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Molecular Epidemiology of Pulmonary Tuberculosis in Belgrade, Central Serbia

Vuković, Dragana; Rüsch-Gerdes, Sabine; Savić, Branislava; Niemann, Stefan
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2003 EN
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36.23%
In order to gain precise data on the actual epidemiology of tuberculosis (TB) in Belgrade, central Serbia, we conducted the molecular epidemiological investigation described herein. IS6110 restriction fragment length polymorphism (RFLP) typing of 176 Mycobacterium tuberculosis isolates was performed. These strains were obtained from 48.4% of all patients diagnosed with culture-proven pulmonary TB from April through September 1998 and from May through October 1999. Clusters containing strains with identical RFLP IS6110 patterns were assumed to have arisen from recent transmission. Of the 176 cases, 55 (31.2%) were grouped into 23 clusters ranging in size from two to six patients. Nearly 80% of clustered patients were directly interviewed, and transmission between family-unrelated contacts was found to be predominant in the study population. Classical contact investigation identified only 2 (3.6%) of the 55 clustered patients. The clustering of TB patients was not associated with any demographic or clinical characteristic other than infection with multidrug-resistant (MDR) M. tuberculosis strains. Nearly 70% of MDR strains were clustered, which indicates active transmission of MDR TB in Belgrade. However, this was not observed by conventional epidemiologic surveillance. In conclusion...

Epidemiology and Molecular Characterization of Clostridium difficile Strains from Patients with Diarrhea: Low Disease Incidence and Evidence of Limited Cross-Infection in a Swedish Teaching Hospital

Svenungsson, Bo; Burman, Lars G.; Jalakas-Pörnull, Kirsti; Lagergren, Åsa; Struwe, Johan; Åkerlund, Thomas
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2003 EN
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36.23%
We prospectively studied the epidemiology of Clostridium difficile-associated diarrhea (CDAD) in a 900-bed hospital over the course of 12 months by PCR-ribotyping of C. difficile isolates. A total of 304 cases were diagnosed, corresponding to an overall incidence of 7/1,000 admissions, with higher rates in nephrology, hematology, and organ transplantation wards (37, 30, and 21/1,000), and 72% were classified as hospital associated (onset in hospital or onset at home but after a hospital stay within 2 months). All 382 isolates from 227 of 304 (75%) patients available for PCR-ribotyping were typeable, yielding 70 PCR-ribotypes. The three most common types comprised 30% of hospital-associated and 34% of community-associated cases, indicating import via admitted patients as a major source of C. difficile strains occurring in the hospital. Of the 227 patients studied, 38% each contributed 2 to 13 fecal samples positive for C. difficile over the course of the study period. Repeat isolates of the same PCR-ribotype as the first isolate were found in 79% of these patients and in 95% of specimens delivered within 30 days, compared to 63% of those obtained at 31 to 204 days. Nosocomial acquisition of CDAD, defined as the proportion of cases sharing C. difficile type and admitted to the same ward within 2 or 12 months...

Prevalence, Molecular Epidemiology, and Clinical Significance of Heterogeneous Glycopeptide-Intermediate Staphylococcus aureus in Liver Transplant Recipients

Bert, Frédéric; Clarissou, Juliette; Durand, François; Delefosse, Didier; Chauvet, Chantal; Lefebvre, Patricia; Lambert, Nicole; Branger, Catherine
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /11/2003 EN
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We investigated the prevalence, molecular epidemiology, and clinical significance of heterogeneous glycopeptide-intermediate Staphylococcus aureus (hGISA) isolates in 48 liver transplant recipients infected or colonized with methicillin-resistant S. aureus over a 5-year period. Strains were screened for hGISA on Mueller-Hinton agar containing 5 mg of teicoplanin per liter. Heterogeneous glycopeptide resistance was confirmed by the E-test method with a dense inoculum and a simplified method of population analysis. hGISA strains were found in 13 (27%) of the 48 patients studied. Eleven of the 13 strains shared a common multiresistant phenotype with homogeneous methicillin resistance and gentamicin resistance, and they were closely related according to the results of pulsed-field gel electrophoresis. Only 2 of the 13 patients infected or colonized with hGISA strains had previously received glycopeptide therapy. Most patients were successfully treated with vancomycin, but one patient who failed to respond to vancomycin subsequently died. These results suggest that the high prevalence of hGISA among our patients was due to the clonal spread of a multiresistant strain.

Molecular Epidemiology of Sequential Outbreaks of Acinetobacter baumannii in an Intensive Care Unit Shows the Emergence of Carbapenem Resistance

Zarrilli, Raffaele; Crispino, Margherita; Bagattini, Maria; Barretta, Elena; Di Popolo, Anna; Triassi, Maria; Villari, Paolo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2004 EN
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The molecular epidemiology of multidrug-resistant Acinetobacter baumannii was investigated in the medical-surgical intensive care unit (ICU) of a university hospital in Italy during two window periods in which two sequential A. baumannii epidemics occurred. Genotype analysis by pulsed-field gel electrophoresis (PFGE) of A. baumannii isolates from 131 patients identified nine distinct PFGE patterns. Of these, PFGE clones B and I predominated and occurred sequentially during the two epidemics. A. baumannii epidemic clones showed a multidrug-resistant antibiotype, being clone B resistant to all antimicrobials tested except the carbapenems and clone I resistant to all antimicrobials except ampicillin-sulbactam and gentamicin. Type 1 integrons of 2.5 and 2.2 kb were amplified from the chromosomal DNA of epidemic PFGE clones B and I, respectively, but not from the chromosomal DNA of the nonepidemic clones. Nucleotide analysis of clone B integron identified four gene cassettes: aacC1, which confers resistance to gentamicin; two open reading frames (ORFs) coding for unknown products; and aadA1a, which confers resistance to spectinomycin and streptomycin. The integron of clone I contained three gene cassettes: aacA4, which confers resistance to amikacin...

Study of Molecular Epidemiology of Candidiasis in Portugal by PCR Fingerprinting of Candida Clinical Isolates

Correia, Alexandra; Sampaio, Paula; Pais, Judite Almeida and Célia
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/2004 EN
Relevância na Pesquisa
36.23%
PCR fingerprinting was used to type 177 yeast isolates obtained from two medical institutions. Candida albicans was the predominant species found, followed by C. tropicalis, C. glabrata, C. parapsilosis, C. guilliermondii, and C. krusei, which accounted for over 20% of the strains isolated. This survey represents the first study of molecular epidemiology of candidiasis in Portugal.

Molecular Epidemiology of Respiratory Syncytial Virus Infections among Children with Acute Respiratory Symptoms in a Community over Three Seasons

Sato, Mizuho; Saito, Reiko; Sakai, Takatsugu; Sano, Yasuko; Nishikawa, Makoto; Sasaki, Asami; Shobugawa, Yugo; Gejyo, Fumitake; Suzuki, Hiroshi
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2005 EN
Relevância na Pesquisa
36.23%
To study the molecular epidemiology of respiratory syncytial virus (RSV) in a community, children with acute respiratory symptoms at a pediatric outpatient clinic in Niigata, Japan, were analyzed over three seasons from November 2001 to July 2004. Of 499 nasopharyngeal aspirate specimens, 185 (37.1%) were RSV positive, and only 8 (4.5%) of 177 patients were shown by the reverse transcription (RT)-PCR method to be reinfected. RSV infection occurred beginning in the early winter, and the rates declined in the spring. The predominant subgroup changed from A to B and returned to A over the three seasons. Phylogenetic analysis also revealed that multiple genotypes cocirculated each year, with genotype GA5 of subgroup A predominating in the 2001-2002 and the 2003-2004 seasons. A new genotype of subgroup B (named BA, according to the nomenclature for viruses) with a 60-nucleotide insertion in the second variable region of the attachment glycoportein protein was predominant as an emerging strain in the 2002-2003 season, but this was not associated with new epidemiological or clinical features, unlike the cases of disease caused by other genotypes in the other seasons. In conclusion, our molecular analysis of RSV confirms that multiple genotypes cocirculate each year and that the genotype predominating may shift with the season. Support for determination of the genotype by RT-PCR as an effective tool for characterization of RSV circulation patterns in the community is provided.

Sensitivities and Specificities of Spoligotyping and Mycobacterial Interspersed Repetitive Unit-Variable-Number Tandem Repeat Typing Methods for Studying Molecular Epidemiology of Tuberculosis

Scott, Allison N.; Menzies, Dick; Tannenbaum, Terry-Nan; Thibert, Louise; Kozak, Robert; Joseph, Lawrence; Schwartzman, Kevin; Behr, Marcel A.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2005 EN
Relevância na Pesquisa
36.23%
The development of PCR-based genotyping modalities (spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem repeat [MIRU-VNTR] typing) offers promise for real-time molecular epidemiological studies of tuberculosis (TB). However, the utility of these methods depends on their capacity to appropriately classify isolates. To determine the operating parameters of spoligotyping and MIRU-VNTR typing, we have compared results generated by these newer tests to the standard typing method, IS6110 restriction fragment length polymorphism, in analyses restricted to high-copy-number IS6110 isolates. Sensitivities of the newer tests were estimated as the percentages of isolates with identical IS6110 fingerprints that had identical spoligotypes and MIRU-VNTR types. The specificities of these tests were estimated as the percentages of isolates with unique IS6110 fingerprints that had unique spoligotypes and MIRU-VNTR types. The sensitivity of MIRU-VNTR typing was 52% (95% confidence interval [CI], 31 to 72%), and the sensitivity of spoligotyping was 83% (95% CI, 63 to 95%). The specificity of MIRU-VNTR typing was 56% (95% CI, 51 to 62%), and the specificity of spoligotyping was 40% (95% CI, 35 to 46%). The proportion of isolates estimated to be due to recent transmission was 4% by identical IS6110 patterns...

Molecular Epidemiology of Pneumococcal Colonization in Response to Pneumococcal Conjugate Vaccination in Children with Recurrent Acute Otitis Media

Bogaert, D.; Veenhoven, R. H.; Sluijter, M.; Wannet, W. J. W.; Rijkers, G. T.; Mitchell, T. J.; Clarke, S. C.; Goessens, W. H. F.; Schilder, A. G.; Sanders, E. A. M.; de Groot, R.; Hermans, P. W. M.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2005 EN
Relevância na Pesquisa
36.23%
A randomized double-blind trial with a 7-valent pneumococcal conjugate vaccine was conducted in The Netherlands among 383 children, aged 1 to 7 years, with a history of recurrent acute otitis media. No effect of vaccination on the pneumococcal colonization rate was found. However, a shift in serotype distribution was clearly observed (R. Veenhoven et al., Lancet 361:2189-2195, 2003). We investigated the molecular epidemiology of 921 pneumococcal isolates retrieved from both the pneumococcal vaccine (PV) and control vaccine (CV) groups during the vaccination study. Within individuals a high turnover rate of pneumococcal restriction fragment end labeling genotypes, which was unaffected by vaccination, was observed. Comparison of the genetic structures before and after completion of the vaccination scheme revealed that, despite a shift in serotypes, there was clustering of 70% of the pneumococcal populations. The remaining isolates (30%) were equally observed in the PV and CV groups. In addition, the degree of genetic clustering was unaffected by vaccination. However, within the population genetic structure, nonvaccine serotype clusters with the serotypes 11, 15, and 23B became predominant over vaccine-type clusters after vaccination. Finally...

Epidemiology of Human Sporotrichosis Investigated by Amplified Fragment Length Polymorphism

Neyra, Edgar; Fonteyne, Pierre-Alain; Swinne, Danielle; Fauche, Frederic; Bustamante, Beatriz; Nolard, Nicole
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2005 EN
Relevância na Pesquisa
36.23%
Amplified fragment length polymorphism (AFLP) was used to analyze the genetic diversity of Peruvian strains of Sporothrix schenckii and to compare them to a panel of non-Peruvian strains. AFLP analysis suggests that the Peruvian strains can be divided into two homogeneous clusters with no reference to geographical origin or the clinical form of sporotrichosis. The strains from abroad present heterogeneous profiles, with the Bolivian strain and the Colombian strains related to one of the Peruvian population. Sequencing of internal transcribed spacer 2, used to examine the relationships over a longer distance, confirmed the division of Peruvian strains into two populations that can be identified on the basis of a single but specific sequence divergence. This paper introduces automated AFLP analysis as a valuable tool for further investigation of the epidemiology and ecology of S. schenckii.

Molecular Epidemiology of Norovirus Infections in Stockholm, Sweden, during the Years 2000 to 2003: Association of the GGIIb Genetic Cluster with Infection in Children

Lindell, Annika Tiveljung; Grillner, Lena; Svensson, Lennart; Wirgart, Benita Zweygberg
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2005 EN
Relevância na Pesquisa
36.23%
The incidence of norovirus-associated gastroenteritis and the molecular epidemiology of norovirus strains were studied during three seasons (2000-2001, 2001-2002, and 2002-2003) among patients of all ages, mainly from the Stockholm region in Sweden. A total of 3,252 fecal samples were analyzed by reverse transcription-PCR. The incidences of norovirus infection among adults were 23, 26, and 30% during the three seasons studied and 18, 11, and 15% among children 0 to 15 years of age. During the first season, all norovirus strains detected by PCR were typed either by reverse line blot hybridization or nucleotide sequence analysis. During the two successive seasons, a total of 60 norovirus-positive strains from the beginning, peak, and end of the seasons were selected for nucleotide sequence analysis. We identified two dominant norovirus variants over the seasons: a new norovirus variant, recently described as the GGIIb genetic cluster, dominated among children during the first season, and during the following two seasons, a GGII-4 variant dominated. Our data suggest that norovirus infections are common, not only among adults, but also among children, and that some strains may predominantly affect children.

Molecular Epidemiology of Neisseria meningitidis Isolated in the African Meningitis Belt between 1988 and 2003 Shows Dominance of Sequence Type 5 (ST-5) and ST-11 Complexes

Nicolas, Pierre; Norheim, Gunnstein; Garnotel, Eric; Djibo, Saacou; Caugant, Dominique A.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2005 EN
Relevância na Pesquisa
36.23%
At the two World Health Organization Collaborating Centers for Reference and Research on Meningococci in Marseilles, France, and Oslo, Norway, the multilocus sequence typing technique was used for the characterization of a total of 357 strains of meningococci isolated from meningitis cases in 13 African countries of the meningitis belt between 1988 and 2003. Among these strains, 278 of 357 (77.9%) belonged to the sequence type 5 (ST-5) complex; 23.2% were ST-5 and 53.5% were ST-7. ST-5 was probably introduced in Africa in 1987 and was responsible for most of the meningitis cases between 1988 and 2001. ST-7 emerged in the mid-1990s and has totally replaced ST-5 since 2002. These two STs characterized serogroup A strains and have been responsible for hundreds of thousands of cases. Fifty-two strains (14.3%) belonged to the ST-11 complex. The ST-11 complex was characterized by serogroup W135, which has been responsible for an increasing number of sporadic cases since 2000 and the first W135 epidemic ever seen in Africa (in Burkina Faso in 2002). Identification of W135 ST-11 strains in many countries is a great concern for the region. Apart from these two major clonal complexes, a few other clones, such as ST-2881, ST-181, and ST-751, were sporadically detected. Careful surveys for these clones need to be conducted...

Campylobacter coli in Swine Production: Antimicrobial Resistance Mechanisms and Molecular Epidemiology

Thakur, Siddhartha; Gebreyes, Wondwossen A.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /11/2005 EN
Relevância na Pesquisa
36.23%
The aim of this study was to determine antimicrobial resistance, to evaluate and compare the use of two genotyping methods for molecular epidemiology purposes, and to determine the genotypic diversity of Campylobacter coli of porcine origin. A total of 100 C. coli isolates from swine were tested for susceptibility to six antimicrobials using the agar dilution method and genotyped using two high-resolution fingerprinting approaches: multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Evaluation of the methods was based on their resistance patterns, discriminatory indexes (DI), high test throughputs, costs, and turnaround times. Resistance to erythromycin and tetracycline was the most common. Both genotypic methods were found to have high discriminatory power, although MLST had a higher DI (0.936) than PFGE (DI = 0.889). It also had a higher throughput than PFGE. Isolates were clustered into 27 groups by MLST compared to 11 by PFGE. MLST was able to further discriminate the isolates grouped under the same cluster by PFGE. Out of the 65 MLST sequence types (STs) identified among the total isolates, 50 were reported for the first time. Most STs were found to be specific to the farm (n = 38) and to slaughter (n = 22). Resistance against tetracycline and erythromycin was encoded by the tet(O) gene and a A2075G point mutation in the 23S rRNA gene...

Molecular Epidemiology of Haemophilus influenzae Type b Causing Vaccine Failures in the United Kingdom

Aracil, Belén; Slack, Mary; Pérez-Vázquez, María; Román, Federico; Ramsay, Mary; Campos, José
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2006 EN
Relevância na Pesquisa
36.23%
Haemophilus influenzae type b (Hib) was a major cause of pediatric disease in the United Kingdom prior to the introduction of routine Hib immunization in 1992. An unexpected resurgence of cases of vaccine failure was observed with fully vaccinated children from 1999 onward. We investigated whether Hib isolates causing vaccine failures in the United Kingdom could have undergone a change in their population structure to elude the protective effect of Hib vaccine. Molecular epidemiology studies were carried out with 376 isolates from invasive infections (164 vaccine failures and 212 controls). Genetic variability was higher in controls than in vaccine failures. Of the four major clusters obtained, cluster I comprised 92.2% of the total isolates: 156 vaccine failures (95%) and 193 (91%) controls. Cluster IV was specific for vaccine failures but included only four isolates. The increased number of cases of invasive Hib in fully vaccinated children in the United Kingdom was caused by isolates belonging not to a particular or new genotype but to genotypes already circulating in the prevaccination era, before conjugate Hib vaccines were available.

Molecular Epidemiology of Group A Rotavirus Diarrhea among Children in Buenos Aires, Argentina, from 1999 to 2003 and Emergence of the Infrequent Genotype G12

Castello, A. A.; Argüelles, M. H.; Rota, R. P.; Olthoff, A.; Jiang, B.; Glass, R. I.; Gentsch, J. R.; Glikmann, G.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /06/2006 EN
Relevância na Pesquisa
36.23%
To examine the epidemiology of rotaviruses in Buenos Aires, Argentina, we screened 1,212 stool samples from children with diarrhea in the southern district of Buenos Aires from 1999 to 2003. We identified 187 samples (15.4%) that were positive for group A rotavirus by use of antigen enzyme-linked immunosorbent assay. Among these specimens, 112 were available for typing: 93 (83.0%) were single-type infections, 9 (8.0%) were mixed-type infections with more than one G or P type, and 10 (8.9%) were G and/or P nontypeable. In contrast to the findings in our last study, from 1996 to 1998, genotype P[4], G2 strains were almost completely absent and P[8], G1 and P[8], G4 strains were dominant, representing more than 80% of the G and P types found. Genotypes G2 and G9 were detected in few samples, and type G3 was completely absent. We identified several uncommon genotype G12 strains, representing the first detections outside of Asia and the United States, by sequencing. Using a genotype G12-specific reverse transcription-PCR, we identified eight (6.7%) positive samples for the 1999 to 2003 period. The high degree of sequence identity between recent G12 isolates from Argentina, the United States, and Asian countries suggests a relatively recent introduction(s) of these strains into humans from a common progenitor. The Argentinean G12 strains belonged to genotype P[9]...

Molecular Epidemiology of Neisseria gonorrhoeae in Amsterdam, The Netherlands, Shows Distinct Heterosexual and Homosexual Networks

Kolader, Marion-Eliëtte; Dukers, Nicole H. T. M.; van der Bij, Akke K.; Dierdorp, Mirjam; Fennema, Johan S. A.; Coutinho, Roel A.; Bruisten, Sylvia M.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2006 EN
Relevância na Pesquisa
36.23%
Molecular typing, added to epidemiological data, can better identify transmission patterns of gonorrhea in Western countries, where the incidence has recently been rising. From September 2002 to September 2003, patients with a laboratory-confirmed diagnosis of gonorrhea at the Clinic for Sexually Transmitted Infections in Amsterdam, The Netherlands, were subjected to a questionnaire pertaining to sexual risk behavior and sexual partners in the 6 months prior to the diagnosis. The Neisseria gonorrhoeae isolates were all genotyped using PCR-restriction fragment length polymorphism of the porin and opacity genes. All patients with a completed questionnaire and genotyped isolates were included in the study. We obtained 885 N. gonorrhoeae isolates from 696 patients that revealed 88 clusters and 46 unique genotypes. Patients infected at multiple anatomical sites with one or more strains and patients infected several times during the study period were shown to pursue high-risk sexual behavior and were considered core groups. There were 11 clusters of ≥20 patients; in seven clusters, 81% to 100% of patients were men who have sex with men (MSM), three clusters contained 87 to 100% heterosexual men and women, and one cluster was formed by equal proportions of MSM and heterosexual male and female patients. However...

Multilocus Sequence Typing of Historical Burkholderia pseudomallei Isolates Collected in Southeast Asia from 1964 to 1967 Provides Insight into the Epidemiology of Melioidosis

McCombie, Roberta L.; Finkelstein, Richard A.; Woods, Donald E.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2006 EN
Relevância na Pesquisa
36.23%
A collection of 207 historically relevant Burkholderia pseudomallei isolates was analyzed by multilocus sequence typing (MLST). The strain collection contains environmental isolates obtained from a geographical distribution survey of B. pseudomallei isolates in Thailand (1964 to 1967), as well as stock cultures and colony variants from the U.S. Army Medical Research Unit (Malaysia), the Walter Reed Army Institute for Research, and the Pasteur Institute (Vietnam). The 207 isolates of the collection were resolved into 80 sequence types (STs); 56 of these were novel. eBURST diagrams predict that the historical-collection STs segregate into three complexes when analyzed separately. When added to the 760 isolates and 365 STs of the B. pseudomallei MLST database, the historical-collection STs cluster significantly within the main complex of the eBURST diagram in an ancestral pattern and alter the B. pseudomallei “population snapshot.” Differences in colony morphology among reference isolates were found not to affect the STs assigned, which were consistent with the original isolates. Australian ST84 is likely characteristic of B. pseudomallei isolates of Southeast Asia rather than Australia, since multiple environmental isolates from Thailand and Malaysia share this ST with the single Australian clinical isolate in the MLST database. Phylogenetic evidence is also provided suggesting that Australian isolates may not be distinct from those of Thailand...

Comparative Analysis of Prevalence, Risk Factors, and Molecular Epidemiology of Antibiotic-Associated Diarrhea Due to Clostridium difficile, Clostridium perfringens, and Staphylococcus aureus

Asha, N. J.; Tompkins, D.; Wilcox, M. H.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2006 EN
Relevância na Pesquisa
36.23%
We prospectively studied the comparative epidemiology and risk factors for Clostridium difficile, Clostridium perfringens, and Staphylococcus aureus antibiotic-associated diarrhea (AAD). Four thousand six hundred fifty-nine inpatient fecal specimens (11 months) were tested for C. difficile cytotoxin, C. perfringens enterotoxin, and S. aureus by Vero cell assay, enzyme-linked immunosorbent assay, and growth on fresh blood agar, respectively. Two distinct age-, sex-, and location-matched control patient groups were used for multivariate logistic regression risk factor analyses: symptomatic patients who were AAD pathogen negative and asymptomatic patients with histories of recent antimicrobial therapy. All AAD pathogen isolates were DNA fingerprinted. In AAD cases, the prevalences of C. difficile cytotoxin, C. perfringens enterotoxin, and S. aureus were 12.7%, 3.3%, and 0.2%, respectively (15.8% overall). Age of >70 years was a common risk factor. Other risk factors for infective AAD and C. difficile AAD included length of hospital stay and use of feeding tubes (length of stay odds ratios [OR], 1.017 and 1.012; feeding tube OR, 1.864 and 2.808). Female gender and use of antacids were significantly associated with increased risk of C. perfringens AAD (OR...

Use of a Single-Nucleotide Polymorphism Genotyping System To Demonstrate the Unique Epidemiology of Methicillin-Resistant Staphylococcus aureus in Remote Aboriginal Communities

McDonald, Malcolm; Dougall, Annette; Holt, Deborah; Huygens, Flavia; Oppedisano, Frances; Giffard, Philip M.; Inman-Bamber, John; Stephens, Alex J.; Towers, Rebecca; Carapetis, Jonathan R.; Currie, Bart J.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2006 EN
Relevância na Pesquisa
36.23%
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a major public health problem in Australia, as in many other parts of the world. High rates of CA-MRSA skin and soft tissue infection have been reported from Aboriginal communities. We used a single-nucleotide polymorphism (SNP) genotyping typing system based on the multilocus sequence type (MLST) database to investigate the epidemiology of CA-MRSA and methicillin-sensitive S. aureus (MSSA) over a 12-month period in three remote Aboriginal communities of Northern Australia. This was supplemented by real-time PCR for Panton-Valentine leukocidin (PVL) genes, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial susceptibility testing. S. aureus was recovered from pyoderma lesions on 221 occasions and throat swabs on 44 occasions. The median monthly recovery rate of S. aureus from skin sores was 58% (interquartile range, 62 to 78%), and there was no seasonal variation. Twenty-three percent of isolates were CA-MRSA; the proportion was similar across the communities and did not vary over the study period. Erythromycin resistance was found in 47% of CA-MRSA and 21% of MSSA. SNP-based typing identified 14 different clonal complexes (cc); however...

Molecular Epidemiology of G9 Rotaviruses in Taiwan between 2000 and 2002

Lin, Yi-Pei; Chang, Sui-Yuan; Kao, Chuan-Liang; Huang, Li-Min; Chung, Ming-Yi; Yang, Jyh-Yuan; Chen, Hour-Young; Taniguchi, Koki; Tsai, Keh-Sung; Lee, Chun-Nan
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2006 EN
Relevância na Pesquisa
36.23%
Since the mid-1990s, novel G9 rotaviruses have been detected in many countries, suggesting that G9 is a globally important serotype. The molecular epidemiology of G9 rotaviruses in Taiwan from 2000 to 2002 was investigated in this study. G9 rotavirus first appeared in 2000 with 4 cases and constituted 33.8% and 54.8% of the rotavirus-positive samples in 2001 and 2002, respectively. These G9 strains belonged to P[8]G9, subgroup II, and long electropherotype, except one belonged to P[4]G9, subgroup II, and short electropherotype. Nucleotide sequencing and phylogenetic analysis of 52 Taiwanese G9 rotaviruses showed that the VP7 genes shared a high degree of identity to overseas G9 rotaviruses detected after 1993 and that the VP8* portions of the VP4 genes were more closely related to those of local rotaviruses of other G types. The two P[8]G9 strains with high nucleotide identities in the VP7 and the partial VP4 genes, 01TW591 of Taiwan from 2001 and 95H115 of Japan from 1995, varied in four genes, genes 2, 3, 7, and 8, which was revealed by RNA-RNA hybridization. Representative strains for different RNA patterns were also analyzed in the partial VP2 and VP3 genes; the nucleotide identities were high between Taiwanese G9 strains and local G3 or G2 strains. These results suggested that Taiwanese G9 rotaviruses possibly had evolved through reassortment between overseas G9 strains and circulating rotaviruses of other G types.

Molecular Epidemiology of Hospital-Acquired Vancomycin-Resistant Enterococci▿

Abele-Horn, Marianne; Vogel, Ulrich; Klare, Ingo; Konstabel, Carola; Trabold, Rene; Kurihara, Risa; Witte, Wolfgang; Kreth, Wolfgang; Schlegel, Paul-Gerhardt; Claus, Heike
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
EN
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Vancomycin-resistant Enterococcus faecium strains are a significant cause of nosocomial infections in predisposed patients. Multiple-locus variable-number tandem repeat analysis (MLVA) has been validated recently by use of a global strain collection. In this report, we applied MLVA together with multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) to type 14 isolates from three clusters of patients colonized or infected with vancomycin-resistant Enterococcus faecium and another 10 epidemiologically unrelated isolates from the same hospital. The clusters could be distinguished by all three typing methods, which proved to be concordant. PFGE patterns provided the highest resolution. We observed seven sequence types (ST), six MLVA types (MT), and nine distinct ST/MT combinations. The combination of MLST and MLVA may be an alternative to PFGE in hospital epidemiology, providing the benefits of high accuracy, reproducibility, and portability.