RESUMO
In Argentina, NDM metallo-ß-lactamase was first reported in 2013. By now, it has disseminated throughout the country in diverse Gram negative bacteria. Here, we report the case of a paediatric patient that underwent a 1-year hospitalisation due to erythrodermic psoriasis in 2014 and received multiple antimicrobial treatments. During his stay, five isolates were obtained from rectal swabs (rs) or blood culture (bc) suspicious of carbapenemase production: a K. quasipneumoniae subsp. quasipneumoniae (rs), Citrobacter freundii (rs), Escherichia coli (bc), Enterobacter cloacae (rs), and a Serratia marcescens (bc). The isolates were studied with broth microdilution, biparental conjugation and plasmid and whole genome sequencing (Illumina). All isolates harboured an 138,998-bp type 1 IncC plasmid that carried blaNDM-1, bleMBL, blaCMY-6, rmtC, aac(6')-Ib, and sul1 resistance genes. Additionally, the blaNDM-plasmids contained ISKpn8 an insertion sequence previously described as associated only to blaKPC. One isolate, a colistin-resistant E. coli, also carried a mcr-1-containing an IncI2 plasmid, which did not harbour additional resistance. The whole genome of K. quasipneumoniae subsp. quasipneumoniae isolate was fully sequenced. This isolate harboured, additionally to blaNDM, three plasmid-mediated quinolone resistance genes: qnrB4, qnrB52 and aac(6')-Ib-cr1. The E. cloacae isolate also harboured qnrA1. These findings alert to the underestimated horizontal dissemination of multidrug-resistant plasmids limiting treatment options with last resort antimicrobials.
Assuntos
Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Plasmídeos/genética , Antibacterianos/farmacologia , Criança , Pré-Escolar , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/classificação , Enterobacteriaceae/efeitos dos fármacos , Escherichia coli/genética , Transferência Genética Horizontal , Hospitais , Humanos , Filogenia , Psoríase/microbiologiaRESUMO
The worldwide dissemination of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae ST258 demands a rapid PCR-based typing method to detect unique genes of the ST258 clone. This study evaluates a PCR developed by Adler et al. (2014) for the detection of ST258 in K. pneumoniae clinical isolates centered on the identification of the pilv-I and prp genes. We tested 143 clinical isolates from Argentina (n=109), Chile (n=1), Colombia (n=1), Costa Rica (n=2), Ecuador (n=5), El Salvador (n=2), Nicaragua (n=5), Panamá (n=2), Paraguay (n=2), Perú (n=3) and Trinidad and Tobago (n=11) recovered from 2006 to 2015. blaKPC, pilv-l and prp genes were detected by PCR and sequenced by standard procedures. ST258 and non-ST258 were defined by PFGE and/or MLST. Isolates were grouped according to PFGE patterns: 58 were compatible with ST258 (group 1) and 85 with non-ST258 (group 2). MLST study was done on an arbitrary selection of isolates. The pilv-l gene was present only in ST258 isolates, regardless of the presence of the blaKPC gene. Results for the prp gene were variable. Its presence did not define ST258. The pilv-I PCR had a sensitivity and specificity of 100%, respectively, for the detection of ST258 in the isolates under investigation. Given our findings, the pilv-I PCR could replace more time and resource consuming methods, allowing for more rapid detection of the circulating high risk K. pneumoniae clone ST258 in Latin American (LA) countries.
Assuntos
Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Reação em Cadeia da Polimerase/métodos , Proteínas de Bactérias/genética , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/isolamento & purificação , América do Sul/epidemiologia , beta-Lactamases/genéticaRESUMO
This study investigated the molecular characteristics of six blaKPC-positive Enterobacteriaceae recovered from three patients in Argentina. Antimicrobial susceptibility testing was performed following Clinical and Laboratory Standards Institute (CLSI) 2014 recommendations. Molecular characterisation of the isolates was performed by biparental conjugation, PCR, sequencing, S1 nuclease restriction, and Southern blot hybridisation with a blaKPC probe using standard protocols and conditions. The isolates studied were as follows. Case 1: Escherichia coli (ECO-P1) and Klebsiella pneumoniae (KPN-P1) isolated from a rectal swab harboured blaKPC-2 in transposon Tn4401a on non-typeable and non-conjugative plasmids. Case 2: Enterobacter cloacae (ECL-P2) and K. pneumoniae (KPN-P2) were isolated from two blood cultures. blaKPC-2 was found in a novel genetic variant of ISKpn8-blaKPC-2-ISKpn6-like on conjugative plasmids of IncL/M type. Case 3, Citrobacter freundii (CFR-P3) and Klebsiella oxytoca (KOX-P3) were isolated from skin and skin-structure infection. The blaKPC gene was detected on ISKpn8-ΔblaTEM-blaKPC-2-ISKpn6-like located on an IncA/C conjugative plasmid. CFR-P3 and KOX-P3 harboured blaPER-2 in addition to the blaKPC gene. In conclusion, we document the horizontal dissemination of blaKPC-2 from diverse Enterobacteriaceae clinical isolates with different genetic backgrounds. This is the first report of E. coli harbouring blaKPC associated with Tn4401a in Argentina.
RESUMO
Two genetically related Klebsiella pneumoniae strains carrying OXA-type carbapenemases were isolated from a single patient 1 month apart. Kpn163 harboured OXA-163 and Kpn247 a new variant named OXA-247 that showed susceptibility to carbapenems and expanded-spectrum cephalosporins similar to OXA-48. Our epidemiological, biochemical and molecular results suggest the intrapatient emergence of blaOXA -247 from blaOXA -163.
Assuntos
Proteínas de Bactérias/genética , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Resistência beta-Lactâmica , beta-Lactamases/genética , Adolescente , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , Cefalosporinas/farmacologia , DNA Bacteriano/química , DNA Bacteriano/genética , Feminino , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Dados de Sequência Molecular , Análise de Sequência de DNA , beta-Lactamases/metabolismoRESUMO
The present work describes the abrupt emergence of Klebsiella pneumoniae carbapenemase (KPC) and characterizes the first 79 KPC-producing enterobacteria from Argentina (isolated from 2006 to 2010). The emergence of bla(KPC-2) was characterized by two patterns of dispersion: the first was the sporadic occurrence in diverse enterobacteria from distant geographical regions, harbouring plasmids of different incompatibility groups and bla(KPC-2) in an unusual genetic environment flanked by ISKpn8-Δbla(TEM-1) and ISKpn6-like. bla(KPC-2) was associated with IncL/M transferable plasmids; the second was the abrupt clonal spread of K. pneumoniae ST258 harbouring bla(KPC-2) in Tn4401a.
Assuntos
Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Conjugação Genética , Elementos de DNA Transponíveis , Enterobacter/genética , Genes Bacterianos , Hospitais , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Tipagem de Sequências Multilocus , Plasmídeos/genéticaRESUMO
We evaluated the ability of the combination disk test (CDT) and the Modified Hodge Test (MHT) to discriminate between various carbapenemase-producing Pseudomonas aeruginosa isolates (KPC, n = 36; metallo-ß-lactamase (MBL), n = 38) and carbapenemase non-producers (n = 75). For the CDT, the optimal inhibitor concentrations and cut-off values were: 600 µg of 3-aminophenylboronic acid (APB) per disk (an increment of ≥4 mm), 1000 µg of dipicolinic acid (DPA) per disk (an increment of ≥5 mm) and 3000 µg of cloxacillin per disk (an increment of ≥3 mm). APB had excellent sensitivity (97%) and specificity (97%) for the detection of KPC enzymes. DPA detected MBL enzymes with a sensitivity and specificity of 97% and 81%, respectively. The MHT resulted in a low sensitivity (78%) and specificity (57%). The CDT could be very useful in daily practice to provide fast and reliable detection of KPC and MBL carbapenemases among P. aeruginosa isolates.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Pseudomonas aeruginosa/enzimologia , Tienamicinas/farmacologia , beta-Lactamases/metabolismo , Proteínas de Bactérias/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Cloxacilina/farmacologia , Humanos , Meropeném , Ácidos Picolínicos/farmacologia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/efeitos dos fármacos , Sensibilidade e Especificidade , beta-Lactamases/efeitos dos fármacosAssuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter/efeitos dos fármacos , Acinetobacter/enzimologia , beta-Lactamases/metabolismo , Infecções por Acinetobacter/epidemiologia , Argentina/epidemiologia , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Estudos RetrospectivosAssuntos
Disenteria Bacilar/epidemiologia , Disenteria Bacilar/microbiologia , Plasmídeos/genética , Shigella flexneri/genética , beta-Lactamases/genética , Argentina/epidemiologia , Resistência às Cefalosporinas , Cefamicinas/farmacologia , Eletroforese em Gel de Poliacrilamida , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Genes Bacterianos/genética , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
An 80-kDa Trypanosoma cruzi urinary antigen (UAg) was affinity-purified from the urine of infected dogs. We demonstrated that UAg is structurally and functionally related to proteins belonging to the transferrin family, as shown by amino acid sequence and iron binding experiments. Nevertheless, monoclonal antibodies raised against UAg specifically and selectively recognized this parasite's circulating antigen. The existence of an 80-kDa T. cruzi antigen co-migrating with UAg could be confirmed when epimastigotes were metabolically labelled with [35S] methionine and then immunoprecipitated with the above mentioned antibodies. We conclude that UAg is an iron-binding T. cruzi component eliminated in the urine of the infected host.