Carbapenem-resistant Pseudomonas aeruginosa - clonal spread in Southern Brazil and in the State of Goias

This study evaluated the clonal spread of carbapenem-resistant P. aeruginosa producing SPM-1 type metallo-beta-lactamase (MBL), at the university hospital of Florianopolis, Santa Catarina, Brazil, compared to an epidemic clone previously reported, as well as strains collected in other three Brazilian states. Among the isolates, 17 (62%) were clonal and highly related to strains from other regions of Brazil. Six clonal strains harbored the bla(SPM-1) gene. the finding of a unique SPM-1 producer clone suggests that its dissemination has contributed to the high resistance to carbapenems in Brazilian hospitals.Univ Fed Parana, Hosp Clin, Serv Anal Clin, BR-80060000 Curitiba, Parana, BrazilUniv Fed Santa Catarina, Univ Hosp, Serv Patol Clin, BR-88040900 Florianopolis, SC, BrazilUniversidade Federal de São Paulo, Dept Doencas Infecciosas, São Paulo, BrazilHosp Clin Porto Alegre, Serv Patol Clin, Porto Alegre, RS, BrazilUniv Catolica Goias, Dept Enfermagem, Goiania, Go, BrazilUniv Catolica Goias, Dept Med, Goiania, Go, BrazilFac Pequeno Principe, Inst Pesquisa Pele Pequeno Principe, Curitiba, Parana, BrazilUniversidade Federal de São Paulo, Dept Doencas Infecciosas, São Paulo, BrazilWeb of Scienc

Intraclonal Genome Stability of the Metallo-beta-lactamase SPM-1-producing Pseudomonas aeruginosa ST277, an Endemic Clone Disseminated in Brazilian Hospitals

Carbapenems represent the mainstay therapy for the treatment of serious P aeruginosa infections. However, the emergence of carbapenem resistance has jeopardized the clinical use of this important class of compounds. The production of SPM-1 metallo-beta-lactamase has been the most common mechanism of carbapenem resistance identified in P. aeruginosa isolated from Brazilian medical centers. Interestingly, a single SPM-1-producing P. aeruginosa clone belonging to the ST277 has been widely spread within the Brazilian territory. In the current study, we performed a next-generation sequencing of six SPM-1-producing P. aeruginosa ST277 isolates. The core genome contains 5899 coding genes relative to the reference strain P. aeruginosa PAO1. A total of 26 genomic islands were detected in these isolates. We identified remarkable elements inside these genomic islands, such as copies of the bla(spM-1) gene conferring resistance to carbapenems and a type I-C CRISPR-Cas system, which is involved in protection of the chromosome against foreign DNA. In addition, we identified single nucleotide polymorphisms causing amino acid changes in antimicrobial resistance and virulence-related genes. Together,these factors could contribute to the marked resistance and persistence of the SPM-1-producing P aeruginosa ST277 clone. A comparison of the SPM-1-producing P. aeruginosa ST277 genomes showed that their core genome has a high level nucleotide similarity and synteny conservation. The variability observed was mainly due to acquisition of genomic islands carrying several antibiotic resistance genes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Lab Nacl Comp Cient, Lab Bioinformat, Petropolis, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Internal Med, Lab Alerta,Div Infect Dis, Sao Paulo, BrazilLaboratório Alerta, Division of Infectious Diseases, Department of Internal Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, BrazilCNPq: 305535/2014-5CNPq: 302768/2011-4CNPq: 312864/2015-9FAPERJ: E-26/202.903/2016Web of Scienc

Investigação da resistência aos carbapenêmicos em enterobactérias isoladas em um hospital de Blumenau/SC: detecção laboratorial e aspectos epidemiológicos

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2017.A resistência aos carbapenêmicos por meio da produção de enzimas denominadas carbapenemases tem sido amplamente relatada em espécies pertencentes à família Enterobacteriaceae, estando relacionadas a altas taxas de mortalidade. Neste sentido, o presente trabalho teve por objetivo investigar enterobactérias resistentes a carbapenêmicos (ERC) pelo período de um ano em um hospital de Blumenau (SC), levando em conta os aspectos clínicos, relacionados à internação dos pacientes, e microbiológicos, avaliados por meio de metodologias fenotípicas e genotípicas. Ao término da coleta, foram obtidas 152 amostras isoladas de 147 pacientes, provenientes de swab anal de vigilância, urina, aspirado traqueal e sangue, entre outros sítios em menor proporção. A espécie predominantemente isolada foi Klebsiella pneumoniae (84,2%), seguida das espécies Serratia marcescens (9,9%), Enterobacter cloacae (3,9%), Escherichia coli (1,3%) e Enterobacter aerogenes (0,7%). Os resultados indicam que 55,9% dos isolados caracterizam colonizações, enquanto os demais 43,4% resultaram de processos infecciosos e 0,7% não foram caracterizados quanto à natureza da sua presença. Dos pacientes analisados, 60% apresentaram processos de colonização/infecção com origem na instituição hospitalar analisada, das quais 78% ocorreram quando o paciente se encontrava internado na Unidade de Terapia Intensiva (UTI). Os fatores de risco significativamente relevantes para a obtenção de uma cultura positiva para ERC incluem o uso de instrumentos invasivos (cateteres venosos centrais e vesicais, ventilação mecânica), a realização de procedimentos invasivos e a prévia exposição aos antimicrobianos de amplo espectro do grupo das penicilinas/inibidores de betalactamases. Em relação ao desfecho clínico, 31% dos pacientes vieram a óbito, sendo a utilização de instrumentos invasivos, a realização de procedimentos invasivos, a admissão em UTI e prévias internações fatores significativamente associados à mortalidade dos pacientes. Em relação às enterobactérias isoladas em processos infecciosos, destaca-se o considerável índice de sensibilidade aos aminoglicosídeos amicacina e gentamicina. Já em relação aos isolados bacterianos provenientes de processos de colonização, índices de sensibilidade elevados foram verificados em relação ao antimicrobiano fosfomicina. A pesquisa genotípica para carbapenemases apresentou resultados positivos para o gene blaKPC em 98,6% dos isolados. As metodologias fenotípicas de inibição enzimática e BlueCarba, utilizadas para a pesquisa de carbapenemases, apresentaram, ambas, ótimos resultados de sensibilidade e especificidade quando comparadas à metodologia genotípica PCR. Já a metodologia de tipagem molecular rep-PCR pôde ser aplicada com sucesso na avaliação da clonalidade dos isolados das espécies K. pneumoniae, S. marcescens, E. cloacae e E. coli.Abstract : Resistance to carbapenems mediated by enzymes called carbapenemases has been widely reported in species belonging to the Enterobacteriaceae family, being related to high mortality rates. The present study aimed to investigate carbapenem-resistant Enterobacteriaceae (CRE) for a one year period in a hospital in Blumenau (SC), taking into account the clinical aspects, related to the patients hospitalization, and microbiological aspects, evaluated by phenotypic and genotypic methodologies. By the end of the study, 152 samples from 147 patients were obtained, isolated from surveillance anal swab, urine, tracheal aspirate and blood, among other sites to a lesser extent. The predominant isolated species was Klebsiella pneumoniae (84.2%), followed by Serratia marcescens (9.9%), Enterobacter cloacae (3.9%), Escherichia coli (1.3%) and Enterobacter aerogenes (0.7%). The results indicate that 55.9% of the isolates characterize colonizations, while the remaining 43.4% resulted from infectious processes and 0.7% were not characterized about the nature of their presence. About the analyzed patients, 60% had colonization/infection processes originated in the analyzed hospital institution, of which 78% occurred when the patient was admitted in the Intensive Care Unit (ICU). Significant risk factors related to a positive culture for CRE include the use of invasive instruments (central venous and bladder catheters, mechanical ventilation), invasive procedures and prior exposure to broad spectrum antimicrobial agents from the penicillin/betalactamase inhibitors group. Regarding the clinical outcome, 31% of the patients died. The significant risk factors related to the patients mortality were the use of invasive instruments, invasive procedures, admission to ICU and previous hospitalizations. About the susceptibility profile of the enterobacteria isolated in infectious processes, the sensitivity to aminoglycosides, including amicacin and gentamicin stands out. Regarding the bacterial isolates from colonization processes, a high sensitivity index was verified for the antimicrobial fosfomycin. Genotypic research for carbapenemases showed positive results for the blaKPC gene in 98.6% of the isolates. The phenotypic methodologies of enzymatic inhibition and BlueCarba, used for the research of carbapenemases, presented, both, excellent results of sensitivity and specificity when compared to the genotypic methodology. The rep-PCR molecular typing methodology could be applied successfully for the clonality evaluation of the isolates of K. pneumoniae, S. marcescens, E. cloacae and E. coli