Dissemination mechanism of blaKPC-2 among carbapenem-resistant Klebsiella pneumoniae strains / 中华微生物学和免疫学杂志

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is highly prevalent and poses a great health challenge due to the lack of effective treatments. Klebsiella pneumoniae carbapenemase-2 (KPC-2), encoded by blaKPC-2 gene, is one of the major contributors to carbapenem resistance in CRKP. In China and other Asian regions, Tn1721 and plasmid IncFⅡ are the main vectors for blaKPC-2 transfer between Kpn ST11 strains, which lack clustered regularly interspaced short palindromic repeats (CRISPR) and restriction-modification (R-M) systems. The structure of transposons has a significant impact on the transposition frequency of blaKPC-2, which may be related to the different transposition patterns of transposons. The prevalence advantage of blaKPC-2 in Kpn ST11 strains is highly associated with the immune deficiency in Kpn ST11. By acquiring a re-engineered CRISPR-Cas3 system via conjugation, the high-risk IncFⅡ plasmid can be successfully cleaved and ST11 CRKP can regain antibiotic sensitivity, which provides a promising approach for clinical treatment and prevention of CRKP.

Primer reporte de Enterobacterales dobles productores de carbapenemasas en hospitales de Paraguay. Año 2021

RESUMEN Las carbapenemasas se encuentran ampliamente distribuidas en nuestro país, tanto en bacilos gramnegativos fermentadores como no fermentadores. Durante 2021, se ha reportado incremento de cepas con estas enzimas. Con el objetivo de evaluar la doble producción de carbapenemasas en Enterobacterales y comunicar su circulación, fue puesta a punto una PCR convencional múltiple. Estudio retrospectivo en 128 aislamientos provenientes de 20 centros colaboradores de la Red Nacional de Vigilancia de la RAM (Capital, Central e interior del país), remitidos al LCSP entre febrero y setiembre de 2021, para confirmación y genotipificación de carbapenemasas. Se realizaron pruebas fenotípicas y colorimétricas con sustratos específicos, y pruebas genotípicas (PCR convencional múltiple) para la detección simultánea de varios genes de resistencia (bla NDM, bla KPC, bla OXA-48-like, bla IMP y bla VIM). De los 128 aislamientos estudiados, 107 correspondieron a Klebsiella pneumoniae, 14 a Enterobacter cloacae complex, entre otros; aislados en mayor frecuencia de muestras de orina (30%), respiratorias (30%), sangre y catéter (24%). Los genes de resistencia a los carbapenemes detectados fueron: bla NDM (77,3%), bla KPC (17,2%); siendo confirmada la doble producción de carbapenemasas en 7 aislamientos (5,5%) provenientes de 4 centros diferentes de la capital de país y uno de Central; 6 de ellas (K. pneumoniae) con bla NDM+bla KPC y 1 (E. cloacae complex) con bla NDM+bla OXA-48-like; confirmando circulación de Enterobacterales dobles productores de carbapenemasas en el país (KPC+NDM y OXA+NDM); hallazgos que obligan a proveer de capacidades de detección, de manera a que se puedan tomar medidas oportunas y eficaces de contención y control.

ABSTRACT Carbapenemases are widely distributed in our country, both in fermenting and non-fermenting gram-negative bacilli. During 2021, an increase in strains with these enzymes has been reported. In order to evaluate the double production of carbapenemases in Enterobacterales and communicate their circulation, a multiple conventional PCR was set up. Retrospective study carried out in 128 isolates from 20 collaborating centers of the National AMR Surveillance Network (Capital, Central and interior of the country), sent to the LCSP between February and September 2021, for confirmation and genotyping of carbapenemases. Phenotypic and colorimetric tests were performed with specific substrates, as well as genotypic tests (multiple conventional PCR) for the simultaneous detection of several resistance genes (blaNDM, blaKPC, blaOXA-48-like, blaIMP and blaVIM). Of the 128 isolates studied, 107 corresponded to Klebsiella pneumoniae, 14 to Enterobacter cloacae complex, among others; isolated in higher frequency from urine (30%), respiratory (30%), blood and catheter (24%) samples. The genes for resistance to carbapenems detected were: blaNDM (77.3%), blaKPC (17.2%); the double production of carbapenemases was confirmed in 7 isolates (5.5%) from 4 different centers in the capital of the country and one in Central; 6 of them (K. pneumoniae) with blaNDM + blaKPC and 1 (E. cloacae complex) with blaNDM + blaOXA-48-like; confirming circulation of double Enterobacterales producers of carbapenemases in the country (KPC + NDM and OXA + NDM); findings that require the provision of detection capabilities, so that timely and effective containment and control measures can be taken.

Molecular epidemiology of Klebsiella pneumoniae blaKPC gene in Lishui from 2010 to 2016 / 中华微生物学和免疫学杂志

Objective@#To investigate the distribution of blaKPC gene in Lishui and to analyze the molecular epidemiological characteristics of Klebsiella pneumoniae (K.pneumoniae) blaKPC gene.@*Methods@#From 2010 to 2016, all of the non-repetitive K. pneumoniae carbapenemase (KPC)-producing isolates in Lishui Municipal Central Hospital were collected. They were identified with VITEK 2 Compact system and typed by multilocus sequence typing (MLST). Plasmids were classified based on the DNA sequences of replication initiators. Transposons were detected by PCR. Locations of blaKPC gene were verified through complete sequencing of the plasmids by next-generation sequencing (NGS).@*Results@#A total of 125 strains were collected. K. pneumoniae strains accounted for 88.8% (111) and among them, 103 were ST11 type. IncF plasmids were detected in 48.6% of K. pneumoniae strains and most of them carried mutant Tn1721/Tn4401 chimera (48/54 isolates). Untypable plasmids were discovered in 50.5% of isolated strains and most of them were positive for the wild-type chimera (54/56 isolates). IncF-positive strains isolated during the period of 2011 and 2013 accounted for 94.4%, followed by a dramatic decrease. However, 76.8% of the strains harboring untypable plasmids were isolated from 2014 to 2016 and the number increased year by year.@*Conclusion@#K. pneumoniae of ST11 type was the main cause of blaKPC gene dissemination in Lishui area. Strains carrying the IncF plasmids integrated with the mutant Tn1721/Tn4401 chimera and the untypable plasmids with the wild-type chimera were prevalent before and after 2014, respectively.

KPC: Klebsiella pneumoniae carbapenemasa, principal carbapenemasa en enterobacterias / KPC: Klebsiella pneumoniae carbapenemase, main carbapenemase in Enterobacteriaceae

Resumen En la actualidad, la diseminación de enterobacterias productoras de carbapenemasas se considera un grave problema en clínica debido al fracaso en el tratamiento de las infecciones que ellas producen. Entre las carbapenemasas, la enzima KPC se ha diseminado mundialmente y ha sido identificada en las principales especies de enterobacterias relacionadas con infecciones asociadas a la atención en salud, con claro predominio de Klebsiella pneumoniae a nivel mundial. El gen blaKPC es transportado, principalmente, por el transposón Tn4401, detectado en diversas especies de enterobacterias con distintos secuencio-tipo (ST) y diferente origen geográfico. Adicionalmente, se han descrito nuevas plataformas genéticas que se distinguen del Tn4401 original debido a inserciones y deleciones de otros genes. Los plásmidos que albergan el gen blaKPC pueden ser del tipo conjugativo y no conjugativo movilizable, y además contener otros determinantes genéticos de resistencia. Las cepas productoras de KPC pueden presentar diversos niveles de resistencia a los carbapenémicos, debido a la participación de mecanismos adicionales como diferente grado de expresión de porinas y bombas de expulsión asociados con la producción de β-lactamasas de espectro extendido y/o AmpC. Sin embargo, las carbapenemasas, con KPC como la enzima más frecuente, otorgan grados de resistencia más elevados.

The dissemination of carbapenemase-producing Enterobacteriaceae is currently considered a serious clinical problem due to the failure in the treatment of infections produced by them. Among the carbapenemases, the enzyme KPC has spread worldwide and has been identified in the main enterobacterial species related with healthcareassociated infections, although Klebsiella pneumoniae is the predominant specie. The blaKPC gene is transported, mainly by the transposon Tn4401, detected in various enterobacterial species of different sequence types (ST) and geographical origin. In addition, new genetic platforms that are distinguished, from Tn4401 because of insertions or deletions of other genes have been described. Plasmids containing the blaKPC gene can be conjugative and mobilizable non-conjugative plasmids, and can carry other genetic determinants of resistance. The KPC-producing strains may have different levels of resistance to carbapenems, due to the involvement of additional mechanisms such as different expression levels of porins and efflux pumps associated with the production of extended spectrum β-lactamases and/or AmpC. However, the carbapenemases, with KPC as the most common enzyme, provide higher levels of resistance.

Susceptibility and prevalence of blaKPC gene in carbapenem-resistant Klebsiella pneumoniae / 中国感染与化疗杂志

Objective To examine the antimicrobial susceptibility and prevalence of blaKPC gene in carbapenem-resistant Klebsiella pneumoniae (CRKP) strains isolated in Huashan Hospital,Fudan University.Methods The CRKP strains isolated in Huashan Hospital from January to December of 2014 were included in this study.The MICs of antibiotics were determined using CLSI broth dilution method.The blaKPC gene was amplified by polymerase chain reaction (PCR).Results A total of 205 CRKP strains were isolated,mainly from respiratory tract (76.1％,156/205) and urine specimens (18.5％,38/205).Antimicrobial susceptibility test indicated that CRKP isolates had higher resistance rates (85％-100％) to the antimicrobial agents except colistin (1.5％),tigecycline (0.5％),trimethoprim-sulfamethoxazole (51.0％) and amikacin (74.9％).Most (87.8％,180/205) of the CRKP strains were positive for blaKPC gene.Conclusions CRKP are mostly isolated from patients with lower respiratory tract infection and/or urinary tract infection in Huashan Hospital.The strains were highly resistant to the antibacterial agents tested except colistin and tigecycline.Production of KPC-type carbapenemase is the common mechanism of carbapenem resistance in these K.pneumoniae isolates.

Detección de los genes de carbapenemasas blaKPC y blaNDM en aislamientos de Klebsiella pneumoniae del Hospital General San Juan de Dios de la ciudad de Guatemala

La resistencia a los antibióticos constituye uno de los problemas más relevantes de salud pública en todo el mundo. Las enterobacterias productoras de carbapenemasas representan la mayor amenaza. Las carbapenemasas son potentes enzimas que inactivan los antibióticos carbapenémicos y en general, a todos los antibióticos betalactámicos. Las consecuencias para el tratamiento de las infecciones causadas por estas bacterias son relevantes, ya que los carbapenemes son de las últimas opciones disponibles para bacterias multirresistentes. Esta investigación tuvo como objetivos determinar por medio de la reacción en cadena de la polimerasa (PCR) punto final, la presencia de los genes de carbapenemasas blaKPC (Klebsiella pneumoniae carbapenemasa) y blaNDM (New Delhi Metalobetalactamasa) en aislamientos de K. pneumoniae del Hospital General San Juan de Dios de la ciudad de Guatemala, caracterizar el tipo de muestra y definir el servicio del hospital donde se aislaron este tipo de bacterias. Se analizaron 54 aislamientos de K. pneumoniae resistentes a carbapenemes (imipenem y/o meropenem), 49 (91%) fueron portadoras del gen blaNDM. Estas bacterias se aislaron con más frecuencia en muestras de sangre (37%) y orina (14%). En esta investigación, el 53% de aislamientos se obtuvieron de pacientes de servicios de intensivos. Los resultados de este estudio indican que K. pneumoniae portadora del gen blaNDM se ha diseminado dentro del Hospital General San Juan de Dios, desde el primer caso reportado hace cinco años, poniendo en riesgo de muerte a los pacientes, especialmente a los hospitalizados en los servicios de intensivos.

Resistance to antibiotics is one of the most important public health problems worldwide. Enterobacteriaceae producing carbapenemases pose the greatest threat. The carbapenemases are powerful enzymes that inactivate carbapenem antibiotics and generally all beta-lactam antibiotics. The consequences for the treatment of infections caused by these bacteria are important because carbapenems are the latest options available for multidrug-resistant bacteria. This research aimed to determine through endpoint polymerase chain reaction (PCR), the presence of the carbapenemases encoding genes blaKPC (Klebsiella pneumoniae carbapenemase) and blaNDM (New Delhi metallolactamase) in K. pneumoniae isolates from San Juan de Dios General Hospital located in Guatemala City; and to characterize the sample type and define the service of the hospital where such bacteria were isolated 54 K. pneumoniae isolates resistant to carbapenems (imipenem and / or meropenem), were analyzed. From these, 49 (91 %) were detected as blaNDM gene carriers. These bacteria were isolated more frequently in blood samples (37%) and urine (14%). In this research, 53% of isolates were obtained from patients hospitalized in intensive care units. This study demonstrates that K. pneumoniae carrying the blaNDM gene has spread within San Juan de Dios General Hospital, since the first reported case five years ago, risking the life of patients, especially of those hospitalized in intensive care services.

A structural, epidemiological & genetic overview of Klebsiella pneumoniae carbapenemases (KPCs).

Klebsiella pneumoniae carbapenemases (KPCs) are plasmid encoded carbapenem hydrolyzing enzymes which have the potential to spread widely through gene transfer. The instability of upstream region of blaKPC accelerates emergence of different isoforms. Routine antibiotic susceptibility testing failed to detect KPC producers and some commercial kits have been launched for early identification of KPC producers. Notable among the drugs under development against KPC are mostly derivatives of polymixin; β-lactamase inhibitor NXL104 with combination of oxyimino cephalosporin as well as with ceftazidime; a novel tricyclic carbapenem, LK-157, potentially useful against class A and class C enzymes; BLI-489-a bicyclic penem derivative; PTK-0796, a tetracycline derivative and ACHN-490. Combination therapy might be preferable to control KPC infections in immediate future. Clinicians are likely to opt for unconventional combinations of antibiotics to treat KPC infections because of unavailability of alternative agents. The KPCs have become endemic in many countries but there is no optimal treatment recommendation available for bacteria expressing KPCs. Reports of outbreaks involving KPCs have focused mainly on laboratory identification, empirical treatment outcomes and molecular epidemiology. This review includes information on the emergence of KPC variants, limitations of phenotyping methods, available molecular methods for identification of the KPC variants and treatment options highlighting the drugs under development.

Analysis of polymyxin susceptibility in Enterobacteriaceae / 中国感染与化疗杂志

Objective To investigate the distribution and antimicrobial susceptibility of clinical strains ofEnterobacteriaceae isolated from Huashan Hospital in 2014.MethodsEnterobacteriaceae were isolated from January to August 2014. Antimicrobial susceptibility testing was performed by agar dilution method. TheblaKPC gene was screened by PCR and DNA sequencing. Results were analyzed by WHONET 5.6 software.Results A total of 719 strains ofEnterobacteriaceae were collected, of whichKlebsiella spp., andE .coli accounted for 43.8% (315/719) and 30.4% (219/719), respectively. Resistance rates ofKlebsiella spp.,E. coli, andCitrobacter spp., to polymyxin B and polymyxin E were low (<3%). The percentage of theEnterobacter strains resistant to polymyxin B and polymyxin E was 10.9% and 11.1%, respectively. About 47.5% and 44.7% of theSerratia strains were resistant to polymyxin B and polymyxin E, respectively. More than 90% of theMorganella andProteus isolates were resistant to polymyxin B or polymyxin E. The carbapenem-resistantEnterobacteriaceae strains were mainly identiifed inKlebsiella isolates, more than 40% of which were resistant to meropenem and ertapenem, but only 2.9% and 2.6% were resistant to polymyxin B and polymyxin E, respectively. Ertapenem resistance was identified in 27.8% of theCitrobacter isolates and 17.9% of theSerratia isolates. Less than 10% of the otherEnterobacteriaceae strains were resistant to carbapenem. Overall, 20.7% (149/719) of the isolates wereblaKPC positive, mainly inK. pneumoniae (129/315, 41.0%). Seven strains ofSerratia marcescens and 2 strains ofK. Pneumoniae were resistant to both carbapenems and polymyxin.Conclusions The clinical isolates ofKlebsiella, E. coli, Enterobacter andCitrobacter in 2014 were still highly susceptible to polymyxin antibiotics.

occurrence of blaNDM-1 & absence of blaKPC genes encoding carbapenem resistance in uropathogens from a tertiary care centre from north India.

Background & objectives: Carbapenem resistance mediated by carbapenemases is increasingly being reported worldwide. This study was conducted to know the occurrence of important carbapenem resistance encoding genes in gram-negative bacilli (GNB) causing complicated urinary tract infection (CUTI), and to look at the genetic diversity of these isolates. Methods: The study was carried out on 166 consecutive carbapenem resistant uropathogens (CRU) isolated from cases with CUTI during 2008 and 2012. Carbapenemase production was characterized phenotypically and polymerase chain reaction was used to detect blaVIM, blaIMP, blaKPC, and blaNDM-1. BOX- PCR was done on 80 randomly selected isolates for molecular typing. Results: The blaVIM gene was present in 34 (43.6%), blaIMP in five (6.4%) and none of the isolates from 2008 had blaNDM-1 or blaKPC genes. Among the isolates from 2012, blaNDM-1 gene was present in 47 (53.4%), blaVIM in 19 (24.4%), blaIMP in one (1.1%) and none had blaKPC. There were nine isolates during the two years which had multiple genes encoding carbapenemases; while 66 did not have any of the genes tested. Of the 80 isolates subjected to BOX-PCR, 58 could be used for analysis and showed, presence of multiple clusters of carbapenem resistant isolates and absence of a single dominant clone. Interpretation & conclusions: The blaNDM-1 gene was absent in our isolates obtained during 2008 but was present amongst Enterobacteriaceae isolated in 2012. The blaKPC gene was also not found. Nine isolates obtained during the two years had multiple genes encoding carbapenemases confirming the previous reports of emergence of GNB containing genes encoding multiple carbapenemases. Typing using BOX-PCR indicated that this emergence was not because of clonal expansion of a single strain, and multiple strains were circulating at a single point of time.

Isolation of carbapenemase KPC-2 producing Klebsiella pneumoniae and Pseudo-monas aeruginosa strains and resistance research / 军事医学

Objective To investigate the carbapenem-resistant mechanism of one strain of Klebsiella pneumoniae( KPN) and one strain of Pseudomonas aeruginosa( PAE) .Methods The identity of the isolates was confirmed by using MALDI-TOF mass spectrometry, 16S rDNA and special gene amplification .The minimum inhibitory concentrations (MICs) of the antimicrobial agents were determined by VITEK 2 Compact System .CarbaNP Antimicrobial susceptibility testing , plasmid extraction, electroporation experiment , PCR amplification, and cloning and sequencing were carried out to analyze the en-coding gene of β-lactamases.Results The types of β-lactamases of the KPN were blaKPC-2 and blaSHV, confirmed by se-quencing of the PCR products , and that of the PAE were blaKPC-2 .Only blaKPC-2 was displayed in both transformants .All of the results of CarbaNP were type A .Conclusion Both strains of KPN and PAE resisting to carbapenem produce a plasmid-mediated carbapenemase blaKPC-2 , which belongs to Bush group 2f, class A β-lactamase.The extended-spectrum β-lacta-mases gene encoding blaSHV of the KPN might be located in the chromosome or not in the plasmid carrying with blaKPC-2 .

Infecções hospitalares por enterobactérias produtoras de Kpc em um hospital terciário do sul do Brasil / Nosocomial infections by KPC-producing enterobacteria in a tertiary hospital in Southern Brazil

Introdução: A prevalência do gene blaKpc entre as bactérias gram-negativas continua a aumentar globalmente e está se disseminando em nosso hospital desde 2009. O tratamento de infecções causadas por esses patógenos constitui um desafio para os médicos. Métodos: Estudo retrospectivo descritivo. Descrevemos as características clínicas e epidemiológicas dos pacientes que apresentam, em exames de espécimes clínicos, enterobactérias produtoras do gene blaKpc (KPC) entre 2009 e 2012 em um hospital terciário em Porto Alegre, Brasil. Resultados: Setenta e sete pacientes foram incluídos nesse estudo. Destes, 47 (61%) desenvolveram quadro de infecção por KPC. A taxa de mortalidade associada à infecção por KPC foi de 18% entre todos 77 pacientes. Conclusão: A infecção por KPC está associada à alta mortalidade. A implementação de medidas de controle de infecção e política de uso de antimicrobianos são importantes para a redução da disseminação de KPC

Introduction: The prevalence of the gene blaKpc among gram-negative bacteria continues to increase globally and is spreading in our hospital since 2009. The treatment of infections caused by these pathogens is a major challenge for physicians. Methods: A retrospective descriptive study. We describe the clinical and epidemiological characteristics of patients who presented gene blaKpc-producing (KPC) enterobacteria in clinical specimens tests between 2009 and 2012 in a tertiary hospital in Porto Alegre, Brazil. Results: Seventy-seven patients were included in this study. Of these, 47 (61%) developed a picture of KPC infection. The mortality rate associated with KPC infection was 18% among all 77 patients. Conclusion: KPC infection is associated with high mortality. The implementation of infection control measures and antimicrobial use policy are important for reducing the spread of KPC

Analysis of carbapenemase genotypes of carbapenem-resistant Proteus mirabilis strains clinically isolated from 2009 to 2012 / 中华微生物学和免疫学杂志

Objective To investigate the clinical distribution and the drug resistance of carbapenemresistant Proteus mirabilis strains isolated from 2009 to 2012 ; and to study carbapenemase genotypes of the isolates.Methods A total of 15 non-repetitive carbapenem-resistant Proteus mirabilis strains were selected from 422 Proteus mirabilis strains isolated from Ningbo First Hospital during January 2009 to December 2012.The minimal inhibitory concentrations (MIC) of 6 antibacterial agents,including imipenem (IPM),meropenem (MEM),ertapenem (ETP),ciprofloxacin (CIP),amikacin (AK) and minocycline (MIN),against 15 isolates were determined by E-test.The modified Hodge test (MHT) was used to detect the carbapenemase production in isolates.The PCR assay was performed to detect drug resistance genes of blaKPC,blaNDM-1,blaGES,blaSME,blaIMI-1/NmcA and blaSHV-38.Plasmids were extracted from the blaKPC-positive strains and then transformed into Escherichia coli J53 strains by electroporation.The transformed and untransformed Escherichia coli J53 strains were tested for MIC values and blaKPC gene by E-test and PCR respectively.Results The resistance rates of the 15 carbapenem-resistant Proteus mirabilis strains to IPM,MEM,ETP,CIP,AK and MIN were 100％,100％,100％,86.7％ (13/15),33.3％ (5/15) and 80％ (12/15),respectively.7 out of 15 strains were Hodge test positive,and 11 strains were blaKPC-2 positive.Results of PCR amplification showed that the transformed Escherichia coli J53 strains,whose MIC values to IPM,MEM,and ETP were increased by 2 to 64 times,were blaKPC-2 gene positive.Conclusion The carbapenem-resistant Proteus mirabilis strains in this study were resistant to many commonly used antibiotics,however,the resistance rates to AK were relatively low.The dominant carbapenemase genotype was blaKPC-2 carried by the plasmid.Attention should be paid to its easily transmissible feature among the strains in clinic.

Multidrug resistance genes, including blaKPC and blaCTX-M-2, among Klebsiella pneumoniae isolated in Recife, Brazil / Genes de multirresistência, incluindo blaKPC e blaCTX-M-2, em Klebsiella pneumoniae isoladas em Recife, Brasil

INTRODUCTION: The prevalence of cephalosporins and carbapenem-resistant Klebsiella pneumoniae strains is rising in Brazil, with potential serious consequences in terms of patients' outcomes and general care. METHODS: This study characterized 24 clinical isolates of K. pneumoniae from two hospitals in Recife, Brazil, through the antimicrobial susceptibility profile, analyses of β-lactamase genes (blaTEM, blaSHV,blaCTX-MblaKPC, blaVIM, blaIMP, and blaSPM), plasmidial profile and ERIC-PCR (Enterobacterial repetitive intergenic consensus-polymerase chain reaction). RESULTS: ERIC-PCR and plasmidial analysis grouped the isolates in 17 and 19 patterns, respectively. Six isolates from one hospital presented the same pattern by ERIC-PCR, indicating clonal dissemination. All isolates presented blaSHV, 62.5% presented blaCTX-M-2, 29% blaTEM, and 41.7% blaKPC. Metallo-β-lactamase genes blaand blawere not detected. Eleven isolates were identified carrying at least 3 β-lactamase studied genes, and 2 isolates carried blaSHVblaTEM, blaCTX-M-2 and blaKPC simultaneously. CONCLUSIONS: The accumulation of resistance genes in some strains, observed in this study, imposes limitations in the therapeutic options available for the treatment of infections caused by K. pneumoniae in Recife, Brazil. These results should alert the Brazilian medical authorities to establish rigorous methods for more efficiently control the dissemination of antimicrobial resistance genes in the hospital environment.

INTRODUÇÃO: A prevalência de cepas de Klebsiella pneumoniae resistentes a cefalosporinas e carbapenêmicos está aumentando no Brasil, com sérias consequências em termos de desfechos dos pacientes e cuidados gerais. MÉTODOS: Este estudo caracterizou 24 isolados clínicos de K. pneumoniae provenientes de dois hospitais de Recife, Brasil, através do perfil de susceptibilidade a antimicrobianos, análise de genes de β-lactamase (blaTEM,blaSHV,blaCTX-MblaKPC,blaVIM, blaIMP,and blaSPM), perfil plasmidial e ERIC-PCR (Enterobacterial repetitive intergenic consensus-polymerase chain reaction). RESULTADOS: A análise da ERIC-PCR e do perfil plasmidial agrupou os isolados em 17 e 19 perfis, respectivamente. Seis isolados de um hospital apresentaram o mesmo padrão de ERIC-PCR, indicando disseminação clonal. Todos os isolados apresentaram blaSHV, 62,5% apresentaram blaCTX-M-2, 29% blaTEM e 41,7% blaKPC. Genes de metalo-β-lactamase blaVIM, blaIMP e blaSPM não foram detectados. Onze isolados foram identificados carreando, pelo menos, três dos genes de β-lactamase estudados, dentre estes, dois isolados continham blaSHV,blaTEM, blaCTX-M-2 e blaKPC simultaneamente. CONCLUSÕES: O acúmulo de genes de resistência em algumas cepas, observado nesse estudo, impõem limitações nas opções terapêuticas disponíveis para o tratamento de infecções causadas por K. pneumoniae em Recife, Brasil. Estes resultados devem alertar as autoridades médicas brasileiras para estabelecer rigorosos métodos para controlar eficientemente a disseminação de genes de resistência a antimicrobianos no ambiente hospitalar.