RESUMO

Las bacterias son capaces de desarrollar mecanismos de resistencia a los antimicrobianos, aquellos adquiridos y transmisibles son los más significativos debido al potencial de diseminación. La aparición de Salmonella enterica con resistencia a C3aG, quinolonas y a colistina representa una amenaza progresiva. El objetivo fue determinar la resistencia a los antimicrobianos y la presencia de los mecanismos de resistencia plasmídicos a quinolonas, ß-lactámicos y colistina en aislados de Salmonella provenientes de la vigilancia integrada de enteropatógenos. Fueron estudiadas 501 cepas de Salmonella spp. colectadas entre los años 2020 y 2021, por la red de enteropatógenos del Laboratorio Central de Salud Pública. Se investigó la resistencia a las C3aG, quinolonas y colistina, en aislamientos de humanos, alimentos, animales de consumo y ambiente. Las cepas estudiadas exhibieron resistencia a tetraciclina (32,5%), ácido nalidíxico (29%), ampicilina (13,2%), nitrofurantoína (11,6%), C3aG (7,2%), cotrimoxazol (5,8%), ciprofloxacina (2,2%). El 18% (90/501) presentaron resistencia trasferible por plásmidos, fueron detectados 111 genes (71 cepas con un gen, 17 cepas dos genes y 2 cepas tres genes diferentes). Qnr B: 41,1% (37/90), mcr-1: 38,9% (35/90), CMY: 23,3% (21/90), CTX-M: 16,7% (15/90) y Qnr S: 3,3% (3/90). Heidelberg fue el serovar predominante en muestras de pollo y el mayor portador de genes de resistencia de tipo CMY y mcr-1. La detección de genes en alimentos y animales de consumo, que pueden transmitirse fácilmente al ser humano es motivo de alerta y resalta la importancia de continuar fortaleciendo la vigilancia multisectorial y multidisciplinaria.

Bacteria can develop antimicrobial resistance mechanisms, those acquired and transmissible being the most significant due to the potential for dissemination. The emergence of Salmonella enterica with resistance to third-generation cephalosporins, quinolones, and colistin represents a progressive threat. The objective was to determine antimicrobial resistance and the presence of plasmid resistance mechanisms to quinolones, ß-lactams, and colistin in Salmonella isolates from integrated surveillance of enteropathogens. Five hundred and one strains of Salmonella spp. collected between 2020 and 2021 were studied by the enteropathogen network of the Laboratorio Central de Salud Publica (Central Public Health Laboratory). Research was conducted on the resistance to third-generation cephalosporins, quinolones, and colistin, isolated from humans, foodstuffs, animals for consumption, and the environment. The strains studied exhibited resistance to tetracycline (32.5%), nalidixic acid (29%), ampicillin (13.2%), nitrofurantoin (11.6%), third-generation cephalosporins (7.2%), cotrimoxazole (5.8%), and ciprofloxacin (2.2%). Eighteen percent (90/501) presented plasmid-transferable resistance, 111 genes were detected (71 strains with one gene, 17 strains with two genes, and 2 strains with three different genes). Qnr B: 41.1% (37/90), mcr-1: 38.9% (35/90), CMY: 23.3% (21/90), CTX-M: 16.7% (15/90), and Qnr S: 3.3% (3/90). Heidelberg was the predominant serovar in chicken samples and the largest carrier of CMY and mcr-1 resistance genes. The detection of genes in foodstuffs and animals for consumption, which can be easily transmitted to humans, is a cause for alarm and highlights the importance of continuing to strengthen multisectoral and multidisciplinary surveillance.

RESUMO

Resumen Staphylococcus aureus es una bacteria que coloniza la piel y/o fosas nasales de las personas sanas y produce una amplia gama de infecciones, desde forúnculos hasta las más graves como neumonía o sepsis. La portación nasal de S.aureus parece ser clave en la epidemiologia y la patogenia de la infección. S. aureus se caracteriza por presentar el gen mecA que confiere resistencia a meticilina pudiendo ser sensible a otros antibióticos no betalactámicos. Su virulencia se asocia principalmente a la toxina Leucocidina de Panton Valentine (PVL) una citotoxina que provoca destrucción de los leucocitos y necrosis tisular, lo que a su vez facilita la producción de abscesos. Los objetivos de este estudio fueron, asociar la portación nasal de S. aureus con la forunculosis a repetición, determinar por el método de reacción en cadena de la polimerasa (PCR) los genes que codifican la meticilino resistencia y la toxina PVL. Se estudiaron 128 cepas de S. aureus provenientes de pacientes que estuvieron con o sin tratamiento con antibióticos, y que concurrieron al laboratorio entre 2016 y 2017 con diagnóstico de forunculosis a repetición, de las cuales 74 cepas se aislaron de las lesiones y 54 de sus hisopados nasales. Del total de cepas, se obtuvieron 66,4% de meticilino resistencia y 78,9% presentaron la toxina PVL. Se obtuvo una alta asociación entre la portación nasal de S. aureus de la comunidad con forunculosis a repetición (OR: 5,3 IC95: 1,9 - 14,2%; p = 0,0004< p=0,02; X2)

Abstract Staphylococcus aureus is a bacterium that colonizes the skin and / or nostrils of healthy people and produces a wide range of infections, from forunculosis to the most serious such as pneumonia or sepsis. The nasal carriage of Staphylococcus aureus appear to be key in the epidemiology and pathogenesis of infection. Staphylococcus aureus characterizes by presenting the mecA gene which confers resistance to methicillin and could be sensitive to other non-beta-lactam antibiotics. Its virulence is mainly associated to the Panton-Valentine Leucocidine (PVL) a cytotoxin that causes destruction of the leukocytes and tissue necrosis, which facilitates the abscess production. The objectives of this study were, to associate the nasal carriage of Staphylococcus aureus with recurrent forunculosis, to determine by the polymerase chain reaction method (PCR) the genes encoding methicillin resistance and the toxin PVL. It was studied 128 strains of Staphylococcus aureus from patients with or without antibiotic treatment and went to the laboratory between 2016 and 2017 with recurrent forunculosis, of which 74 strains were isolated from the lesions and 54 from nasal swabs. Of the total strains, 66.4% were methicillin resistance and 78.9% presented PVL toxin. There obtained a high association between the nasal carriage of Staphylococcus aureus of the community with recurrent forunculosis (OR: 5,3 IC95: 1,9 - 14,2%; p = 0,0004< p=0,02; X2).

RESUMO

The present work aimed to study the infection by Perkinsus sp. in the mangrove oysters Crassostrea rhizophorae from the estuary of the Paraíba River (Paraíba State, Brazil). Perkinsosis was detected by incubation of oyster gill pieces in Ray's fluid thioglycollate medium. The monthly prevalence values were all above 70%, thus infection was not likely to be a transient event. Perkinsus sp. parasites isolated from eight oysters were propagated in vitro. PCR-RFLP analysis of in vitro cultured cells as well as the sequences of the rDNA ITS region allowed the identification of the in vitro propagated parasites as Perkinsus marinus. Phylogenetic analyses using rDNA ITS region sequences strongly supported the Perkinsus sp. from Paraíba in a monophyletic group with P. marinus. Thus, the results confirmed the species affiliation of Paraíba Perkinsus sp. as P. marinus. This is the first report of P. marinus in Brazil and South America and the first report of P. marinus naturally infecting C. rhizophorae.

Assuntos

RESUMO

This paper reports the parasites found in three commercially exploited bivalve molluscs (Mytella guyanensis, Anomalocardia brasiliana and Iphigenia brasiliana) of an estuarine region of Ilhéus, south of Bahia, Brazil (14 degrees 48'23''S; 39 degrees 02'47''W). Samples of 20 individuals of each species were collected fortnightly from August 2005 to August 2006. A total of 1480 individuals was collected and processed by standard histologic techniques; the histologic sections were stained with Harris haematoxylin and eosin and examined with light microscope. The water temperature in the study area varied from 24 to 30.5 degrees C and the salinity from 0 to 23ppt. Remarkable differences were found in the parasitic community between the three mollusc species involved in the study, which occupied different habitats in the estuarine region of the Cachoeira river. The following parasites were found: intracellular rickettsia-like colonies in digestive epithelia; intracellular gregarine Nematopsis sp. in gills, mantle, gonad, digestive gland and foot muscle; sporocysts of a Bucephalidae trematode in gonads, mantle, gills, digestive gland and foot; unidentified digenetic metacercariae in digestive gland and gonad; metacestodes of Tylocephalum sp. in connective tissue in the digestive gland and in gonad; and an unidentified metazoan in mantle and intestinal lumen. No significant temporal variation in the prevalence of any parasite was detected, which could be due to the narrow temperature range of the region and the absence of patterns of salinity and rainfall variation through the year. The infestation by sporocyst was the only pathological threat detected for the studied populations because of its potential for host castration. The low infection intensity and/or prevalence of the other parasites and the lack of obvious lesions suggest that there is no other serious pathological risk for the studied mollusc populations.

Assuntos