blocked cloned T-cell responses to the schizont extract, and although the responses of the majority of the CD4+ or CD8+ T-cell clones were restricted by autologous accessory cells and inhibited by monoclonal antibodies to either CD4 or CD8, other clones responded to P. falciparum in the absence of accessory cells and were not regulated by the same monoclonal antibodies. The last category of clones consisted of autoreactive T cells. These data suggest that at the first contact with P. falciparum, requirements are met for significant T-cell stimulation.
Rapid detection of gastric Campylobacter pylori colonization by a simple biochemical test
Authors: Abdalla S , Marco F , Perez R M , Piqué J M , Bordas J M , Jimenez de Anta M T , Teres J
Published: January 2020

A simple and rapid urease test to detect Campylobacter pylori infection was evaluated with bacterial culture as the "gold standard." The test was compared with the Gram stain and the conventional Christensen urease test. The culture method detected C. pylori in 29 of 49 gastric biopsy specimens. The rapid urease test showed 27 positive samples within 1 h at 55 degrees C (specificity, 100%; sensitivity, 93%) and 18 at room temperature (specificity, 100%; sensitivity, 62%). The Gram stain exhibited a sensitivity of 86% and a specificity of 91%. The conventional Christensen urease test detected C. pylori in only 4, 10, and 18 samples after 24, 48, and 72 h, respectively (sensitivities, 12, 36, and 60%, respectively; specificities, 95, 95, and 83%, respectively). We conclude that the rapid urease test is simple and highly specific for the detection of C. pylori and that it can be performed with small amounts of sample.
Differentiation of primary from nonprimary genital herpesvirus infections by detection of polymeric immunoglobulin A activity
Authors: Hashido M , Kawana T , Inouye S
Published: January 2020

We analyzed antibody responses to herpes simplex virus (HSV) in 18 patients by using sucrose gradient centrifugation and an enzyme-linked immunosorbent assay for antibody determination. We found that the HSV-specific immunoglobulin A (IgA) antibody in early-convalescent-phase serum specimens from all of 8 primary cases consisted solely of polymeric forms, whereas in all 10 nonprimary cases, the major component was monomeric. These results indicate that the ratio of polymeric IgA to monomeric IgA antibody activity may be useful for differentiating primary from nonprimary HSV infections.
Staining bacterial flagella easily
Authors: Heimbrook M E , Wang W L , Campbell G
Published: January 2020

A wet-mount technique for staining bacterial flagella is highly successful when a stable stain and regular slides and cover slips are used. Although not producing a permanent mount, the technique is simple for routine use when the number and arrangement of flagella are critical in identifying species of motile bacteria.
Pseudomonas aeruginosa ATCC 49189, a new quality control strain for testing P. aeruginosa susceptibility to the aminoglycosides
Authors: Lally R T , Woolfrey B F , Enright M A
Published: January 2020

Quality control for in vitro antimicrobial susceptibility testing of Pseudomonas aeruginosa versus aminoglycosides is improved by P. aeruginosa ATCC 49189, which was developed in the Clinical Microbiology Laboratory at St. Paul-Ramsey Medical Center. This strain, used by us for daily testing for the past 6 years, requires MICs that approximate therapeutic concentrations, are midrange in most dilution schemes, and are stable and reproducible.
Evaluation of trehalose-mannitol broth for differentiation of Staphylococcus epidermidis from other coagulase-negative staphylococcal species
Authors: Knapp C C , Washington J A
Published: January 2020

Trehalose-mannitol agar and various broth formulations thereof were evaluated for the differentiation of Staphylococcus epidermidis from other common coagulase-negative staphylococcal species isolated from human blood cultures. While this differentiation was accurately made on trehalose-mannitol agar in 18 h, modification of the medium to a broth formulation containing 2% each trehalose and mannitol in 0.2 ml of purple broth base provided greater than 95% accuracy when a heavy inoculum was incubated on a rotary shaker for at least 4 h.
Polymerase chain reaction assay of parvovirus B19 DNA in clinical specimens
Authors: Clewley J P
Published: January 2020

The polymerase chain reaction (PCR) was used to detect parvovirus B19 DNA in a panel of sera from individuals recently infected with B19, as demonstrated by the presence of anti-B19 immunoglobulin M. Of 95 serum samples, 60 (63%) were found positive by PCR, whereas only 1 was also found positive by dot hybridization. In a control panel of 100 serum samples from individuals with other infections, only 1 serum sample was found positive by PCR, and this was also found positive by dot hybridization. This was probably just a fortuitous discovery of viremia. Placental tissues from women (n = 89) who had proven B19 infections in pregnancy but who gave birth to healthy infants at term were also tested. A total of 74 (83%) were found positive for B19 DNA by PCR. The high rate of detection by PCR probably represents "decay" of viral DNA after the peak of viremia and is not a clinically significant phenomenon.
Amplification of human papillomavirus DNA sequences by using conserved primers
Authors: Gregoire L , Arella M , Campione-Piccardo J , Lancaster W D
Published: January 2020

The polymerase chain reaction has potential for use in the detection of small amounts of human papillomavirus (HPV) viral nucleic acids present in clinical specimens. However, new HPV types for which no probes exist would remain undetected by using type-specific primers for the polymerase chain reaction before hybridization. Primers corresponding to highly conserved HPV sequences may be useful for detecting low amounts of known HPV DNA as well as new HPV types. Here we analyze a pair of primers derived from conserved sequences within the E1 open reading frame for HPV sequence amplification by using the polymerase chain reaction. The longest perfect homology among HPV sequences is a 12-mer within the first exon of E1M. A region of conserved amino acids coded by the E1 open reading frame allowed the detection of another highly conserved region about 850 base pairs downstream. Two 21-mers derived from these conserved regions were used to amplify sequences from all HPV DNAs used as templates. The amplified DNA was shown to be specific for HPV sequences within the E1 open reading frame. DNA from HPVs whose sequences were not available were amplified by using these two primers. HPV DNA sequences in clinical specimens could also be amplified with the primers.
Clonal diversity and relationships among strains of Yersinia enterocolitica
Authors: Caugant D A , Aleksic S , Mollaret H H , Selander R K , Kapperud G
Published: January 2020

Allelic variation in the chromosomal genome of 81 isolates of Yersinia enterocolitica and single isolates of Yersinia intermedia, Yersinia frederiksenii, Yersinia mollaretii, and Yersinia kristensenii was assessed by analysis of electrophoretically demonstrable polymorphism in 21 genes encoding metabolic enzymes. Eighteen distinctive multilocus genotypes (electrophoretic types [ETs]) were identified. Clustering of the ETs from a matrix of pairwise genetic distances, based on the 21 enzyme loci, confirmed the genetic distinctness of serogroup 3 isolates of Y. intermedia, Y. frederiksenii, Y. mollaretii, and Y. kristensenii and identified another serogroup 3 isolate that was also not a member of Y. enterocolitica. The 13 ETs of Y. enterocolitica clustered into two groups: cluster A, which included eight ETs represented by isolates of serogroups 1; 2; 3; 5,27; and 9, and cluster B, which included four ETs represented by isolates of serogroups 8, 13, and 21. Clones of cluster A were found to be distributed worldwide, but those of cluster B were largely restricted to North America. Isolates of genotypes belonging to cluster B were lethal to mice, whereas those of cluster A were not, suggesting an influence of the chromosomal background on the virulence of Y. enterocolitica.
Use of Shigella flexneri ipaC and ipaH gene sequences for the general identification of Shigella spp. and enteroinvasive Escherichia coli
Authors: Venkatesan M M , Buysse J M , Kopecko D J
Published: January 2020

The products of the ipaB, ipaC, and ipaD genes are involved in the expression of the invasive phenotype in all species of Shigella and enteroinvasive Escherichia coli (EIEC). DNA probes derived from these genes are accurate indicators of the invasive phenotype (M. Venkatesan, J. M. Buysse, E. V. Vandendries, and D. J. Kopecko, J. Clin. Microbiol. 26:261-266, 1988); however, spontaneous loss of the invasion plasmid or selective deletion of invasion-associated genes may restrict the usefulness of such probes as general diagnostic tools. In this study, we report that laboratory-passaged strains of Shigella spp. and EIEC that were invasion and Sereny test negative were unable to hybridize to the ipaC DNA probe. However, a second DNA probe, derived from the Shigella flexneri ipaH gene, a multiple-copy element found on the chromosome and invasion plasmid that encodes a 60-kilodalton antigen, was more sensitive in its ability to detect virulent as well as avirulent shigellae and EIEC. Analysis of colony blots and stool blots from pediatric patients with diarrhea indicated that the ipaH probe was more effective in detecting shigellae and EIEC than was either the ipaC or 17-kilobase EcoRI fragment probe.
O-antigen specificities of the serotype strains of Serratia marcescens
Authors: Gaston M A , Pitt T L
Published: January 2020

O antigens of the 24 O-serotype strains of Serratia marcescens were investigated in dot enzyme immunoassay with whole-cell antigens and by immunoblotting with lipopolysaccharide (LPS) antigens. Three pairs of strains, O2/O3, O6/O7, and O12/O14, had indistinguishable LPS antigens, despite having distinct specificities in agglutination tests with whole-cell antigens. Strong cross-reactions were also found in LPS antigens from strains O9/O15, O17/O19, O10/O22, and O16/O20. No high-molecular-weight LPS corresponding to O-side-chain material was detected in strain O11 or O13. A panel of absorbed antisera was prepared to facilitate the detection of a reduced set of LPS antigens in a dot enzyme immunoassay. We conclude that there are discrepancies between the existing serotypes as defined by agglutination tests and the antigenic composition of LPS antigens extracted from the serotype strains and that surface antigens other than LPS make a major contribution to the definition of serotype in the species.
Acinetobacter baumannii serotyping for delineation of outbreaks of nosocomial cross-infection
Authors: Traub W H
Published: January 2020

A total of 152 clinical isolates of Acinetobacter baumannii from 152 patients were identified by carbon source utilization tests and examined serologically. Polyclonal rabbit immune sera against A. baumannii strains were used in checkerboard tube agglutination tests, and 20 serovars were identified. One (serovar 19) cross-reacted with genospecies 3 (serovar 3), a closely related member of the genus Acinetobacter. Several outbreaks of nosocomial cross-infection caused by serovars 4 and 10 were delineated.
Comparison of the nasal bacterial floras in two groups of healthy subjects and in patients with acute maxillary sinusitis
Authors: Jousimies-Somer H R , Savolainen S , Ylikoski J S
Published: January 2020

The nasal bacterial flora was studied in 183 healthy men entering military service (entry group), 103 healthy recruits in service (service group), and 185 recruits with acute maxillary sinusitis. The 267 nasal and ipsilateral sinus aspirate findings in the same patients with acute maxillary sinusitis were compared pairwise. In the entry group presumed sinus pathogens were only rarely isolated from the nasal cavities: Haemophilus influenzae in 4%, Streptococcus pneumoniae in 1%, Branhamella catarrhalis in 3%, and Streptococcus pyogenes in 0%. The corresponding isolation frequencies in the service group were 19, 13, 3, and less than 1%, respectively, and those in the group with acute maxillary sinusitis were 61, 25, 7, and 6%, respectively. Suppression of the major components of the normal nasal flora, Corynebacterium sp., coagulase-negative staphylococci, Propionibacterium acnes, and Staphylococcus aureus, was seen in the group with acute maxillary sinusitis and also occasionally in the service group. When a sinus aspirate culture yielded a presumed sinus pathogen, the same pathogen was found in the nasal samples in 91% of the cases. The predictive value of a pathogen-positive nasal finding was highest (93.8%) for S. pyogenes, followed by 77.7% for H. influenzae and 68.7% for S. pneumoniae, and lowest (20%) for B. catarrhalis.
Reactivity of VP4-specific monoclonal antibodies to a serotype 4 porcine rotavirus with distinct serotypes of human (symptomatic and asymptomatic) and animal rotaviruses
Authors: Kang S Y , Saif L J , Miller K L
Published: January 2020

Thirteen hybridomas secreting VP4-specific monoclonal antibodies against the Gottfried strain of porcine rotavirus (serotype 4) were produced and characterized. Nine of the hybridomas secreted neutralizing monoclonal antibodies (N-MAbs) against Gottfried rotavirus. These N-MAbs were divided into five distinct groups (groups I to V) according to their patterns of reactivity with different serotypes of human and animal rotaviruses. Group I N-MAbs (n = 3) were cross-reactive with five different serotypes of human rotavirus examined by a plaque reduction virus neutralization test. Group II N-MAbs (n = 3) neutralized all symptomatic human rotavirus serotypes tested and asymptomatic human rotavirus serotype 4 to a low titer. The single group III N-MAb neutralized mainly symptomatic human rotavirus serotypes 2 and 9 and none of the asymptomatic human rotavirus serotypes. The one N-MAb in group IV reacted at low titers with only asymptomatic human rotavirus serotypes 1 through 4. A group V N-MAb recognized serotype 4 porcine rotaviruses (Gottfried and SB-2) but no other human or animal rotaviruses examined. None of the N-MAbs recognized any animal rotaviruses tested (SA-11, RRV, OSU, NCDV, and B223), except for the Gottfried and SB-2 rotaviruses. The failure of N-MAbs (groups I to IV) to react with any animal rotaviruses tested but their ability to react variably with all human rotaviruses tested suggest that neutralizing epitopes on the VP4 protein are highly conserved between the Gottfried porcine and human rotaviruses. The Gottfried rotavirus may possibly represent a naturally occurring reassortant between pig and human rotaviruses or a rotavirus which is human in origin but pathogenic for swine.
Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline
Authors: Jones R N , Gavan T L , Thornsberry C , Fuchs P C , Gerlach E H , Knapp J S , Murray P , Washington J A
Published: January 2020

A six-laboratory study developed a standardized method for determining the susceptibilities of Neisseria gonorrhoeae strains to penicillin, tetracycline, spectinomycin, and ceftriaxone. Three quality control organisms were also selected, and quality assurance guidelines were initially generated for the disk diffusion and agar dilution methods. The medium recommended for gonococcal susceptibility testing was GC agar with a defined "XV-like" supplement. The supplement should be free of cysteine, a component implicated in the inactivation of some newer beta-lactam compounds. Penicillin, tetracycline, spectinomycin, and ceftriaxone were stable in agar plates stored at 3 to 5 degrees C for at least 2 weeks. Numerous GC agar and drug disk lots were used during the trials without significant variation in test results. Several other gonococcal strains were recommended for additional medium quality assurance. The disk quality control zone limits were established for N. gonorrhoeae ATCC 49226 (formerly CDC F-18) and Staphylococcus aureus ATCC 25923. MIC quality control ranges were also developed for N. gonorrhoeae ATCC 49226 and S. aureus ATCC 29213. The interpretive criteria for penicillin were as follows: susceptibility, greater than or equal to 47 mm (diameter of inhibition zone) (less than or equal to 0.06 micrograms/ml [MIC]); resistance, less than or equal to 26 mm (greater than or equal to 2 micrograms/ml). For tetracycline they were as follows: susceptibility, greater than or equal to 38 mm (less than or equal to 0.25 microgram/ml); resistance, less than or equal to 30 mm (greater than or equal to 2 micrograms/ml). For spectinomycin they were as follows: susceptibility, >/= 18 mm (</= 32 micrograms/ml); resistance, </= 14 mm (>/= 128 micrograms/ml). For ceftriaxone susceptibility, the criterion was >/= 35 mm (</= 0.25 micrograms/ml) with no other category. Criteria of </= 19 mm for plasmid-mediated resistances to penicillin and tetracycline were also confirmed. The false-susceptibility errors were </= 1% with these criteria.
Enzyme immunoassay to determine exposure to Chlamydia pneumoniae (strain TWAR)
Authors: Ladany S , Black C M , Farshy C E , Ossewaarde J M , Barnes R C
Published: January 2020

Recent studies suggest that a group of Chlamydia strains known as TWAR, which are now proposed to be a new species called Chlamydia pneumoniae, may be a frequent cause of respiratory disease in the United States and many other countries. Current serotesting methods do not allow rapid screening of large numbers of samples to distinguish C. trachomatis exposure from C. pneumoniae exposure. We developed an enzyme immunoassay to decrease cross-reactivity between immunoglobulin G antibodies reactive with C. trachomatis and C. pneumoniae. Elementary bodies of C. trachomatis or C. pneumoniae were treated with a detergent-chelating solution to decrease the reactivity of the common lipopolysaccharide antigens. Sera from four groups of patients, totaling 143 persons, were tested by this assay. The prevalences of titers of greater than or equal to 128 to C. trachomatis and C. pneumoniae, respectively, were as follows: (i) for 23 women seropositive for C. trachomatis by the microimmunofluorescence test, 21 (91%) and 18 (78%); (ii) for 50 adult blood donors, 13 (26%) and 39 (78%); (iii) for 40 sexually transmitted disease clinic patients, 20 (50%) and 32 (80%); (iv) for 30 healthy children 5 to 7 years old, 0 (0%) and 8 (27%). Western blots (immunoblots) of each antigen corroborated the differential reactivity of C. trachomatis-positive, C. pneumoniae-negative and C. trachomatis-negative, C. pneumoniae-positive serum samples. Western blots of serum samples from rabbits immunized with either C. trachomatis or C. pneumoniae elementary bodies revealed at least two protein bands (30 and 80 kilodaltons) which appeared to represent unique C. pneumoniae antigens.
Pseudomonas aeruginosa flagellar antibodies in patients with cystic fibrosis
Authors: Anderson T R , Montie T C , Murphy M D , McCarthy V P
Published: January 2020

An enzyme-linked immunosorbent assay specific for flagellum type (a or b) of Pseudomonas aeruginosa was used to detect serum immunoglobulin antibodies in 98 random outpatients and 14 colonized cystic fibrosis patients. Antibodies were detected to both types of flagella in addition to M-2 lipopolysaccharide. Titers to both flagellar antigens (FlAg) were 10 to 100 times higher in cystic fibrosis patients than in random outpatients of a comparable age group. Mean antibody titers against b-type FlAg were 454 for outpatients (ages newborn to 21 years), whereas the mean titer for cystic fibrosis patients (ages 6 to 21 years) was 51,520. Titers against a-type FlAg were generally lower, with mean outpatient titers of 68 and mean cystic fibrosis patient titers of 34,323. Differences were also seen in antibody titer against M-2 lipopolysaccharide, but these differences did not correspond to M-2 FlAg titers. In 98 random outpatients (ages newborn to 86 years), FlAg titers generally increased with age. To demonstrate further specificity of the enzyme-linked immunosorbent assay for flagellum antibody, Western blots were performed with selected high-titer cystic fibrosis patient sera. Sera that had a high titer (greater than 25,600) for b- or a-type FlAg showed a corresponding reactive band. These results demonstrate that flagellum antibodies are produced in humans in response to P. aeruginosa infection.
Comparison of immunoglobulin A (IgA), IgG, and IgM enzyme-linked immunosorbent assays, plaque reduction neutralization assay, and complement fixation in detecting seroresponses to rotavirus vaccine candidates
Authors: Midthun K , Pang L Z , Flores J , Kapikian A Z
Published: January 2020

In a phase 1 study to evaluate human-rhesus rotavirus reassortant vaccines, 116 infants 1 to 5 months of age received one of the following five preparations: the serotype 1 reassortant, the serotype 2 reassortant, rhesus rotavirus (serotype 3), a bivalent preparation (serotypes 1 and 3), or a placebo. Seroresponses to the different vaccines were measured by plaque reduction neutralization assay (PRNA); rotavirus-specific immunoglobulin A (IgA), IgG, and IgM enzyme-linked immunosorbent assays (ELISAs); and complement fixation (CF). The seroresponse rate, calculated by using a fourfold or greater antibody rise by any assay, was similar in the four vaccine groups (83 to 96%). When the data from all the vaccinees were pooled, IgA ELISA, IgG ELISA, and PRNA were comparable in detecting seroresponses (67, 62, and 70%, respectively) and more efficient than IgM ELISA (53%) and CF (44%). When the vaccinees were analyzed by age, the overall seroresponse rates were the same for infants 1 to 2 and 3 to 5 months old (90%). The IgA ELISA and PRNA were the most efficient for detecting antibody rises in both age groups. IgG ELISA was among the least efficient methods for detecting antibody rises in the younger age group but among the most efficient in the older age group (44 versus 78%). CF was among the least efficient methods in both age groups but was significantly better in the older age group than in the younger age group (54 versus 21%). Our findings show that ELISA, in particular rotavirus-specific IgA ELISA, is a sensitive indicator of vaccine takes in 1- to 5 month-old infants, the target population for vaccination. ELISA should also be very useful in demonstrating natural rotavirus infections in field studies in which a stool specimen from a diarrheal episode is not always available. The ELISA has the advantages of being easier and quicker and requiring less serum than PRNA, but it does not give serotype-specific information about the immune response.
Gas chromatographic assessment of alcoholyzed fatty acids from yeasts: a new chemotaxonomic method
Authors: Brondz I , Olsen I , Sjöström M
Published: January 2020

An alternative chemotaxonomic method to methanolysis was developed for gas chromatographic assessment of fatty acids in whole yeast cells. Clinical and reference strains of the medically important yeasts Candida albicans, Torulopsis glabrata, and Saccharomyces cerevisiae were cultured for 48 h at 26 degrees C. Cellular lysis and transesterification were then performed with ethanol, propanol, butanol, or methanol. The relative recovery rates for cellular fatty acids, including the volatile acids C10:0 and C12:0, were similar after alcoholysis with ethanol, propanol, or butanol, while methanolysis gave lower recoveries of volatile fatty acids. Thus, after ethanolysis, the recovery of C10:0 acid (0.1, 1, and 10%) from a defined matrix (lyophilized Actinobacillus actinomycetemcomitans cells) varied from 97 to 102%, while the recovery of C10:0 after methanolysis varied from 49 to 75%. This indicated that with the frequently used methanolysis technique, there is a considerable loss of volatile fatty acids. These acids may be used as marker molecules for taxonomic differentiation between yeasts.
Urease-positive, Kanagawa-negative Vibrio parahaemolyticus from patients and the environment in the Pacific Northwest
Authors: Kelly M T , Stroh E M
Published: January 2020

We previously reported the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. The present studies compare the biochemical characteristics, Kanagawa hemolysin reactions, and plasmid profiles of 13 patient and 221 environmental isolates of the organism. Classical biochemical testing of the isolates revealed similar reactions for the clinical and environmental strains, and analysis in agarose gels revealed that 13 to 15% of the isolates had plasmids. The strains were tested for production of Kanagawa hemolysin on Wagatsuma agar, and 1.4% of environmental isolates and 23% of clinical isolates were positive. Clinical isolates from locally acquired extraintestinal infections were urease negative and Kanagawa hemolysin negative, isolates from locally acquired gastroenteritis cases were urease positive and Kanagawa negative, and isolates from traveler's diarrhea were urease negative and Kanagawa positive. Eight percent of the local environmental isolates were also urease positive and Kanagawa hemolysin negative. These findings suggest that expression of the Kanagawa hemolysin is not essential for the pathogenesis of V. parahaemolyticus infections. In addition, our findings suggest that V. parahaemolyticus gastroenteritis in the Pacific Northwest is associated with a urease-positive, Kanagawa-negative biotype of the organism.
Unusual non-serogroup O1 Vibrio cholerae bacteremia associated with liver disease
Authors: Dhar R , Ghafoor M A , Nasralah A Y
Published: January 2020

A 50-year-old woman and a 31-year-old man with underlying liver disease presented with fever and signs of liver failure. The blood cultures in both cases yielded non-serogroup O1 Vibrio cholerae strains which were biochemically identical except that one strain was nonmotile. Despite treatment with antibiotics, the older patient died; the other patient survived. Both strains were found to be susceptible to most antibiotics tested in vitro. No apparent source of infection could be identified in either case.
Bacteremic cellulitis caused by non-serogroup O1 Vibrio cholerae acquired in a freshwater inland lake
Authors: Pitrak D L , Gindorf J D
Published: January 2020

The number of reported cases of infections with non-serogroup O1 Vibrio cholerae in the United States has increased recently. These cases have almost invariably been associated with travel, seawater exposure, or the ingestion of shellfish. We report a case of bacteremic cellulitis caused by non-O1 V. cholerae that was acquired in a freshwater inland lake in northern Illinois. The organism is more widely distributed than generally appreciated, and the potential for infection in patients without the usual risk factors exists.
Urinary tract infection caused by Enterobacter taylorae
Authors: Reina J , Salva F , Gil J , Alomar P
Published: January 2020

We present a case of urinary tract infection caused by Enterobacter taylorae in a 70-year-old male with renal lithiasis. The microorganism was isolated in significant numbers from a urine culture. The disappearance of clinical symptoms after antibiotic treatment points to the participation of this microorganism as the etiological agent in the infection.
Evaluation of a latex particle agglutination assay for the detection of cytomegalovirus antibody in patient serum
Authors: Hursh D A , Abbot A D , Sun R , Iltis J P , Rice D H , Gleaves C A
Published: January 2020

The Virogen CMV Antibody Test is a simple and rapid latex agglutination assay for the detection of cytomegalovirus antibody in human serum and plasma. Evaluation of this assay with respect to enzyme immunoassay yielded a sensitivity of 98% with a specificity of 100%. In comparison to CMVScan, the Virogen CMV Antibody Test had a sensitivity of 98.4% and a specificity of 100%.