Milena Dropa

Silent dissemination of colistin-resistant Escherichia coli in South America could contribute to the global spread of the mcr-1 gene.

During a Brazilian multicentric antimicrobial resistance surveillance study, colistin resistance was investigated in 4,620 Enterobacteriaceae isolated from human, animal, food and environmental samples collected from 2000 to 2016. We present evidence that mcr-1-positive Escherichia coli has been emerging in South America since at least 2012, supporting a previous report on the possible acquisition of mcr-1-harbouring E. coli by European travellers visiting Latin American countries.

First Report of the Globally Disseminated IncX4 Plasmid Carrying the mcr-1 Gene in a Colistin-Resistant Escherichia coli Sequence Type 101 Isolate from a Human Infection in Brazil

ABSTRACT 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.

Isolation of KPC-2-producing Klebsiella pneumoniae strains belonging to the high-risk multiresistant clonal complex 11 (ST437 and ST340) in urban rivers

Department of Microbiology, Institute of Biomedical Sciences, Universidade de Sao Paulo, Sao Paulo, SP, Brazil; Department of Clinical Analysis, School of Pharmacy, Universidade de Sao Paulo, Sao Paulo, SP, Brazil; Institute of Biological Sciences, Universidade Federal do Para, Belem, PA, Brazil; School of Public Health, Universidade de Sao Paulo, Sao Paulo, SP, Brazil; Environmental Company of Sao Paulo State (CETESB), Sao Paulo, SP, Brazil

An overview of antimicrobial resistance and its public health significance

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.

Detection of blaCTX-M-type genes in complex class 1 integrons carried by Enterobacteriaceae isolated from retail chicken meat in Brazil.

CTX-M-type extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have been increasingly identified in humans and animals, and their potential transmission by contaminated food has been highlighted. In this study, we report for the first time the isolation of multidrug-resistant (MDR) Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis strains harboring blaCTXM-2 or blaCTXM-8 gene variants in chicken meat sold in markets in southeast Brazil. In this regard, the genetic environment of the blaCTX-M-2 gene is composed of a complex class 1 integron and an ISCR1-associated sequence with dfr and/or aadA gene cassettes located within the variable region. In summary, chicken meat may be a reservoir of MDR Enterobacteriaceae harboring blaCTX-M-type genes, which is a public health concern.

Emergence of Klebsiella pneumoniae carrying the novel extended-spectrum β-lactamase gene variants blaSHV-40, blaTEM-116 and the class 1 integronassociated blaGES-7 in Brazil

A clinical Klebsiella pneumoniae isolate carrying the extended-spectrum beta-lactamase gene variants bla(SHV-40), bla(TEM-116) and bla(GES-7) was recovered. Cefoxitin and ceftazidime activity was most affected by the presence of these genes and an additional resistance to trimethoprim-sulphamethoxazole was observed. The bla(GES-7) gene was found to be inserted into a class 1 integron. These results show the emergence of novel bla(TEM) and bla(SHV) genes in Brazil. Moreover, the presence of class 1 integrons suggests a great potential for dissemination of bla(GES) genes into diverse nosocomial pathogens. Indeed, the bla(GES-7) gene was originally discovered in Enterobacter cloacae in Greece and, to our knowledge, has not been reported elsewhere.

Detection of metallo‐β‐lactamases‐encoding genes in environmental isolates of Aeromonas hydrophila and Aeromonas jandaei

Aims:  To determine the prevalence and expression of metallo‐β‐lactamases (MBL)‐encoding genes in Aeromonas species recovered from natural water reservoirs in southeastern Brazil.

Extended-spectrum beta-lactamases among Enterobacteriaceae isolated in a public hospital in Brazil

Extended-spectrum beta-lactamases (ESBL) in enterobacteria are recognized worldwide as a great hospital problem. In this study, 127 ESBL-producing Enterobacteriaceae isolated in one year from inpatients and outpatients at a public teaching hospital at São Paulo, Brazil, were submitted to analysis by PCR with specific primers for bla SHV, bla TEM and bla CTX-M genes. From the 127 isolates, 96 (75.6%) Klebsiella pneumoniae, 12 (9.3%) Escherichia coli, 8 (6.2%) Morganella morganii, 3 (2.3%) Proteus mirabilis, 2 (1.6%) Klebsiella oxytoca, 2 (1.6%) Providencia rettgeri, 2 (1.6%) Providencia stuartti, 1 (0.8%) Enterobacter aerogenes and 1 (0.8%) Enterobacter cloacae were identified as ESBL producers. Bla SHV, bla TEM and bla CTX-M were detected in 63%, 17.3% and 33.9% strains, respectively. Pulsed field gel eletrophoresis genotyping of K. pneumoniae revealed four main molecular patterns and 29 unrelated profiles. PCR results showed a high variety of ESBL groups among strains, in nine different species. The results suggest the spread of resistance genes among genetically different strains of ESBL-producing K. pneumoniae in some hospital wards, and also that some strongly related strains were identified in different hospital wards, suggesting clonal spread in the institutional environment.

Emergence of carbapenem-resistant Escherichia coli producing CMY-2-type AmpC beta-lactamase in Brazil.

Carbapenem-resistant Escherichia coli isolates have not been described to date in South America. However, the emergence of Shigella flexneri and Klebsiella pneumoniae isolates producing CMY-2type plasmid-mediated AmpC was recently reported in Argentina (Radice et al., 2007; Rapoport et al., 2008). Here, we report the emergence of carbapenemresistant E. coli producing CMY-2-type AmpC b-lactamase in Brazil, confirming that CMY-2-producing strains have already become established in Latin America.

Characterization of Vibrio Parahaemolyticus isolated from oysters and mussels in São Paulo, Brazil

Vibrio parahaemolyticus is a marine bacterium, responsible for gastroenteritis in humans. Most of the clinical isolates produce thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) encoded by tdh and trh genes respectively. In this study, twenty-three V. parahaemolyticus, previously isolated from oysters and mussels were analyzed by PCR using specific primers for the 16S rRNA and virulence genes (tdh, trh and tlh) and for resistance to different classes of antibiotics and PFGE. Nineteen isolates were confirmed by PCR as V. parahaemolyticus. The tlh gene was present in 100% of isolates, the tdh gene was identified in two (10.5%) isolates, whereas the gene trh was not detected. Each isolate was resistant to at least one of the nine antimicrobials tested. Additionally, all isolates possessed the blaTEM-116 gene. The presence of this gene in V. parahaemolyticus indicates the possibility of spreading this gene in the environment. Atypical strains of V. parahaemolyticus were also detected in this study.