Seroprevalence of West Nile Virus in Tampa Bay Florida Patients Admitted to Hospital during 2020-2021 for Respiratory Symptoms.

West Nile virus (WNV) is an arbovirus spread primarily by Culex mosquitoes, with humans being a dead-end host. WNV was introduced to Florida in 2001, with 467 confirmed cases since. It is estimated that 80 percent of cases are asymptomatic, with mild cases presenting as a non-specific flu-like illness. Currently, detection of WNV in humans occurs primarily in healthcare settings via RT-PCR or CSF IgM when patients present with severe manifestations of disease including fever, meningitis, encephalitis, or acute flaccid paralysis. Given the short window of detectable viremia and requirement for CSF sampling, most WNV infections never receive an official diagnosis. This study utilized enzyme-linked immunosorbent assay (ELISA) to detect WNV IgG antibodies in 250 patient serum and plasma samples collected at Tampa General Hospital during 2020 and 2021. Plaque reduction neutralization tests were used to confirm ELISA results. Out of the 250 patients included in this study, 18.8% of them were IgG positive, consistent with previous WNV exposure. There was no relationship between WNV exposure and age or sex.

Autochthonous Plasmodium vivax Infections, Florida, USA, 2023.

During May-July 2023, a cluster of 7 patients at local hospitals in Florida, USA, received a diagnosis of Plasmodium vivax malaria. Whole-genome sequencing of the organism from 4 patients and phylogenetic analysis with worldwide representative P. vivax genomes indicated probable single parasite introduction from Central/South America.

Validation of a new extraction-free real-time PCR test to detect MPOX virus.

The monkeypox (Mpox) virus has raised significant concerns given its recent spread with an increasing number of confirmed cases worldwide. In this study, we evaluated the performance of a laboratory developed test (LDT) using BioGX Xfree hMPXV/OPXV reagents for the qualitative detection of non-variola Orthopoxviruses and Mpox virus DNA, in swabs from human pustular or vesicular rash specimens. Analytical and clinical testing analysis were carried out on two different platforms: the BD MAX™ System (BD Diagnostics) and the new pixl.16 Real-Time PCR Platform (BioGX), using a synthetic Mpox virus DNA (ATCC VR-3270SD) and residual clinical samples previously identified with an EUA approved Mpox real-time PCR assay. In the end, the Xfree hMPXV/OPXV LDT proved to be a sensitive, specific, and reproducible test for the detection of Mpox on both platforms evaluated with the pixl.16 having an advantage of a small footprint and providing faster TAT facilitated by an extraction-free workflow.

Clinical Evaluation of the Alinity m STI Multiplex PCR Assay.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are routinely tested and reported; however, Trichomonas vaginalis (TV) is the most common sexually transmitted infection (STI) in the United States and the prevalence of Mycoplasma genitalium (MG) infections is likely higher than estimated. We examined the clinical performance of the Alinity m STI assay for detection and surveillance of CT/NG/TV/MG in urine specimens from patients at a large academic medical center. METHODS: Urine specimen from 198 patients was tested in this evaluation. Alinity m STI and Aptima Combo 2 CT/NG and TV assay (Panther System) results were compared, with discrepant results run on the cobas 6800 CT/NG, TV/MG assays. Analyzer turnaround times, time from loading the specimen on the analyzer to results reporting, were determined for Alinity m and Panther systems. RESULTS: Overall percent agreements of the Alinity m in comparison with the Aptima and cobas assays for CT, NG, TV, and MG were 99.5% (97.2%, 99.9%), 99.5% (97.2%, 99.9%), 98.4% (95.5%, 99.5%), and 86.4% (66.7%, 95.3), respectively. There were 5 discrepant samples (CT, 1; NG, 1; TV, 3) between the Alinity m and the Aptima assays, and 3 MG discrepant samples between the Alinity m STI and cobas 6800. Two of the 5 Aptima and Alinity m discrepant samples were resolved as they yielded similar results on both Alinity m and cobas 6800. TV and MG infections comprised 54% of the positive samples and were more often asymptomatic than CT and NG infections. Analyzer turnaround time was 3 hours 25 minutes for the Aptima CT/NG, 3 hours 25 minutes for Aptima TV, and 1 hour 55 minutes for Alinity m STI assay. CONCLUSIONS: The Alinity m STI assay allows for fast and simultaneous detection of the 4 major STI pathogens, which can facilitate surveillance and provide accurate results to help clinicians diagnose for initiation of appropriate treatment.

Multicenter evaluation of BioCode GPP for syndromic molecular detection of gastrointestinal pathogens from stool specimens.

Acute gastroenteritis (AGE) is a leading cause of morbidity and mortality worldwide across all age groups that disproportionally affects young children in low- and middle-income countries and immunocompromised patients in high-income countries. Regional outbreaks of AGE are typically detected by traditional microbiological detection methods that target limited organisms and are associated with low sensitivity and lengthy time-to-results. Combined, these may result in repeat testing, imprecise or delayed treatment, and delayed recognition of outbreaks. We conducted a multi-site prospective study comparing the BioCode Gastrointestinal Pathogen Panel (BioCode GPP) for the detection of 17 common bacterial, viral, and protozoan causes of gastroenteritis with reference methods, including stool culture, enzyme immunoassays, pathogen-specific PCR assays, and sequencing. One thousand five hundred fifty-eight residual, de-identified stool samples (unpreserved stool and stool in Cary-Blair transport medium) were enrolled and tested for 11 bacterial, 3 viral, and 3 protozoan pathogens. BioCode GPP and reference methods were positive for 392 (25.2%) and 283 (18.2%) samples, respectively (P < 0.0001). In this study, the BioCode GPP and reference methods detected 69 and 65 specimens positive for Clostridioides difficile, 51 and 48 for enteroaggregative Escherichia coli, 33 and 27 for enterotoxigenic E. coli, 50 and 47 for norovirus GI/GII, and 30 and 22 for rotavirus A, respectively. The BioCode GPP showed good positive and negative agreements for each pathogen ranging from 89.5% to 100%, with overall sensitivity and specificity of 96.1% and 99.7%, post adjudication. The BioCode GPP detected >1 pathogens in 49 samples, representing 12.5% of the total 392 positive specimens. IMPORTANCE: This study highlights performance of a novel technology for timely and accurate detection and differentiation of 17 common bacterial, viral, and protozoan causes of gastroenteritis. Utilizing molecular tests such as the BioCode Gastrointestinal Pathogen Panel may improve the detection of gastrointestinal pathogens and provide actionable results, particularly for patient populations at most risk.

Molecular characterization of vancomycin-resistant Enterococci strains eight years apart from its first isolation in São Paulo, Brazil / Caracterização molecular de espécies de Enterococci resistentes à vancomicina oito anos após seu primeiro isolamento em São Paulo, Brasil

E. faecium was the first reported VRE species, carrying the vanA gene in Brazil. In spite of this, vancomycin-resistant E. faecalis has become the predominant species in Brazilian hospitals. The aim of this study was to evaluate the genetic relatedness of VREs isolated in a Brazilian teaching hospital eight years apart from its first isolation. We analyzed 38 VRE strains obtained from 81 surveillance cultures of patients admitted to the four largest intensive care units in Hospital São Paulo in February, 2006. Presence of the vanA gene was assayed by PCR and PFGE analysis was used for molecular characterization. All VRE strains carried the vanA gene. Two distinct clonal groups were observed among vancomycin-resistant E. faecalis. Vancomycin-resistant E. faecium belonged to five distinct clones were demonstrated by molecular typing. All of these clones were different from the first vancomycin-resistant enterococci clone isolated eight years ago in our hospital.

E. faecium contendo o gene vanA foi a primeira espécie de VRE descrita, no Brasil. Apesar disto, E. faecalis resistente a vancomicina tem se tornado a espécie predominante nos hospitais brasileiros.O objetivo desse estudo foi avaliar a relação genética de VREs isolados em um hospital de ensino brasileiro após oito anos de seu primeiro isolamento. Analisamos 37 isolados de VRE obtidos de 81 culturas de vigilância de pacientes admitidos nas quatro maiores Unidades de Tratamento Intensivo em Fevereiro de 2006. A presença do gene vanA foi analisada por PCR e a caracterização molecular por PFGE. Todas as amostras VRE carreavam o gene vanA. Entre os E. faecalis vancomicina-resistentes, dois distintos grupos clonais foram observados. E. faecium resistente a vancomicina pertencentes a cinco clones distintos foram demonstrados por tipagem molecular. Todos esses clones foram diferentes do primeiro clone de enterococo resistente a vancomicina isolado oito anos atrás em nosso hospital.

Genetic relatedness among clinical strains of Stenotrophomonas maltophilia in tertiary care hospital settings in São Paulo State, Brazil

Stenotrophomonas maltophilia is a Gram-negative bacillus, which is becoming widely recognized as an important nosocomial pathogen. The main objective of this study was to evaluate the genetic relatedness, by random amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) of 86 clinical isolates of S. maltophilia (colonization 22, infection 64) obtained from 79 hospitalized patients, from different geographic regions of São Paulo State. The genotypic analysis performed by RAPD and PFGE was used in 24 isolates for genetic identity confirmation. The results were congruent between the two methods but it was not possible to link genetic profiles with the studied variables, clinical state and geographic area, probably due to the great variability among the strains. The analyses by PFGE confirmed identity in 5 pairs of microorganisms and RAPD, in this study, showed to be a useful tool for investigation of diversity leading the identification of 85 genetic profiles. The genetic diversity shown may be due to re-infection by different strains or co-infection by multiple strains which suggests multiple entry sources of the bacterium in the hospital setting or of acquisition by patient. In this setting, colonization, infection and re-infection occur with unknown frequency, raising the need for the establishment of specific control measures.

Stenotrophomonas maltophilia é um bacilo Gram-negativo, conhecido como importante patógeno nosocomial. O principal objetivo desse estudo foi avaliar a relação genética, através da análise randômica do polimorfismo de DNA (RAPD) e eletroforese em gel de campo pulsado (PFGE), de 86 isolados clínicos de S. maltophilia (22 de colonização, 64 de infecção) obtidos de 79 pacientes hospitalizados em diferentes regiões geográficas do estado de São Paulo. A análise genotípica foi realizada através da técnica RAPD e o PFGE foi usado em 24 isolados para confirmar a identidade genética dos mesmos. Os resultados foram coerentes entre os dois métodos, mas não foi possível correlacionar um perfil genético com as variáveis estudadas, estado clínico e área geográfica, provavelmente pela ampla variabilidade entre as linhagens. A análise por PFGE confirmou a identidade genética em 5 pares de microrganismos e o RAPD, neste estudo, mostrou ser uma ferramenta útil para investigação da diversidade, possibilitando identificar 85 perfis genéticos. A diversidade genética observada através do RAPD pode ser devido à re-infecção por diferentes linhagens ou co-infecção por linhagens distintas, sugerindo múltiplas fontes de entrada da bactéria no hospital ou de aquisição pelo paciente. Nesse ambiente, a colonização, infecção e re-infecção ocorrem com freqüência, o que leva à necessidade do estabelecimento de medidas de controle específicas.

Tipagem molecular de bacilos grem-negativos não-fermentadores / Molecular typing of non-fermentative gram-negative bacilli: comparison and application of different techniques

OBJETIVOS: (a) Avaliar três técnicas para a tipagem molecular de bacilos Gram-negativos não-fermentadores (BGN-NF) isolados na América Latina (AL); (b) propor modificações na técnica PFGE para bactérias sensíveis a degradação do DNA; e (c) avaliar a aplicabilidade destas técnicas de tipagem molecular em estudos longos de epidemiologia hospitalar. MÉTODOS: Três coleções diferentes de bactérias foram avaliadas. Primeiro foi estudado um grupo de 126 BGN-NF (64 P. aeruginosa, 42 A. baumannii e 20 S. maltophifa) isolados do sangue de pacientes atendidos em 10 centros médicos localizados na AL no ano de 1998 e. de pacientes atendidos no Hospital São Paulo (HSP) entre os anos de 1999 e 2001. Todos estes isolados clínicos foram submetidos à tipagem molecular pelas técnicas ribotipagem automatizada, PFGE e ERIC-PCR. O poder discriminatório (PD) de cada técnica foi calculado utilizando a fórmula de Hunter. Um segundo grupo de amostras bacterianas foi composto por 66 isolados clínicos sensíveis a degradação do DNA pela técnica PFGE e incluiu as seguintes espécies: E. coli (22 amostras), K. pneumoniae (4 amostras), E. cloacae (2 amostras), S. marcescens (12 amostras), P. aeruginosa (17 amostras), Acinetobacter spp. (5 amostras) e Salmonella spp. (4 amostras). Todas as 66 amostras foram submetidas à tipagem molecular pela técnica PFGE, sendo que a eletroforese foi realizada com e sem a adição de tiourea no tampão de corrida TBE. Um terceiro grupo incluiu 26 isolados clínicos de P. aeruginosa resistentes ao imipenem (PARI), isolados de pacientes atendidos no HSP durante um período de 6 anos (1997 a 2002). Todas as amostras eram representantes de feridas cirúrgicas e foram submetidas à tipagem molecular utilizando as técnicas PFGE e ribotipagem automatizada. RESULTADOS: Todas as amostras pertencentes ao primeiro grupo foram tipáveis pelas técnicas ERIC-PCR e ribotipagem automatizada e duas (1,6 por cento) amostras não foram tipáveis pela técnica PFGE. As três técnicas apresentaram 100 por cento de reprodutibilidade. O tempo necessário para realização da ribotipagem automatizada e ERIC-PCR foram menores quando comparados com o tempo necessário para realização do PFGE. O ERIC-PCR e o PFGE apresentaram custo mais baixo que a ribotipagem automatizada; no entanto, a interpretação dós resultados pelo ERIC-PCR foi mais difícil. As três técnicas…

The use of molecular typing to evaluate the dissemination of antimicrobial resistance among gram-negative rods in Brazilian hospitals

Antimicrobial resistance has increased rapidly in Brazil and worldwide during the past few years, giving rise to a growing necessity for antimicrobial resistance surveillance programs. These programs have been instituted in order to monitor bacterial resistance in various regions, and to guide empirical antimicrobial therapy. We evaluated the use of molecular typing in multicenter surveillance programs. We also studied the dissemination modes of selected resistance profiles. Antimicrobial susceptibility to various antimicrobial agents was evaluated by the reference broth microdilution method. Bacterial isolates with selected susceptibility patterns were characterized by pulsed field-gel electrophoresis (PFGE). A total of 119 Gram-negative bacteria were molecularly typed, including 22 imipenem-resistant Pseudomonas aeruginosa, 26 ESBL-producing Escherichia coli, 27 cefoxitin-resistant-ESBL-producing Klebsiella pneumoniae, 33 Enterobacter spp., 8 Citrobacter spp., and 3 S. marcescens isolates resistant to ceftazidime. The isolates were from clinically apparent bacteremia of patients hospitalized in medical centers located in 13 cities of 11 Brazilian states. Our molecular typing results revealed a great genetic diversity among isolates of the same species. However, some major PFGE patterns were found in more than one isolate. All repeated PFGE patterns were detected in only 2 isolates, which were isolated within the same institutions or in different medical centers. We conclude that the ability to characterize organisms phenotypically and genotypically is a powerful epidemiologic tool and it provides unique information that is very important for multicenter surveillance programs.

Avaliaçäo da qualidade dos discos com antimicrobianos para testes de disco-difusäo disponíveis comercialmente no Brasil / Evaluation of the quality of the antimicrobial agents disks used in disk-diffusion tests comercially available in Brazil

Introduçäo: O teste de suscetibilidade a antimicrobianos representa um dos testes de maior importância clínica realizados pelo laboratório de microbiologia. Devido ao grande número de antimicrobianos e à complexidade dos mecanismos de resistência desenvolvidos pelas bactérias, fica muito difícil hoje a detecçäo de problemas nos testes de suscetibilidade pela simples avaliaçäo dos resultados obtidos. Sendo assim, é extremamente importante que haja uma avaliaçäo constante da qualidade destes testes. Objetivo: O objetivo do presente estudo foi avaliar a qualidade dos discos de antimicrobianos comercializados no Brasil. Material e métodos: Foram avaliados discos de 18 antimicrobianos obtidos de cinco diferentes fontes comerciais, os quais foram testados frente a quatro cepas bacterianas oriundas da ATCC, pelo método de difusäo em ágar, seguindo as recomendações do National Committee for Clinical Laboratory Standards (NCCLS). Cada teste foi repetido 20 vezes. Resultados: Nenhuma das marcas apresentou desempenho satisfatório para o uso na rotina de um laboratório de microbiologia. O melhor desempenho foi apresentado pela marca Cecon, com 89,6 por cento de concordância. A marca Sensifar apresentou taxa de concordância geral semelhante (90,8%). A marca com o pior desempenho foi a Pimenta Abreu, com apenas 58,6% de concordância. Conclusäo: Os resultados do presente estudo indicam que os discos de antimicrobianos comercializados no Brasil são de baixa qualidade, possivelmente refletindo a falta de controle de qualidade na produçäo e/ou estocagem dos produtos antes da sua distribuiçäo. Esses dados chamam a atençäo para a necessidade de implantaçäo de sistemas efetivos de fiscalizaçäo da comercializaçäo desses produtos e de programas criteriosos de controle de qualidade por parte dos laboratórios que os utilizam

In vitro antimicrobial activity of piperacillin/tazobactam in comparison with other broad-spectrum ß-Lactams

Combinig tazobactam, a ß-lactamase inhibitor, with the ureidopenicillin, piperacillin, successfully restores the activity of piperacillin against ß-lactamase producing bacteria. Thus, piperacillin/tazobactam is highly active against most clinically important species of Gram-negative and Gram-positive bacteria, including anaerobes. We evaluated the in vitro activity of piperacillin/tazobactam against clinical isolates from a tertiary university hospital located in Säo Paulo, Brazil. Its activity was compared to the ticarcillin/ clavulanic acid, ampicillin/sulbactam, ceftazidimeceftriaxone, cefotaxime, cefoxitin, aztreonam and imipenem against 820 isolates (608 Gram-negative and 212 Gram-positive) collected from hospitalized patients in 1999. The most frequent species tested were Pseudomonas aeruginosa (168/20 por cento), Escherichia coli (139/17 por cento), Acinetobacter spp (131/16 porcento), and Staphylococcus aureus (76/9 por cento). Of the isolates studied, 30 por cento were from the blodstream, 16 porcento from the lower respiratory tract, and 11 por cento from surgical wounds or soft tissue. The isolates were susceptibility tested by the broth microdilution method according to NCCLS procedures. The isolates tested were highly resistant to most antimicrobial agents evaluated. Imipenem resistance was not verified among Enterobacteriaceae, and piperacillin/tazobactam was the second most active ß-lactam against this group of bacteria (80.0 por cento susceptibility). Extended-spectrum ß-lactamase production was very high among E. coli (approximately 20 por cento) and KLebsiella pneumoniae (approximately 40 por cento). Imipenem was uniformly active against these species (100 por cento susceptibility) and piperacillin/tazobactam was the second most active compound inhibiting 84.4 por cento of isolates. Pseudomonas aeruginosa was highly resistant to all ß-lactams evaluated and piperacillin/tazobactam was the most active compound against this species. Our results demonstrate an extremely high level of antimicrobial resistance in the hospital evaluated, especially among non-enteric Gram-negative bacilli. Due to this high level of resistence, piperacillin/tazobactam represents an important ciontribution to the treatment of nosocomial infections...

Staphylococcus sp. coagulase-negativa em hemoculturas de pacientes com menos de sessenta dias de idade: infecçäo versus contaminaçäo / Coagulase-negative Staphylococcus sp. in blood cultures from infants less than 60 days old: infection versus contamination

Objetivo: O presente estudo teve como objetivo determinar a prevalência de infecçäo versus contaminaçäo em pacientes com menos de 60 dias de vida, que possuíram hemoculturas positivas para Staphylococus sp. coagulase negativa. material e Métodos: Foram estudadas 45 hemoculturas positivas para essa bactéria de 41 pacientes, no período de 1§. de fevereiro a 31 de julho de 1993. Conforme informaçöes clínicas e laboratoriais obtidas através da revisäo dos prontuários, os pacientes foram separados em 3 grupos: I - pacientes infectados, II - pacientes näo infectados e III - casos duvidosos. Resultados: Os resultados mostraram que 11 pacientes (26,8 por cento) pertenciam ao grupo I 25 (61 por cento) pertenciam ao grupo II (hemoculturas contaminadas) e 5 (12,2 por cento), ao grupo III...

Hemoculturas no Hospital de Clinicas de Porto Alegre: uma analise de seis meses / Blood cultures at Hospital de Clinicas de Porto Alegre: a six months review

A presenca de microorganismos na corrente sanguinea e um grande problema para medicos e pacientes e a sua ocorrencia normalmente indica algum foco infeccioso. O presente trabalho teve como objetivo determinar o percentual de hemoculturas positivas em pacientes internados no Hospital de Clinicas de Porto Alegre (HCPA) e o tempo levado para a liberacao destes resultados, alem de detectar as bacterias mais comumente encontradas e identificar as unidades com maior numero de hemoculturas positivas. Foram colhidas 4798 amostras de hemoculturas de 1399 pacientes internados no HCPA entre fevereiro e julho de 1993, as amostras foram processadas na Unidade de Microbiologia deste hospital. Nahnalise dos resultados, observamos que 11,6 por cento das amostras foram positivas e o tempo medio para a liberacao do resultado final foi de 4,48 +ou- 2,06 dias para estas amostras. Staphylococcus aureus foi a bacteria mais comumente isolada e a unidade de Internacao Clinica teve o maior percentual de positividade