Identification of Salmonella enterica serovar Typhi strain from a young Brazilian patient: the relevance of automated microbiological methods for the rapid diagnosis of systemic infections

Introduction: Latin American countries have public health problems that are aggravated by inadequate basic sanitary conditions. Inefficient vaccination coverage, as well as the fact that a significant portion of the population is exposed to contaminated water and food, can lead to an increase in the incidence of some diseases. Methodology: the work reports a case of infection by Salmonella enterica serovar Typhi (S. Typhi), whose contagion is strictly related to personal and environmental hygiene conditions. Conclusion: accurate identification and immediate detection of the etiologic agent using automated methods, such as Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and the BACT / ALERT System® 3D, can positively contribute to the patient's prognosis and therapeutic success. Thus, principally in the Latin American, a quick and adequate treatment is of great importance, both for the patient and to minimize the spread of multidrug-resistant strains and the consequent reduction of therapeutic options

Monitoring fluoroquinolone resistance among ESBL-positive and ESBL-negative Escherichia coli strains isolated from urinary tract infections: An alert for empirical treatment

ABSTRACT Background: Bacterial resistance to extended-spectrum beta-lactamases (ESBL) is present worldwide. Empirical antibiotic therapy is often needed, and the use of fluoroquinolones, such as ciprofloxacin and norfloxacin, is common. This study aimed to analyze the urine cultures from 2,680 outpatients in January 2019, 2020, 2021, and 2022, with bacterial counts above 100,000 CFU/mL in which Escherichia coli was the etiological agent. Methods: We monitored the resistance of ESBL-positive and ESBL-negative strains to ciprofloxacin and norfloxacin and evaluated resistance rates. Results: Significantly higher fluoroquinolone resistance rates were observed among ESBL-positive strains in all years studied. Furthermore, a significant increase in the rate of fluoroquinolone resistance was observed between 2021 and 2022 in ESBL-positive and -negative strains, as well as from 2020 to 2021 among the ESBL-positive strains. Conclusions: The data obtained in the present study showed a tendency towards an increase in fluoroquinolone resistance among ESBL-positive and -negative E. coli strains isolated from urine cultures in Brazil. Since empirical antibiotic therapy with fluoroquinolones is commonly used to treat diverse types of infections, such as community-acquired urinary tract infections, this work highlights the need for continuous monitoring of fluoroquinolone resistance among E. coli strains circulating in the community, which can mitigate the frequency of therapeutic failures and development of widespread multidrug-resistant strains

RESISTÊNCIA ANTIMICROBIANA EM STAPHYLOCOCCUS CAPITIS ISOLADO DE HEMOCULTURA: CARACTERIZAÇÃO FENOTÍPICA E ANÁLISES GENÔMICAS

Introdução/Objetivo: Os estafilococos coagulase-negativa (SCoN), membros da microbiota residente da pele humana, apresentam potencial de causar infecções oportunistas, sobretudo quando ocorre o rompimento da barreira cutânea, seja por trauma ou pela introdução de dispositivos médicos. Dentre os SCoN, Staphylococcus capitis destaca-se como uma das espécies mais frequentes em infecções relacionadas à assistência à saúde (IRAS), principalmente no ambiente hospitalar. A letalidade das infecções está diretamente associada à expressão de fatores de virulência e resistência aos agentes antimicrobianos pelo microrganismo. Este trabalho teve por objetivo investigar a resistência antimicrobiana em uma cepa de Staphylococcus capitis subsp. urealyticus isolada de hemocultura através da determinação do perfil de susceptibilidade aos antimicrobianos e da busca por genes de resistência no genoma completamente sequenciado. Métodos: Foi utilizada uma cepa de Staphylococcus capitis oriunda de hemocultura de um indivíduo adulto e previamente identificada por espectrometria de massas MALDI-TOF. O perfil de susceptibilidade aos antimicrobianos foi determinado de acordo com o BrCAST (2023). O genoma da cepa foi extraído, purificado e completamente sequenciado na plataforma NextSeq 550 (Illumina®). A confirmação da espécie foi realizada pela análise de sequência multilocus (MLSA) e a busca por genes de resistência antimicrobiana foi realizada com a ferramenta de bioinformática ResFinder 4.1. Resultados: A cepa de S. capitis subsp. urealyticus exibiu um fenótipo multidroga-resistente (MDR), apresentando resistência à oxacilina, cefoxitina, norfloxacino, entre outros. A cepa foi identificada como S. capitis subsp. urealyticus pela MLSA. Genes que conferem resistência a diversas classes de antimicrobianos, dentre os quais macrolídeos, aminoglicosídeos, β-lactâmicos e lincosamidas, foram encontrados no genoma sequenciado. Conclusão: As análises revelaram a presença de diversos genes de resistência antimicrobiana no genoma da cepa de S. capitis subsp. urealyticus isolada de hemocultura, corroborando o fenótipo MDR exibido. Estes resultados enfatizam a importância de investigar o perfil de susceptibilidade aos antimicrobianos de isolados clínicos de SCoN, bem como alertam para a necessidade de alternativas para o tratamento das IRAS por microrganismos destas espécies expressando perfis de MDR

Multiplex polymerase chain reaction to identify and determine the toxigenicity of Corynebacterium spp with zoonotic potential and an overview of human and animal infections

Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species

Molecular Identification of Nocardia Isolates from Clinical Samples and an Overview of Human Nocardiosis in Brazil

BackgroundNocardia sp. causes a variety of clinical presentations. The incidence of nocardiosis varies geographically according to several factors, such as the prevalence of HIV infections, transplants, neoplastic and rheumatic diseases, as well as climate, socio-economic conditions and laboratory procedures for Nocardia detection and identification. In Brazil the paucity of clinical reports of Nocardia infections suggests that this genus may be underestimated as a cause of human diseases and/or either neglected or misidentified in laboratory specimens. Accurate identification of Nocardia species has become increasingly important for clinical and epidemiological investigations. In this study, seven clinical Nocardia isolates were identified by multilocus sequence analysis (MLSA) and their antimicrobial susceptibility was also determined. Most Nocardia isolates were associated to pulmonary disease.Methodology/Principal Findings The majority of Brazilian human isolates in cases reported in literature were identified as Nocardia sp. Molecular characterization was used for species identification of Nocardia nova, Nocardia cyriacigeorgica, Nocardia asiatica and Nocardia exalbida/gamkensis. Data indicated that molecular analysis provided a different Nocardia speciation than the initial biochemical identification for most Brazilian isolates. All Nocardia isolates showed susceptibility to trimethoprim-sulfamethoxazole, the antimicrobial of choice in the treatment nocardiosis. N. nova isolated from different clinical specimens from one patient showed identical antimicrobial susceptibility patterns and two distinct clones.Conclusions/Significance Although Brazil is the world's fifth-largest country in terms of land mass and population, pulmonary, extrapulmonary and systemic forms of nocardiosis were reported in only 6 of the 26 Brazilian states from 1970 to 2013. A least 33.8% of these 46 cases of nocardiosis proved fatal. Interestingly, coinfection by two clones may occur in patients presenting nocardiosis. Nocardia infection may be more common throughout the Brazilian territory and in other developing tropical countries than is currently recognized and MLSA should be used more extensively as an effective method for Nocardia identification.Author Summary Nocardiosis is an in common and potentially life-threatening infection. Most cases occur in immunocompromised patients, and a delay in establishing the diagnosis is due to the difficulties in clinical diagnosis and in cultivating and detecting Nocardia. Growth of Nocardia species in culture media is slow and incubation should be carried out for at least two weeks to detection this microorganism from clinical specimens. Accordingly, high levels of suspicion on the part of the clinician and of experience on the part of laboratory personnel are essential for detection of nocardiosis. In Brazil, clinical reports of Nocardia infections are scarce and the knowledge of the clinical impact of nocardiosis is fragmentary, suggesting that this genus may be underestimated as a cause of human diseases and/or neglected. In this study conventional biochemical method led to the misidentification of Brazilian isolates. Herein, molecular characterization of four loci was precisely identified as N. nova, N. cyriacigeorgica, N. asiatica and N. exalbida or N. gamkensis species. To the best of our knowledge, these are the first reported cases of human infection due to these Nocardia species in Brazil. Molecular methods offer a time-saving and accurate identification of the Nocardia genus at the species level and thus, play an important role in the diagnosis and treatment of nocardiosis.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

ISOLAMENTO DE AMOSTRAS DO COMPLEXO CORYNEBACTERIUM DIPHTHERIAE POTENCIALMENTE TOXINOGÊNICAS DURANTE A PANDEMIA DA COVID-19 NO BRASIL: UM ALERTA À VIGILÂNCIA EPIDEMIOLÓGICA BRASILEIRA

Introdução/objetivo: A difteria é uma toxiinfecção aguda que se apresenta na forma respiratória e/ou cutânea, e que pode ser fatal devido à ação da toxina diftérica (TD). O principal agente etiológico é Corynebacterium diphtheriae, mas espécies filogeneticamente relacionadas (Corynebacterium ulcerans, Corynebacterium pseudotuberculosis, Corynebacterium belfantii, Corynebacterium rouxii e Corynebacterium silvaticum), que compõem o complexo C. diphtheriae, apresentam o potencial de produzir a TD e, assim, de causar a doença. Importante salientar que amostras atoxinogênicas deste complexo podem a qualquer momento passar a produzir a TD e que algumas destas espécies são patógenos de animais, incluindo animais de companhia, apresentando potencial de transmissão zoonótica. A difteria já foi responsável por muitas epidemias e seu controle foi possível com a introdução da vacinação com o toxóide diftérico na década de 70. Nos últimos anos, surtos foram reportados na República Dominicana, Haiti e Venezuela. Em decorrência da queda da cobertura vacinal contra a difteria e com o avanço da pandemia da COVID-19, em 2021, a Organização Pan-Americana de Saúde e a Organização Mundial de Saúde (OPAS/OMS) reiteraram aos Estados Membros que a vacinação e a vigilância epidemiológica desta doença não fossem interrompidas, e salientaram que um estoque de antitoxina diftérica fosse mantido para controle de possíveis surtos. Neste contexto, este trabalho visa reportar o isolamento, durante o período pandêmico, de amostras do complexo C. diphtheriae a partir de espécimes clínicos de humanos e animais de companhia coletados em diversos estados brasileiros. Métodos: Os isolados, inicialmente processados por um laboratório particular de abrangência nacional, foram enviados para o Laboratório de Difteria e Corinebactérias de Importância Clínica da Universidade do Estado do Rio de Janeiro (LDCIC/UERJ), para confirmação da identificação e investigação da toxinogenicidade pela técnica de mPCR. Resultados: Ao todo, 20 amostras foram isoladas de material clínico, sendo 13 de origem humana e 7 de animal. Os isolados foram identificados como C. diphtheriae (n = 10) e C. ulcerans (n = 10) e caracterizados como atoxinogênicos. Conclusão: Este estudo reforça que as principais espécies de Corynebacterium potencialmente toxinogênicas encontram-se em circulação no Brasil. Assim, enfatizamos que a vigilância epidemiológica da difteria seja contínua e que reservas da antitoxina diftérica sejam mantidas

NJ tree constructed from 3,189-bp concatenated <i>gyrB</i>-16S-<i>secA1</i>-<i>hsp65</i> sequences from seven clinical isolates of <i>Nocardia</i> and those of the most closely related type species.

<p>Distance estimations were calculated by Kimura two-parameter.</p