ABSTRACT
Introduction:Staphylococcus aureus may provoke peritonitis and death, especially in immunocompromized individuals such as diabetic patients. We evaluated the role of insulin in S. aureus-induced peritoneal infection in diabetic and non-diabetic rats. Materials/Methods: Alloxan-diabetic male Wistar rats and their respective controls received intraperitoneal injections of different strains of S. aureus or sterile phosphate-buffered saline. After 3 days of infection, the first set of diabetic and non-diabetic rats received 4 and 1 IU, respectively, of neutral protamine Hagedorn insulin and were analyzed 8 h later. The second set of diabetic and non-diabetic rats received 4 and 1 IU, respectively, of insulin 2 h before intraperitoneal infection and a half dose of insulin at 5 p.m. for the next 2 days and were analyzed 16 h later. The following measurements were performed: (a) number of cells in the peritoneal lavage fluid (PeLF), white blood cell count, and blood glucose; (b) serum insulin and corticosterone; (c) cytokine levels in the PeLF; (d) expression of adhesion molecules in the vascular endothelium; and (e) microbicidal activity. Results: Diabetic rats showed an increased number of polymorphonuclear leukocytes (PMNs) and increased concentrations of CINC-1, IL-4, and IFN-γ in the PeLF after infection with the ATCC 25923 or N315 αHL+ strain. The mesenteric expression of PECAM-1 was increased after infection with the N315 HLA+ strain. ICAM-1 expression was increased with ATCC infection. Treatment of diabetic rats with a single dose of insulin restored CINC-1 levels in the PeLF for both strains; however, PMN migration, IL-4, and IFN-γ were restored in rats infected with the ATCC strain, whereas the PeLF concentrations of CINC-2, IL-1ß, and IL-4 were increased in N315-infected animals. Insulin restored PMN migration and CINC-2 levels in the PeLF in ATCC-infected rats. After multiple treatments with insulin, the levels of IL-1ß, IL-6, and IFN-γ were increased in the PeLF of diabetic rats after infection with either strain, and CINC-2 levels were restored in N315-infected animals. Conclusion: These results suggest that insulin distinctively modulates cytokine production or release, PMN leukocyte migration, and adhesion molecule expression during the course of peritonitis induced by different strains of S. aureus.
Subject(s)
Cell Adhesion Molecules/genetics , Cytokines/genetics , Gene Expression Regulation , Immunocompromised Host , Staphylococcal Infections/genetics , Staphylococcus aureus/physiology , Animals , Cell Adhesion Molecules/metabolism , Cell Count , Cytokines/metabolism , Diabetes Mellitus, Experimental , Immunity, Innate , Immunohistochemistry , Inflammation Mediators/metabolism , Insulin/metabolism , Insulin/pharmacology , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/pathology , Male , Peritoneal Lavage , Rats , Staphylococcal Infections/immunology , Staphylococcal Infections/metabolism , Staphylococcal Infections/microbiologyABSTRACT
We report changes in the molecular epidemiology of vanA-containing Enterococcus during the intra and interhospital spread of high-risk clones, in Southeastern Brazil. While VRE faecalis predominated during 1998 to 2006, a reversal has been observed in the last years, where VRE faecium belonging to ST114, ST203, ST412, ST478 and ST858 have become endemic.
Subject(s)
Cross Infection/epidemiology , Gram-Positive Bacterial Infections/epidemiology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/genetics , Brazil/epidemiology , Cross Infection/microbiology , Enterococcus faecalis/drug effects , Enterococcus faecalis/genetics , Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/microbiology , Hospitals , Humans , Microbial Sensitivity Tests/methods , Molecular Epidemiology/methods , Vancomycin Resistance/drug effectsSubject(s)
Drug Resistance, Bacterial , Enterococcus faecalis/enzymology , Enterococcus faecalis/isolation & purification , Gram-Positive Bacterial Infections/veterinary , tRNA Methyltransferases/genetics , Animals , Anti-Bacterial Agents/pharmacology , Brazil , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Enterococcus faecalis/classification , Enterococcus faecalis/genetics , Gram-Positive Bacterial Infections/microbiology , Molecular Typing , Polymerase Chain Reaction , Ribosomal Proteins/genetics , Sequence Analysis, DNA , SwineABSTRACT
A colistin-resistant Escherichia coli strain was recovered from a patient with a diabetic foot infection in Brazil. Whole-genome analysis revealed that the E. coli isolate belonged to the widespread sequence type (ST) 101 and harbored the mcr-1 gene on an IncX4 plasmid that was highly similar to mcr-1-bearing IncX4 plasmids that were recently identified in Enterobacteriaceae from food, animal, and human samples recovered on different continents. These results suggest that self-transmissible IncX4-type plasmids may represent promiscuous plasmids contributing to the intercontinental spread of the mcr-1 gene.
Subject(s)
Colistin/pharmacology , Drug Resistance, Bacterial/genetics , Escherichia coli Proteins/genetics , Escherichia coli/drug effects , Escherichia coli/isolation & purification , Aged , Brazil , Drug Resistance, Bacterial/drug effects , Escherichia coli/genetics , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Humans , Male , Microbial Sensitivity Tests , Plasmids/drug effects , Plasmids/geneticsSubject(s)
Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Chickens/microbiology , Enterococcus faecalis/classification , Enterococcus faecium/classification , Meat/microbiology , Animals , Anti-Bacterial Agents , Brazil , Food Contamination , Food Microbiology , Microbial Sensitivity TestsSubject(s)
Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Enterococcus faecium/classification , Enterococcus faecium/isolation & purification , Genotype , Rivers/microbiology , Vancomycin-Resistant Enterococci/classification , Vancomycin-Resistant Enterococci/isolation & purification , Anti-Bacterial Agents/pharmacology , Brazil , Enterococcus faecium/genetics , Hospitals , Humans , Microbial Sensitivity Tests , Molecular Typing , Vancomycin-Resistant Enterococci/geneticsABSTRACT
We report the whole-genome sequence (WGS) of an in vitro susceptible derivative revertant mutant from a bloodstream isolate involved in a nosocomial outbreak in Brazil. The WGS comprises 2.5 Mb with 2,500 protein-coding sequences, 16rRNA genes, and 60 tRNA genes.
ABSTRACT
Pseudomonas aeruginosa is an important cause of infection, especially in immunocompromised patients. In this regard, strains producing carbapenemases, mainly metallo-ß-lactamases (MBLs), have become a significant public health concern. Here, we present the complete annotated genome sequence (65.7 kb) of an F8-related lytic myovirus (Pbunalikevirus genus) that infects MBL-producing P. aeruginosa strains.
Subject(s)
Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/isolation & purification , Rivers/microbiology , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Cities , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Genotype , Humans , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Molecular Sequence Data , Multilocus Sequence Typing , Plasmids , beta-Lactamases/geneticsABSTRACT
Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr) locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high - 77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.
Subject(s)
Bacterial Proteins/genetics , Carrier State/veterinary , Mastitis/veterinary , Sheep Diseases/microbiology , Staphylococcal Infections/veterinary , Staphylococcus aureus/genetics , Trans-Activators/genetics , Virulence Factors/genetics , Animals , Brazil , Carrier State/microbiology , Genes , Genotype , Mastitis/microbiology , Milk/microbiology , Sheep , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Staphylococcus aureus/isolation & purificationSubject(s)
Acetamides/pharmacology , Bacterial Proteins/metabolism , Mutation , Oxazolidinones/pharmacology , RNA, Ribosomal, 23S/metabolism , Ribosomal Proteins/metabolism , Staphylococcus hominis/drug effects , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Brazil , Drug Resistance, Multiple, Bacterial , Genes, Bacterial , Humans , Intensive Care Units , Linezolid , Microbial Sensitivity Tests , RNA, Ribosomal, 23S/genetics , Ribosomal Proteins/genetics , Ribosomes/genetics , Ribosomes/metabolism , Staphylococcal Infections/diagnosis , Staphylococcus hominis/genetics , Staphylococcus hominis/isolation & purification , Tertiary Care CentersABSTRACT
Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr)locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high -77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.
Subject(s)
Animals , Bacterial Proteins/genetics , Carrier State/veterinary , Mastitis/veterinary , Sheep Diseases/microbiology , Staphylococcal Infections/veterinary , Staphylococcus aureus/genetics , Trans-Activators/genetics , Virulence Factors/genetics , Brazil , Carrier State/microbiology , Genes , Genotype , Mastitis/microbiology , Milk/microbiology , Sheep , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Staphylococcus aureus/isolation & purificationSubject(s)
Acetamides/pharmacology , Anti-Bacterial Agents/pharmacology , Cross Infection/microbiology , Mutation , Oxazolidinones/pharmacology , RNA, Ribosomal, 23S/genetics , Staphylococcal Infections/microbiology , Staphylococcus haemolyticus/drug effects , Brazil , Catheter-Related Infections/microbiology , Catheter-Related Infections/transmission , Catheters/microbiology , Cross Infection/transmission , Drug Resistance, Multiple, Bacterial , Electrophoresis, Gel, Pulsed-Field , Humans , Linezolid , Microbial Sensitivity Tests , Sequence Analysis, DNA , Staphylococcal Infections/transmission , Staphylococcus haemolyticus/geneticsSubject(s)
Acetamides/pharmacology , Anti-Bacterial Agents/pharmacology , Cross Infection/epidemiology , Drug Resistance, Bacterial , Oxazolidinones/pharmacology , RNA, Ribosomal, 23S/genetics , Staphylococcal Infections/epidemiology , Staphylococcus epidermidis/drug effects , Brazil , Cross Infection/microbiology , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Hospitals , Humans , Linezolid , Microbial Sensitivity Tests , Molecular Epidemiology , Molecular Typing , Point Mutation , Staphylococcal Infections/microbiology , Staphylococcus epidermidis/isolation & purificationABSTRACT
OBJECTIVE: The aim of this study was to characterize Staphylococcus aureus (MRSA) carriage in a dermatology unit. METHODS: This was a prospective and descriptive study. Over the course of 26 weeks, surveillance cultures were collected weekly from the anterior nares and skin of all patients hospitalized in a 20-bed dermatology unit of a tertiary-care hospital. Samples from healthcare workers (HCWS) were cultured at the beginning and end of the study. Colonized patients were put under contact precautions, and basic infection control measures were enforced. Staphylococcus aureus colonization pressure was determined monthly. Colonized and non-colonized patients were compared, and isolates were evaluated for antimicrobial susceptibility, SCCmec type, virulence factors, and type. RESULTS: Of the 142 patients evaluated, 64 (45%) were colonized by MRSA (39% hospital acquired; 25% community acquired; 36% indeterminate). Despite isolation precautions, hospital-acquired Staphylococcus aureus occurred in addition to the continuous entry of Staphylococcus aureus from the community. Colonization pressure increased from 13% to 59%, and pemphigus and other bullous diseases were associated with MRSA colonization. Eleven out of 71 HCWs (15%) were Staphylococcus aureus carriers, although only one worker carried a persistent clone. Of the hospital-acquired MRSA cases, 14/28 (50%) were SCCmec type IV (3 PFGE types), 13 were SCCmec type III (46%), and one had an indeterminate type. These types were also present among the community-acquired Staphylococcus aureus isolates. SSCmec type IV isolates were shown to be more susceptible than type III isolates. There were two cases of bloodstream infection, and the pvl and tst virulence genes were absent from all isolates. CONCLUSIONS: Dermatology patients were colonized by community- and hospital-acquired Staphylococcus aureus. Half of the nosocomial Staphylococcus aureus isolates were SCCmec type IV. Despite the identification of colonized patients and the subsequent contact precautions and room placement, Staphylococcus aureus colonization continued to occur, and colonization pressure increased. Pemphigus and other bullous diseases were associated with Staphylococcus aureus.
Subject(s)
Carrier State/microbiology , Cross Infection/microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/microbiology , Adult , Anti-Bacterial Agents/pharmacology , Community-Acquired Infections/microbiology , Dermatology , Electrophoresis, Gel, Pulsed-Field , Female , Humans , Male , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Prospective StudiesABSTRACT
Relatos mundiais têm documentado a problemática da endemicidade de isolados clínicos de Pseudomonas aeruginosa multirresistente (MDR) aliada a elevados índices de morbidade/mortalidade. No Brasil, surtos de infecção ocasionados por P. aeruginosa têm sido relacionados com uma disseminação clonal da espécie. Atualmente, as opções terapêuticas para o tratamento das infecções causadas por esse microrganismo são limitadas, muitas vezes restringindo-se ao uso de carbapenêmicos (p. ex., imipenem [IPM]). Assim, a resistência ao IPM é uma questão de saúde pública, uma vez que esse antibiótico é empregado como último recurso no tratamento de infecções de origem hospitalar, causadas por bactérias Gram-negativas multirresistentes. No Brasil, os principais mecanismos relacionados com fenótipos multirresistentes de P. aeruginosa são produção de metalobetalactamase (MBL) do tipo SPM-1, presença de metilase 16S rRNA RmtD, perda de porina OprD e superexpressão de bombas de efluxo, o que pode explicar os altos índices de resistência a carbapenêmicos e aminoglicosídeos. A emergência de cepas com essas características é preocupante, tendo em vista a escassez de terapias efetivas no tratamento de infecções por esse patógeno. Finalmente, com base em relatos nacionais, publicados por diferentes grupos de pesquisa, podemos deduzir que a convergência de múltiplos mecanismos de resistência em P. aeruginosa tem sido um evento favorável para a seleção de diferentes clones endêmicos multirresistentes disseminados no Brasil.
Global reports have documented the endemicity of multidrug-resistant (MDR) Pseudomonas aeruginosa associated with high levels of morbidity/mortality. In Brazil, outbreaks of MDR P. aeruginosa have been related to clonal dissemination. Currently, therapeutic options for the treatment of these infections are restricted to carbapenemic antibiotics (i.e., imipenem [IPM]). Thus, carbapenem resistance is a public health issue, since carbapenems are considered the last resort to nosocomial infections caused by MDR Gram-negative bacteria. In Brazil, the main mechanisms associated with MDR P. aeruginosa phenotypes are metallo-betalactamase (MBL) production (SPM-1 enzyme), presence of 16S rRNA methylase RmtD, loss of OprD porin, and overexpression of efflux pumps, which may explain the high level of carbapenem and aminoglycoside resistance. Accordingly, the emergence and dissemination of MDR strains is worrisome. Finally, based on national reports published by different groups of investigators, it is deduced that the convergence of multiple mechanisms of P. aeruginosa resistance has played a major role in the selection of endemic MDR clones widespread in Brazil.
Subject(s)
Drug Resistance, Bacterial , Endemic Diseases , Porins , Pseudomonas aeruginosaABSTRACT
Staphylococcus aureus is one of the most important infectious mastitis causative agents in small ruminants. In order to know the distribution of Staph. aureus strains associated with infectious mastitis in flocks of sheep in the northeast of Brazil and establish whether these clones are related to the strains distributed internationally, this study analysed the genetic diversity of Staph. aureus isolates from cases of clinical and subclinical mastitis in ewes by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). In this research, 135 ewes with mastitis from 31 sheep flocks distributed in 15 districts were examined. Staph. aureus was isolated from sheep milk in 9 (29%) out of 31 herds located in 47% of the districts surveyed. MLST analysis allowed the identification of four STs (ST750, ST1728, ST1729 and ST1730). The last three with their respective novel alleles (glp-220; pta-182 and yqil-180) were recently reported in the Staph. aureus MLST database (http://www.mlst.net). Each novel allele showed only a nucleotide different from those already described. The occurrence of CC133 (ST750 and ST1729) in this study is in agreement with other reports that only a few clones of Staph. aureus seem to be responsible for most cases of mastitis in dairy farms and that some of these clones may have broad geographic distribution. However, the prevalence of CC5 (ST1728 and ST1730)--an important group related to cases of colonization or infection in humans--differs from previous studies by its widespread occurrence and may suggest human contamination followed by selective pressures of the allelic diversifications presented for these STs.