RESUMO
CTX-M-131 is a natural Asp240Gly variant from the CTX-M-2 group detected in a Providencia rettgeri clinical strain from Brazil. Molecular analysis showed that blaCTX-M-131 was inserted in a complex class 1 integron harbored by a 112-kb plasmid, which has not been previously described as a platform for CTX-M-encoding genes with the Asp240Gly mutation. Steady-state kinetic parameters showed that the enzyme has a typical cefotaximase catalytic profile and an enhanced activity against ceftazidime.
Assuntos
Providencia/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Brasil , Ceftazidima/farmacologia , Integrinas/genética , Cinética , Plasmídeos/genética , beta-Lactamases/metabolismoRESUMO
BACKGROUND: This study aims to scrutinize Salmonella spp. and its serotypes in sewage sludge samples from wastewater treatment plants, and assesses the presence of virulence genes and antibiotics resistant to the profile. Samples (n = 54) were collected and analyzed in accordance with the EPA Method 1682/2006. For positive serological reaction, 40 strains were selected for PCR analyses and detection of spvC, invA and sseL virulence genes, plasmid presence and resistance to antibiotics. RESULTS: Salmonella spp. was detected in 38.9% of the samples collected (<0.006473 to 12.19 MPN/gTS). The most prevalent serotype was Salmonella Infantis. All Salmonella spp. (n = 35) presented at least one of the three virulence genes mentioned above and 40% harboured plasmids. Salmonella Typhimurium strains were isolated harbouring at least one of the following virulence genes: spvC, invA or sseL. Four Salmonella spp. isolates were resistant to tetracycline; three were resistant to trimethoprim-sulfamethoxazole, and one isolate was resistant to ciprofloxacin. Two Salmonella spp. strains presented multi resistance to antimicrobial agents. CONCLUSIONS: The results obtained demonstrated that Salmonella spp. have been found in sewage sludge, thus it is essential to set measures to mitigate human health risks when it is intended to be applied on agricultural soils.
Assuntos
Salmonella/classificação , Salmonella/isolamento & purificação , Esgotos/microbiologia , Agricultura/métodos , Farmacorresistência Bacteriana , Humanos , Plasmídeos/análise , Salmonella/efeitos dos fármacos , Salmonella/genética , Sorotipagem , Fatores de Virulência/genética , Purificação da Água/métodosRESUMO
Yersinia enterocolitica is an important foodborne pathogen that causes illness in humans and animals. Y. enterocolitica is also the most heterogeneous species of the genus and is divided into distinct serotypes and over six biotypes. Y. enterocolitica biotype 1A strains are classically considered as nonpathogenic; however, some biotype 1A isolates have been considered as causative of gastrointestinal disease, yielding symptoms indistinguishable from those produced by pathogenic biotypes. Even after decades of isolation of clinical strains, the pathogenic mechanisms of these isolates are still not fully understood. In the present study, 122 Yersinia enterocolitica biotype 1A strains isolated from swine slaughterhouses and meat markets in Sao Paulo, Brazil, were characterized according to the presence of the virulence genes ail, virF, and ystA. A total of 94 strains were positive to at least one virulence gene (77.05%), and 67 were positive to all of them (54.92%). Twenty-two strains were submitted to PFGE genotyping resulting in 22 distinct pulsotypes, varying from 50% to 84% of genetic similarity. Any clustering tendency among pulsotypes related to origin, isolation site, or even virulence profile was not observed. The present study reports an important contamination of the environment in swine slaughterhouses, meat markets, and pork, by potentially virulent Y. enterocolitica biotype 1A.
Assuntos
Matadouros , Genes Bacterianos , Carne/microbiologia , Yersinia enterocolitica/isolamento & purificação , Animais , Proteínas da Membrana Bacteriana Externa/genética , Toxinas Bacterianas/genética , Técnicas de Tipagem Bacteriana , Brasil , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/genética , Contaminação de Alimentos/análise , Indústria Alimentícia , Variação Genética , Genótipo , Suínos , Transcriptoma , Fatores de Virulência/genética , Yersinia enterocolitica/classificação , Yersinia enterocolitica/genéticaRESUMO
Giardia duodenalis is a protozoan that parasitizes humans and other mammals and causes giardiasis. Although its isolates have been divided into seven assemblages, named A to G, only A and B have been detected in human faeces. Assemblage A isolates are commonly divided into two genotypes, Al and All. Even though information about the presence of this protozoan in water and sewage is available in Brazil, it is important to verify the distribution of different assemblages that might be present, which can only be done by genotyping techniques. A total of 24 raw and treated sewage, surface and spring water samples were collected, concentrated and purified. DNA was extracted, and a nested PCR was used to amplify an 890 bp fragment of the gdh gene of G. duodenalis, which codes for glutamate dehydrogenase. Positive samples were cloned and sequenced. Ten out of 24 (41.6%) samples were confirmed to be positive for G. duodenalis by sequencing. Phylogenetic analysis grouped most sequences with G. duodenalis genotype All from GenBank. Only two raw sewage samples presented sequences assigned to assemblage B. In one of these samples genotype All was also detected. As these assemblages/genotypes are commonly associated to human giardiasis, the contact with these matrices represents risk for public health.
Assuntos
Giardia/classificação , Giardia/genética , Giardíase/parasitologia , Esgotos/microbiologia , Microbiologia da Água , Animais , Brasil , DNA de Protozoário/genética , Genótipo , Giardia/isolamento & purificação , Giardíase/epidemiologia , Glutamato Desidrogenase/genética , Humanos , Dados de Sequência Molecular , Reação em Cadeia da PolimeraseRESUMO
Since Staphylococcus aureus can cause several types of diseases, the development of antibiotic resistance poses an even greater threat to public health. S. aureus is known to possess the adaptive capability to promptly respond to antibiotics, making it resistant and increasingly difficult to treat; methicillin-resistant strains of S. aureus are a major concern with regard to this species. Previous studies reported the identification of methicillin-resistant S. aureus in food, demonstrating that this can represent a source of S. aureus which may carry the mecA gene. Fifty-seven S. aureus isolates, previously obtained from different types of food, were screened by polymerase chain reaction with specific primers for the mecA gene, which mediates methicillin resistance. Five (9%) isolates showed the presence of mecA gene, demonstrating that food may contain microorganisms possessing resistance genes. This study emphasizes the need to include food as a possible source of S. aureus carrying mecA gene and the need to monitor these products. Moreover, this is the first report of the presence of mecA genes in S. aureus isolated from ready-to-eat food in Brazil and Latin America.
Assuntos
Proteínas de Bactérias/genética , Fast Foods/microbiologia , Microbiologia de Alimentos , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Brasil , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Tipagem Molecular , Proteínas de Ligação às Penicilinas , Reação em Cadeia da Polimerase , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificaçãoRESUMO
A high incidence of waterborne diseases is observed worldwide and in order to address contamination problems prior to an outbreak, quantitative microbial risk assessment is a useful tool for estimating the risk of infection. The objective of this paper was to assess the probability of Giardia infection from consuming water from shallow wells in a peri-urban area. Giardia has been described as an important waterborne pathogen and reported in several water sources, including ground waters. Sixteen water samples were collected and examined according to the US EPA (1623, 2005). A Monte Carlo method was used to address the potential risk as described by the exponential dose response model. Giardia cysts occurred in 62.5% of the samples (<0.1-36.1 cysts/l). A median risk of 10⻹ for the population was estimated and the adult ingestion was the highest risk driver. This study illustrates the vulnerability of shallow well water supply systems in peri-urban areas.
Assuntos
Banhos , Ingestão de Líquidos , Giardia/isolamento & purificação , Giardíase/microbiologia , Microbiologia da Água , Abastecimento de Água/análise , Adulto , Brasil/epidemiologia , Giardia/imunologia , Giardíase/epidemiologia , Giardíase/imunologia , Humanos , Medição de Risco/métodos , População Rural , População Suburbana , Fatores de TempoRESUMO
It is known that Aeromonas spp. possess different chromosomal ß-lactamase genes. Presence and phenotypic expression of bla TEM, bla SHV, and bla CTX-M ESBL-encoding genes were investigated in environmental water isolates of Aeromonas hydrophila and Aeromonas jandaei. Presence of bla SHV and bla CTX-M genes was not observed, and bla TEM gene was verified in 91% of the isolates. Sequencing of 10 fragments showed the occurrence of bla TEM-116.
RESUMO
Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.
Assuntos
Animais Domésticos/microbiologia , Animais Selvagens/microbiologia , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , DNA Bacteriano/genética , Escherichia coli Enteropatogênica/classificação , Escherichia coli Enteropatogênica/genética , Animais , Brasil , Análise por Conglomerados , DNA Bacteriano/química , Eletroforese em Gel de Campo Pulsado , Escherichia coli Enteropatogênica/isolamento & purificação , Proteínas de Escherichia coli/genética , Genótipo , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Análise de Sequência de DNA , Sorotipagem , Fatores de Virulência/genéticaRESUMO
Molecular characterization of Cryptosporidium spp.oocysts in clinical samples is useful for public health since it allows the study of sources of contamination as well as the transmission in different geographical regions. Although widely used in developed countries, in Brazil it is restricted to academic studies, mostly using commercial kits for the extraction of genomic DNA, or in collaboration with external reference centers, rendering the method expensive and limited. The study proposes the application of the modifications recently introduced in the method improving feasibility with lower cost. This method was efficient for clinical samples preserved at -20 degrees C for up to six years and the low number of oocysts may be overcome by repetitions of extraction.
Assuntos
Criptosporidiose/diagnóstico , Cryptosporidium/genética , DNA de Protozoário/isolamento & purificação , Fezes/parasitologia , Oocistos , Animais , Protocolos Clínicos , Cryptosporidium/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Cryptosporidium and Giardia are associated with cases of water and foodborne outbreaks in the world. This study included 50 samples of surface raw water collected from two watersheds in the state of São Paulo, Brazil. The isolation of (oo)cysts was performed in accordance with the U.S. Environmental Protection Agency's methods 1623 and genotypic characterization and quantification were carried out by Nested PCR and qPCR assays based on 18S rRNA and gdh genes, respectively. U.S. EPA 1623 method showed the presence of (oo)cysts in 40% ([Formula: see text] = 0.10 oocysts/L) and 100% ([Formula: see text] = 7.6 cysts/L) of samples from São Lourenço River, respectively, and 24% ([Formula: see text] = 0.8 oocysts/L) and 60% ([Formula: see text] = 1.64 cysts/L) of Guarapiranga Reservoir, respectively. The qPCR assay detected C. hominis/parvum in 52% (0.06 to 1.85 oocysts/L) of São Lourenço River and 64% (0.09 to 1.4 oocysts/L) of Guarapiranga Reservoir samples. Presence/absence test for Giardia intestinalis was positive in 92% of São Lourenço River and 8% of Guarapiranga Reservoir samples. The assemblage A was detected in 16% (0.58 to 2.67 cysts/L) in São Lourenço River and no positive samples were obtained for assemblage B in both water bodies. The characterization of anthroponotic species C. parvum/hominis, G. intestinalis, and assemblage A was valuable in the investigation of possible sources of contamination in the watersheds studied confirming the need of expanding environmental monitoring measures for protection of these water sources in our country.
Assuntos
Cryptosporidium/isolamento & purificação , Monitoramento Ambiental/métodos , Giardia/isolamento & purificação , Rios/parasitologia , Animais , Brasil , Cidades , Cryptosporidium/genética , Genótipo , Giardia/genética , Oocistos/isolamento & purificação , RNA Ribossômico 18S/genéticaRESUMO
Nontyphoidal Salmonella (NTS) is a relevant pathogen involved in gastroenteritis outbreaks worldwide. In this study, we determined the capacity to combine the most probable number (MPN) and multiplex polymerase chain reaction (PCR) methods to characterize the most important Salmonella serotypes in raw sewage. A total of 499 isolates were recovered from 27 raw sewage samples and screened using two previously described multiplex PCR methods. From those, 123 isolates were selected based on PCR banding pattern-identical or similar to Salmonella Enteritidis and Salmonella Typhimurium-and submitted to conventional serotyping. Results showed that both PCR assays correctly serotyped Salmonella Enteritidis, however, they presented ambiguous results for Salmonella Typhimurium identification. These data highlight that MPN and multiplex PCR can be useful methods to describe microbial quality in raw sewage and suggest two new PCR patterns for Salmonella Enteritidis identification.
Assuntos
Salmonella enteritidis/genética , Salmonella enteritidis/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex , Probabilidade , SorotipagemRESUMO
Spatial and temporal collections provide important data on the distribution and dispersal of species. Regional-scale monitoring invariably involves hundreds of thousands of samples, the identification of which is costly in both time and money. In this respect, metabarcoding is increasingly seen as a viable alternative to traditional morphological identification, as it eliminates the taxonomic bottleneck previously impeding such work. Here, we assess whether terrestrial arthropods collected from 12 pitfall traps in two farms of a coffee (Coffea arabica L.) growing region of Sao Paulo State, Brazil could differentiate the two locations. We sequenced a portion of the cytochrome oxidase 1 region from minimally processed pools of samples and assessed inter- and intraspecific parameters across the two locations. Our sequencing was sufficient to circumscribe the overall diversity, which was characterized by few dominant taxa, principally small Coleoptera species and Collembola. Thirty-four operational taxonomic units were detected and of these, eight were present in significantly different quantities between the two farms. Analysis of community-wide Beta diversity grouped collections based on farm provenance. Moreover, haplotype-based analyses for a species of Xyleborus beetle showed that there is significant population genetic structuring between the two farms, suggesting limited dispersal. We conclude that metabarcoding can provide important management input and, considering the rapidly declining cost of sequencing, suggest that large-scale monitoring is now feasible and can identify both the taxa present as well as contribute information about genetic diversity of focal species.
Assuntos
Biodiversidade , Coffea , Código de Barras de DNA Taxonômico , Ecossistema , Insetos , Animais , Artrópodes , Brasil , Coffea/crescimento & desenvolvimentoRESUMO
We describe two patients with HIV/AIDS who presented pulmonary and intestinal infection caused by Cryptosporidium parvum, with a fatal outcome. The lack of available description of changes in clinical signs and radiographic characteristics of this disease when it is located in the extra-intestinal region causes low prevalence of early diagnosis and a subsequent lack of treatment.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/parasitologia , Criptosporidiose/parasitologia , Cryptosporidium parvum/isolamento & purificação , Enteropatias Parasitárias/parasitologia , Pneumopatias Parasitárias/parasitologia , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Adulto , Coinfecção , Criptosporidiose/diagnóstico , Cryptosporidium parvum/classificação , Evolução Fatal , Fezes/parasitologia , Feminino , Humanos , Enteropatias Parasitárias/diagnóstico , Pneumopatias Parasitárias/diagnóstico , Pessoa de Meia-IdadeRESUMO
The objectives of the study were to detect and genotype Cryptosporidium spp. and Giardia intestinalis in wastewater samples obtained from five cities with high transit of people in the State of São Paulo, Brazil, and at the entrance of a Wastewater Treatment Plant (WWTP) in Lima, Peru. Samples were collected and concentrated by centrifugation. The genomic DNA was extracted for molecular characterization by nested PCR for Cryptosporidium and double nested PCR for Giardia, followed by sequencing and phylogenetic analysis. G. intestinalis was found in 63.6 % of the samples, and the human assemblages A and B were identified. Cryptosporidium sp. was found in 36.4 % of the samples, and the species were corresponding to Cryptosporidium hominis, Cryptosporidium cuniculus, and Cryptosporidium muris. Results revealed the presence of human pathogenic Cryptosporidium species and G. intestinalis human pathogenic assemblages. Molecular tools highlight the importance to map the genetic diversity of these parasites, as well as to detect their epidemiological circulation pathway in the environment.
Assuntos
Cryptosporidium/isolamento & purificação , Giardia lamblia/isolamento & purificação , Águas Residuárias/parasitologia , Brasil , Cidades , Cryptosporidium/genética , Genótipo , Giardia lamblia/genética , Peru , Filogenia , Reação em Cadeia da Polimerase , RNA de Protozoário/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNARESUMO
INTRODUCTION: CTX-M enzymes are the most prevalent extended-spectrum beta-lactamases (ESBLs) in Brazil and around the world. The spread of CTX-M lies in their ability to be mobilized by insertion sequences and integrons. This study aimed to identify the mobile genetic structures associated with bla(CTX-M) genes from clinical Enterobacteriaceae strains. METHODOLOGY: Twenty-eight clinical non-clonal Enterobacteriaceae were screened by PCR for the presence of bla(CTX-M) genes and class 1 integrase (int1), and for the association of bla(CTX-M) with class 1 integrons. Plasmid incompatibility groups were assessed by PBRT. Wild-type plasmids were transformed into electrocompetent E. coli, and the S1-PFGE technique was used to verify the presence of high-molecular-weight plasmids in both wild-type strains and E. coli transformants. RESULTS: Sequencing showed that strains carried bla(CTX-M-2) (n = 25) and bla(CTX-M-59) (n = 3) genes inserted into the 3'-end of complex class 1 integrons. Thirteen strains also carried bla(TEM) and bla(SHV) genes. CTX-M-2/59-containing complex class 1 integrons were also present in E. coli transformants. The most frequent Inc groups were IncA/C (n = 10) and IncF (n = 8). Heavy plasmids were observed in both wild-type strains and E. coli transformants. CONCLUSIONS: The presence of the same bla(CTX-M-2-group)-containing genetic structure in seven Enterobacteriaceae species isolated at seven hospital wards shows the great mobility potential of complex class 1 integrons. Also, this is the first report of TEM-15, SHV-45, and SHV-55 in Latin America. The genetic environment of bla(CTX-M-2) accounts for their maintenance and spread among Gram-negative bacteria.
Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/isolamento & purificação , beta-Lactamases/genética , Proteínas de Bactérias/classificação , Brasil/epidemiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Primers do DNA , DNA Bacteriano/análise , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/microbiologia , Humanos , Reação em Cadeia da Polimerase , beta-Lactamases/classificaçãoRESUMO
Vibrio fluvialis is a halophilic bacterium found in many environments and is mainly associated with sporadic cases and outbreaks of gastroenteritis in humans. Here, we describe the genome sequences of environmental strains of V. fluvialis 560 (Vf560) and V. fluvialis 539 (Vf539) possessing a variant of the integrative and conjugative element (ICE) SXT for the first time in Brazil and South America.
RESUMO
Multiple papers have been published regarding the bacterial resistance theme over the last years. A variety of information has reached general and scientific public, daily bringing up data on new resistant microorganisms, new drugs, outbreaks, epidemiological news, resistance gene dissemination, and the lack of information in a particular field has caught our attention: the public health department. Most of researchers, physicians and government employees interpret the public health field as a separate department, not linked to this antibiotic resistance era that we are living nowadays. In this paper we carefully tried to fill in the blanks between public health and the bacteria resistance issue, also considering historical, social, economical and biological problematic that come with this possible pre-antibiotic era.
Assuntos
Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana , Saúde Pública , Antibacterianos/farmacologia , HumanosRESUMO
In the last decade, atypical Listeria monocytogenes and L. innocua strains have been detected in food and the environment. Because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. In this study, we performed phenotypic and genotypic characterization of atypical L. monocytogenes and L. innocua isolates obtained from swine slaughterhouses and meat markets. Forty strains were studied, including isolates of L. monocytogenes and L. innocua with low-hemolytic activity. The isolates were characterized using conventional phenotypic Listeria identification tests and by the detection and analysis of L. monocytogenes-specific genes. Analysis of 16S rRNA was used for the molecular identification of the Listeria species. The L. monocytogenes isolates were positive for all of the virulence genes studied. The atypical L. innocua strains were positive for hly, plcA, and inlC. Mutations in the InlC, InlB, InlA, PI-PLC, PC-PLC, and PrfA proteins were detected in the atypical isolates. Further in vitro and transcriptomic studies are being developed to confirm the role of these mutations in Listeria virulence.
Assuntos
Matadouros , Microbiologia de Alimentos , Genótipo , Listeria monocytogenes , Carne/microbiologia , Mutação , Fatores de Virulência/genética , Animais , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , SuínosRESUMO
Vibrio cholerae O1 is the causative agent of cholera and is ubiquitous in the aquatic environment, while V. cholerae strains non-O1 and non-O139 are recognized as causative agents of sporadic and localized outbreaks of diarrhea. Here, we report the complete sequence of a non-O1 and non-O139 V. cholerae strain (VCC19), which was isolated from the environment in Brazil. The sequence includes the integrative conjugative element (ICE). This paper is the first report of the presence of such an element in a V. cholerae strain isolated in Brazil.