Comparison of cell invasion, macrophage survival and inflammatory cytokines profiles between Salmonella enterica serovars Enteritidis and Dublin from Brazil.

AIMS: This study compared the capacity of strains of Salmonella enterica serovars Enteritidis and Dublin isolated in Brazil to invade epithelial cells, to be internalized by and survive within macrophages, and to stimulate cytokine release in vitro. METHODS AND RESULTS: Both serovars infected 75 and 73% Caco-2 (human) and MDBK (bovine) epithelial cells respectively. Salmonella Dublin and S. Enteritidis (i) were internalized at the respective rates of 79·6 and 65·0% (P ≤ 0·05) by U937 (human) macrophages, and 70·4 and 66·9% by HD11 (chicken) macrophages; and (ii) multiplied at the respective rates of 3·2- and 2·7-fold within U937 cells, and 1·9- and 1·1-fold (P ≤ 0·05) within HD11 cells respectively. Seventy per cent of 10 S. Dublin strains stimulated IL-8 production, while 70% of S. Enteritidis strains enhanced production of IL-1ß, IL-6, IL-8, IL-10, IL-12p70 and TNF in Caco-2 cells. CONCLUSIONS: Compared with S. Enteritidis, S. Dublin had stronger ability to survive within macrophages and induced weak cytokine production, which may explain the higher incidence of invasive diseases caused by S. Dublin in humans. SIGNIFICANCE AND IMPACT OF THE STUDY: This study compared S. enterica serovars Enteritidis and Dublin to provide comparative data about the profile of the two serovars in cells from humans, the common host and their respective natural animal hosts and vice versa in order to check the differences between these two phylogenetically closely related serovars that share antigenic properties but present different phenotypic behaviours.

A comprehensive survey of Aeromonas sp. and Vibrio sp. in seabirds from southeastern Brazil: outcomes for public health.

AIMS: To perform a microbiological survey regarding the presence, prevalence and characterization of Aeromonas sp. and Vibrio sp. in debilitated wrecked marine birds recovered from the centre-north coast of the state of Rio de Janeiro, Brazil. METHODS AND RESULTS: Swabs obtained from 116 alive and debilitated wrecked marine birds, comprising 19 species, from the study area were evaluated by biochemical methods. Antimicrobial susceptibility tests and pathogenicity gene screening were performed for bacterial strains of public health importance. Vibrio sp. and Aeromonas sp. were identified, as well as certain pathogenic genes and resistance to selected antimicrobials. CONCLUSIONS: This study demonstrates that the identified bacteria, mainly Vibrio sp., are fairly prevalent and widespread among several species of seabirds and highlights the importance of migratory birds in bacterial dispersion. In addition, it demonstrates the importance of the bacterial strains regarding their pathogenic potential. Therefore, seabirds can act as bacterial reservoirs, and their monitoring is of the utmost importance in a public health context. SIGNIFICANCE AND IMPACT OF THE STUDY: The study comprehensively evaluates the importance of seabirds as bacteria of public health importance reservoirs, since birds comprising several pathogenic bacterial species were evaluated.

Staphylococcus spp. isolated from wild birds apprehended in the local illegal trade in Rio de Janeiro, Brazil, and relevance in public health.

This work aimed to investigate the prevalence of Staphylococcus in wild birds seized in illegal trade and their antimicrobial resistance patterns. Cloacal samples were obtained from 109 wild birds apprehended in the street markets in Rio de Janeiro, Brazil. Staphylococcus spp. were phenotypically and genotypically identified, and resistance profile was evaluated according to Clinical and Laboratory Standards Institute guidelines and by polymerase chain reaction of mecA and blaZ genes. Staphylococcus was detected in 45·9% (50/109) of the cloacal swab samples, and 39 (78·0%) isolates were resistant to one or more of the nine antimicrobials tested and were also positive to mecA (12/39) or blaZ genes (14/39). High percentage of resistance was detected to ampicillin, oxacillin, cefoxitin, clindamycin and tetracycline, with the absence of resistance to vancomycin. Wild birds captured and submitted to captive stress conditions of illegal trade market of Brazil may have an important role as reservoirs of Staphylococcus spp. and its antimicrobial resistance mechanisms. The significance of this study is revealed by the zoonotic and pathogenic potential of staphylococci and that impact to public health and requires monitoring polices of wild birds health in tropical areas. SIGNIFICANCE AND IMPACT OF THE STUDY: The isolation of Staphylococcus species that are not commonly isolated from wild bird faeces, the relatively high proportion of strains showing degrees of resistance to ß-lactamics, lincosamides and tetracycline, and also the presence of mecA and blaZ genes that has been associated with multidrug phenotype reveal its public health relevance and zoonotic potential. Consequently, this represents an important route to transmission of this pathogen and its antimicrobial resistance mechanisms throughout national and international frontiers fostered by the illegal trade of wild animals and close contact with humans.

Comparative genome analysis and characterization of the Salmonella Typhimurium strain CCRJ_26 isolated from swine carcasses using whole-genome sequencing approach.

Salmonella pathogenicity relies on virulence factors many of which are clustered within the Salmonella pathogenicity islands. Salmonella also harbours mobile genetic elements such as virulence plasmids, prophage-like elements and antimicrobial resistance genes which can contribute to increase its pathogenicity. Here, we have genetically characterized a selected S. Typhimurium strain (CCRJ_26) from our previous study with Multiple Drugs Resistant profile and high-frequency PFGE clonal profile which apparently persists in the pork production centre of Rio de Janeiro State, Brazil. By whole-genome sequencing, we described the strain's genome virulent content and characterized the repertoire of bacterial plasmids, antibiotic resistance genes and prophage-like elements. Here, we have shown evidence that strain CCRJ_26 genome possible represent a virulence-associated phenotype which may be potentially virulent in human infection. SIGNIFICANCE AND IMPACT OF THE STUDY: Whole-genome sequencing technologies are still costly and remain underexplored for applied microbiology in Brazil. Hence, this genomic description of S. Typhimurium strain CCRJ_26 will provide help in future molecular epidemiological studies. The analysis described here reveals a quick and useful pipeline for bacterial virulence characterization using whole-genome sequencing approach.

Chicken feet bacteriological quality at 4 steps of technological processing.

The production of chicken feet is primarily intended for foreign markets, and there is still no specific legislation in Brazil that determines the quality standard of these products. The bacteriological quality of chicken feet was evaluated as a product for human consumption at different steps of the technological processes. Eighty broiler feet from 20 lots at 4 steps of processing were collected for quantitative analysis, total count of aerobic mesophilic bacteria, and determining the most probable number of coliforms and fecal coliforms. Thirty-eight pools of 15 broiler feet each from 19 lots were used for qualitative analysis and the isolation of Salmonella enterica spp. and Escherichia coli O157:H7. Escherichia coli O157:H7 was not found in any of the samples. Salmonella spp. were isolated in 68% (13/19) of the lots. The Salmonella Schwarzengrund serotype was found in 12 of the 13 lots of positive samples and the Salmonella Anatum and Salmonella Corvallis serotypes were identified in the remaining lot. Processing is effective in reducing contamination by mesophilic bacteria, coliforms, and Salmonella spp. in these products. This work constitutes the first study in Brazil on microbiological quality of chicken feet.

Incidence and antimicrobial resistance of enteropathogens isolated from an integrated aquaculture system.

AIMS: To evaluate an integrated aquaculture system, microbiological analyses of water used in this system were carried out and the incidence and antimicrobial resistance of enteropathogens were determined in the related ecosystem. METHODS AND RESULTS: Microbiological analysis was undertaken for Salmonella sp., Shigella sp., Vibrio sp. and Aeromonas sp. The disc-diffusion method was performed according to the Clinical and Laboratory Standards Institute. Water samples tested had 32.9% of faecal coliform rates (≤1600 per 100 ml) in accordance with WHO for pisciculture in wastewater. Salmonella spp. were detected in 14.5% of the samples. From a total of 33 strains, 15.1% were resistant to one or two antimicrobial drugs tested and multidrug resistance was not observed. Aeromonas spp. were identified in 91.6% of the samples. From a total of 416 strains, resistance to one antimicrobial class was observed in 66.3% and multidrug resistance in 37.7%. CONCLUSIONS: This system reflects the community profile, drawing attention to the circulation of pathogens, because the genes coding for resistance to classical antibiotics and broad spectrum are a public health problem. SIGNIFICANCE AND IMPACT OF THE STUDY: The reuse of water resources requires continuous monitoring as the system is subject to treatment failure, which can result in the spread of bacterial pathogens.

Antimicrobial resistance and subtyping of Salmonella enterica subspecies enterica serovar Enteritidis isolated from human outbreaks and poultry in southern Brazil.

To investigate antimicrobial resistance, 96 Salmonella enterica subspecies enterica serovar Enteritidis strains isolated from salmonellosis outbreaks and poultry-related products obtained in southern Brazil were analyzed. Macrorestriction patterns, obtained by pulsed-field gel electrophoresis and phage types, were assessed. Although 43.75% of samples were sensitive to all drugs tested, resistance to sulfonamide (34.37%), trimethoprim-sulfamethoxazole (25.00%), nalidixic acid (14.58%), streptomycin (2.08%), gentamicin, and tetracycline (1.04%) was identified. Furthermore, 89.60% of strains belonged to phage type 4, and a predominant pulsed-field gel electrophoresis genotype represented by 82.29% of the strains was identified, suggesting that a clonal group was distributed in poultry, food, and human isolates. Although it was not possible to associate strains from different sources, the occurrence of antimicrobial-resistant Salmonella Enteritidis strains supports the need to establish monitoring programs to identify the emergence of potential resistance patterns and to direct policies for use of these drugs in food-producing animals.

Detection of virulence-associated and regulatory protein genes in association with phage typing of human Vibrio cholerae from several geographical regions of the world.

Vibrio cholerae O1, O139 and occasionally non-O1/non-O139 serogroups are most often responsible for epidemic and pandemic cholera. This study used genotypic patterns of PCR-based detection of virulence-associated and regulatory protein genes, along with phage typing, to characterize 86 V. cholerae strains. Thirty-eight of 53 O1 biotype El Tor strains harboured both tcpA classical and tcpA El Tor genes, and three El Tor strains lacked the V. cholerae O1-specific gene (Vc-O1); three O139 strains contained both Vc-O1 and Vc-O139 genes and seven out of ten non-O1/non-O139 strains possessed the Vc-O1 gene. The latter strains all harboured the virulence-associated genes ctxA, zot, ace, RS1, hlyA, ompU, rtxA and sxt. Two phage types, T27 and T25, were predominant in strains from different geographical regions of India, whereas more variation in phage susceptibility was observed for tetracycline-resistant strains from Kolkata. These results suggest that the pattern and distribution of virulence genes and phage types of V. cholerae are equally useful and discriminatory in tracing the origin of newly emerging strains.

Comparative analysis of methods and models for predicting biochemical methane potential of various organic substrates.

Biochemical methane potential (BMP) corresponds to the maximum methane production at anaerobic digestion infinite time and is a key parameter to evaluate the suitability of substrates to obtain biogas. The main objective of this work is to explore the data available in the literature for ten categories of substrates to compare and develop new methods and mathematical models able to predict BMP. Indeed, experimental procedure is time-consuming, laborious and costly, and the development of methods or models based on properties easily assessed may be very helpful at industrial scale. In this study, three substrates (banana waste, tomato waste and winery wastewater) were tested and compared with >150 results from the literature. The analysis involved four methods (Met_I to Met_IV) and five models developed by multivariate regression (Mod_I to Mod_V). Met_I is related to elemental analysis; Met_II with the organic fraction composition; Met_III is associated with chemical oxygen demand (COD); Met_IV is based on NIR spectra. Regression models are combinations by grouping single variables: C, H, O, N (Mod_I); hemicellulose, lignin (LG), acid detergent fibre (ADF) (Mod_II); volatile solids (VS), COD (Mod_III); proteins (PT), carbohydrates (CRB), lipids (LP) (Mod_IV); and CRB, LP, PT, LG, ADF (Mod_V). The results showed that no significant correlation can be found between BMP and single common properties (e.g. VS or C/N ratio). However, good results may be achieved with models developed by multivariate regression (R2 from 0.93 to 0.98, and R2adj from 0.91 to 0.96). The prediction of BMP based on Met_IV, which is based on NIR spectroscopy combined with a multivariate regression model, revealed to be a promising method for both data from literature as well as for substrates analyzed in the present work.

Genetic diversity, anti-microbial resistance, plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil.

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti-microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA-types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33-year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti-microbial treatments used to control S. Dublin infections in humans in Brazil.

Analysis of some factors involved in the virulence mechanism of Vibrio cholerae non-01.

A study was carried out to evaluate the potential intestinal toxicity of 188 samples of Vibrio cholerae non-01 isolated from seawater found along the beaches of Rio de Janeiro city. Three different assays were carried out involving: (a) detection of vascular permeability factor (PF) in guinea pigs (together with assessment of two culture media for production of the toxin); (b) intestinal fluid accumulation (FA) in suckling mice; and (c) detection of haemolysin. The results demonstrated that both culture media gave a similar level of performance. In the animal assays, 43% of the samples induced PF in guinea pigs, 28.7% caused intestinal fluid accumulation in suckling mice, and 63.28% contained haemolysin. Only 4.25% of the samples gave positive results in all three tests.

Vibrio cholerae resistant to 2,4-diamino-6,7-diisopropylpteridine (O/129) isolated from patients with enteritis in Ceará, Brazil.

This paper reports the characterization of clinical Vibrio cholerae resistant to vibriostatic agent O/129, using classical and plasmid analysis. In a study conducted during December 1991-September 1993, two of 7,058 V. cholerae strains, obtained from patients suspected to have cholera in the State of Ceará, northeast Brazil, were resistant to 150 micrograms of the vibriostatic agent O/129 (2,4-diamino-6,7-diisopropylpteridine). One strain was identified as V. cholerae O1 El Tor Inaba and the other one as serogroup O22. Only one O1 strain harboured a plasmid of 147 kb transferable to Escherichia coli K12, and five strains of V. cholerae O1 and non-O1 were sensitive to O/129 and plasmid-negative at a frequency between 8 x 10(-2) and 3.6 x 10(-5). Additionally, O/129-resistant strains of V. cholerae O1 and O22 were resistant to trimethoprim/sulphamethoxazole.

Microbicidal effect of medicinal plant extracts (Psidium guajava Linn. and Carica papaya Linn.) upon bacteria isolated from fish muscle and known to induce diarrhea in children.

Out of the twenty-four samples of shrimp and fish muscle used for this study, twelve were collected near a large marine sewer for waste disposal, 3 km off the coast of Fortaleza (Brazil) and used for the isolation of E. coli. Other twelve were collected at the Mucuripe fresh fish market (Fortaleza, Brazil) and used for the isolation of Staphylococcus aureus. Ethanol, water and acetone-diluted extracts of guava and papaya leaf sprouts were tested on the bacteria in order to verify their microbicidal potential. The E. coli strains used in the trials were rated LT positive. The papaya leaf extracts (Carica papaya Linn) showed no microbicidal activity while the guava sprout extracts (Psidium guajava Linn) displayed halos exceeding 13 mm for both species, an effect considered to be inhibitory by the method employed. Guava sprout extracts by 50% diluted ethanol most effectively inhibited E. coli (EPEC), while those in 50% acetone were less effective. It may be concluded that guava sprout extracts constitute a feasible treatment option for diarrhea caused by E. coli or by S. aureus-produced toxins, due to their quick curative action, easy availability in tropical countries and low cost to the consumer.

[The relationship among the adaptation modes of Roy and NANDA taxonomy of nursing diagnoses]. / A relação entre os modos adaptativos de ROY e a taxonomia de diagnósticos de enfermagem da NANDA.

The present study is theoretical-reflexive with the purpose to establish a correlation between NANDA's taxonomy diagnoses and the adaptation modes proposed by Roy. Authors defined the relationships among the indicators of positive adaptation, the common problems of adaptation proposed by Roy and NANDA's nursing diagnoses. Results showed a strong correspondence between the existent concepts in the studied theoretical model and NANDA's taxonomy of nursing diagnoses. Authors concluded that there is a possibility of using NANDA's nursing diagnoses and the nursing process based on Roy's Adaptation Theory.

Imagens do ato de amamentar como cuidado em saúde: a percepção das próprias nutrizes / Images of the act of breastfeeding as health care: the perception of the mothers themselves

Objetivo: analisar a percepção das nutrizes sobre o ato de aleitar, a partir da própria imagem fotográfica. Método: estudo qualitativo do tipo descritivo-exploratório, realizado com 10 puérperas numa maternidade de risco habitual. Coleta de dados ocorreu após apresentação das fotografias das próprias nutrizes, amamentando na sala de parto e puerpério, com entrevistas semiestruturadas, realizadas no domicílio das participantes e, posteriormente, estas foram submetidas à análise de conteúdo temática. Resultados: as imagens tridimensionais dessas mulheres vivenciando a lactação, refletiu a rede de cuidados à amamentação no pré-natal, parto e puerpério presente na atuação dos profissionais de saúde, tendo em vista o alcance do sucesso da amamentação. Conclusão: a percepção da nutriz acerca da própria imagem corporal durante o aleitamento, foi considerada a expressão de um momento singular resultante do processo profissional de cuidado em saúde para o sucesso da vivência da amamentação.

Objective: to analyze the mothers' perception of the act of breastfeeding, from the photographic image itself. Method: qualitative study of the descriptive-exploratory type, carried out with 10 puerperal in a maternity unit at usual risk. Data collection occurred after presenting the photographs of the mothers themselves, during breastfeeding in the delivery room and puerperium, using a semi-structured interview conducted in their homes and later, these were submitted to thematic content analysis. Results: the three-dimensional images of these women experiencing lactation reflected the network of breastfeeding care in the prenatal, delivery and puerperium present in the health professionals’ performance, in view of the success of breastfeeding. Conclusion: the nurturers’ perception about her own body image during breastfeeding was considered the expression of a singular moment resulting from the professional process of health care for the success of breastfeeding experience.

Percepção das nutrizes acerca do valor útil do apoio ao aleitamentomaterno / Nurturer’s perception about the useful value of support for breastfeeding

Objetivo: analisar a valoração axiológica da mulher-nutriz quanto ao apoio no processo de lactação.Método: estudo de cunho social, exploratório, descritivo, qualitativo, realizado em maio e junho de2014 no alojamento conjunto de um hospital universitário localizado em um município do Rio deJaneiro. Foram entrevistadas quinze mulheres-nutrizes internadas. Os dados coletados foramsubmetidos à análise de conteúdo na modalidade temática e à Teoria dos Valores, de Max Scheler.Resultados: o valor identificado foi o valor útil do apoio ao aleitamento materno e do seu manejocomo processo para o enfrentamento das dificuldades vivenciadas pelas nutrizes no início daamamentação. Conclusão: a valoração da amamentação é importante estratégia para a atuaçãoprofissional, permitindo intervir direta e eficazmente junto às nutrizes com ações para assegurar osucesso da promoção e do apoio ao aleitamento materno.

Objective: to analyze the axiological value of nurturing woman regarding the Objective: to analyzethe axiological value of female nurturers regarding the support in the breastfeeding process.Methods: this is a Social, exploratory, descriptive, qualitative study, conducted between May andJune 2014 in the joint accommodation of a university hospital in Rio de Janeiro. At the time, fifteenhospitalized nursing mothers were interviewed. The data were subjected to content analysis inthematic modality and Max Scheler's Theory of Values. Results: the useful value of breastfeedingsupport was identified and its management as a process for the confrontation with the difficultiesexperienced by nursing mothers at the early stages of breastfeeding were identified. Conclusion:the valuation of breastfeeding is an important strategy for health professional performance, allowing direct and effective interventional on the mothers with actions to ensure the success of promotion and support to breastfeeding.

Prevalence and identification of Salmonella spp. in water buffaloes from São Paulo State, Brazil / Prevalência e identificação de Salmonella spp. em búfalos do Estado de São Paulo, Brasil

O objetivo do estudo foi investigar a prevalência de Salmonella spp. em amostras de fezes de búfalos do estado de São Paulo, Brasil, e identificar os sorotipos isolados. Foram examinadas 116 amostras de suabes retais de búfalos das raças Jafarabadi e Murrah, coletadas em triplicata, em seis propriedades rurais localizadas nas regiões Central, Centro-Oeste e Nordeste do estado de São Paulo, Brasil. Para avaliar a presença de Salmonella spp., foram utilizados três diferentes caldos de enriquecimento (caldo selenito cistina, caldo tetrationado Muller-Kauffmann e caldo Rappaport-Vassiliadis) e dois diferentes meios de cultura (ágar verde brilhante modificado e ágar XLT4). Das 116 amostras de suabes retais examinadas, oito amostras (6,90%; 8/116) foram positivas para Salmonella spp., incluindo quatro sorotipos: S. Panama (50%; 4/8), S. Agona (25%; 2/8) , S. Newport (12,5%; 1/8) e S. Saintpaul (12,5%; 1/8), todos isolados de búfalos sem sinais clínicos de salmonelose, indicando a importância dos animais assintomáticos como fonte de infecção para outros animais e seres humanos. Das seis propriedades rurais avaliadas, apenas em duas fazendas (33,3%; 2/6) não foi detectada Salmonella spp. O uso de mais de um caldo de enriquecimento seletivo e de mais de um meio de cultura é indicado para o isolamento de Salmonella.(AU)

Sorovares e perfil de suscetibilidade a antimicrobianos em Salmonella spp. isoladas de produtos de origem suína / Serovars and antimicrobial susceptibility of Salmonella spp. product isolated from swine

Foi analisado um total de 1824 cepas de Salmonella, isoladas de alimentos de origem suína, no período de janeiro/2005 a junho/2010. As cepas, provenientes de diferentes regiões do país, foram recebidas pelo Labent/IOC/FIocruz para caracterização antigênica conclusiva. Foram identificados 41 sorovares, destacando-se: Typhimurium, Derby, Enteritidis, Panama, Infantis e Anatum. Aspectos bacteriológicos e epidemiológicos relacionados a esses sorovares foram discutidos. O teste de suscetibilidade aos antimicrobianos foi realizado em 357 amostras, 257 (72%) foram resistentes a uma ou mais drogas, e destas, 31,9% mostraram-se multirresistentes. A variedade de sorovares observada neste estudo confirma o papel dos suínos na cadeia alimentar como importantes reservatórios de Salmonella, agravado ainda pelo elevado percentual de cepas resistentes a um ou mais antimicrobianos, alertando para uma condição de risco à saúde pública.

We analyzed a total of 1824 strains of Salmonella isolated from swine-origin foods from January/2005 to June/2010. The strains from different regions of the country were received by Labent/IOC/FIOCRUZ for conclusive antigenic characterization. We identified 41 serovars, of which these stood out: Typhimurium, Derby, Enteritidis, Panama, Infantis and Anatum. Bacteriological and epidemiological aspects related to these serovars were discussed. The antimicrobial susceptibility test was performed on 357 samples, 257 (72%) were resistant to one or more of these drugs and 31,9% were multiresistant. A variety of serovars were identified reinforcing the swine as an important reservoir of Salmonella in the food chain. The high rates of antimicrobial resistance obtained in this evaluation may represent a risk condition to human health.

Clonality and antimicrobial resistance gene profiles of multidrug- resistant Salmonella enterica serovar infantis isolates from four public hospitals in Rio de Janeiro, Brazil.

In Brazil, Salmonella enterica serovar Infantis resistant to various antimicrobials, including cephalosporins, has been identified as an etiological agent of severe gastroenteritis in hospitalized children since 1994. In this study, 35 serovar Infantis strains, isolated from children admitted to four different Rio de Janeiro, Brazil, hospitals between 1996 and 2001, were characterized by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing in order to determine their genetic relatedness and antimicrobial resistance profiles. Thirty-four serovar Infantis strains were resistant to at least two antibiotic classes, and all 35 strains were susceptible to fluoroquinolones, cephamycin, and carbapenem. Extended-spectrum beta-lactamase (ESBL) screening by double-disk diffusion indicated that 32 serovar Infantis strains (91.4%) produced beta-lactamases that were inhibited by clavulanic acid. Antimicrobial resistance gene profiles were determined by PCR for a subset of 11 multidrug-resistant serovar Infantis strains, and putative ESBLs were detected by isoelectric focusing. Ten serovar Infantis strains carried bla(TEM), catI, ant(3")Ia and/or ant(3")Ib, sulI and/or sulII, and tet(D) genes as well as an integron-associated aac(6')-Iq cassette. Eight strains possessed at least four different beta-lactamases with pI profiles that confirmed the presence of both ESBLs and non-ESBLs. Our PFGE profiles indicated that 33 serovar Infantis strains isolated from Rio de Janeiro hospitals came from the same genetic lineage.

Analysis of some virulence factors of Vibrio vulnificus isolated from Rio de Janeiro, Brazil.

Twenty strains of V. vulnificus isolated from the environment were investigated for characteristics related to their infectivity such as colonial morphology, enzymatic activity and animal assays. The presence of DNase, chitinase, amylase, lecithinase and gelatinase was observed in 100% of the strains, haemolytic activity was absent, and variable results were obtained in elastase, collagenase and chondroitinase. In the animal assays, 70% of the strains were lethal to adult mice, while 45% caused fluid accumulation in suckling mice. Although all strains had opaque colonies, only 3 of the 20 had the three enzymes elastase, collagenase and gelatinase, and only one of these was virulent in animal assays.