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Objective To investigate the distribution, drug resistance and molecular biological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) in our hospital, so as to provide reference for rational use of antibiotics and prevention and control of nosocomial CRKP infection. Methods Non-repetitive CRKP strains were collected from Jan. to Dec. 2019 in our hospital. VITEK 2 Compact automatic microbial analyzer and Kirby-Bauer test were used for bacterial identification and antimicrobial susceptibility analysis. WHONET 5.6 software was used to analyze CRKP detection rate, sample source and clinical department distribution. Hypermucoviscosity phenotype strains were screened by string test. Carbapenemase resistance genes, capsular serotype and virulence genes were detected by polymerase chain reaction (PCR). Results A total of 532 Klebsiella pneumoniae strains were detected, including 140 (26.3%) CRKP strains. The CRKP strains were mainly isolated from sputum and bronchoalveolar lavage fluid (66 strains, 47.1%), followed by urine (21 strains, 15.0%). The clinical departments of the isolates were mainly cardiovascular surgery intensive care unit (ICU) (47 strains, 33.6%), burn ICU (18 strains, 12.9%) and emergency department (18 strains, 12.9%). The antimicrobial susceptibility test showed that the CRKP strains were susceptible only to tigecycline, with resistance rates being over 50% to other common antibiotics. The resistance rates to the first to fourth generation cephalosporin antibiotics were above 85%, and the resistance rates to carbapenems were up to 100.0%. We also found that out of the 121 CRKP strains, 101 (83.5%) carried Klebsiella pneumoniae carbapenemase 2 (KPC-2) gene, seven (5.8%) with oxacillinase-48 (OXA-48) gene, and two (1.7%) with New Delhi metallo-β-lactmase 1 (NDM-1) gene; while one carried both KPC-2 and NDM-1 genes, and one carried both KPC-2 and OXA-48 genes; and nine carried no target drug-resistance genes. Fifteen (12.4%, 15/121) CRKP strains were positive for string test, with 13 being K64 capsular type and two being K47 capsular type; and 14 strains carried at least one virulence gene. Conclusion The clinical isolation rate of CRKP is high in our hospital, and the CRKP strains (mainly K64 capsular high virulence) are resistant to multiple antibiotics, suggesting that we should further strengthen the monitoring of drug resistance and rational use of antibiotics, so as to prevent the spread and prevalence of drug-resistant and highly virulent strains.
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Introduction: A new hypervirulent (hypermucoviscous)variant of Klebsiella pneumoniae has emerged. First describedin the Asian Pacific Rim, it now increasingly recognizedin Western countries. The dispute in the prevalence ofK. pneumoniae with these hypervirulent characteristicsbetween the infection and colonization condition are not wellunderstood. The objective of this study was to contrast theclinico-microbiological characteristics of K. pneumoniaeisolated from different samples.Material and methods: This retrospective study wasconducted at Department of Medicine, Osmania GeneralHospital, Hyderabad — a multi-speciality tertiary-careteaching hospital in Hyderabad, South India for the period ofSeptember 2016 to October 2017. 100 Patients whose sputumor urine tested positive for the presence of K. pneumoniaeisolates were randomly included in the study. Collectedpatient data included age, sex, underlying disease and useof immunosuppressant drugs. The samples were defined ascommunity isolates and hospital isolates depending uponcertain criteria. The cases were divided into infection andcolonization cases. All statistical analyses were performedusing JMP Pro version 12 software.Results: Of the 100 cases investigated, 55 and 45 cases showedthe presence of K. pneumoniae in the sputum and urine,respectively. Of the 100 K. pneumoniae isolates, 21(21%)showed capsular serotype K1 or K2, whereas 28(28%) showedhypermucoviscosity. The prevalence of virulence genes allS,magA, mrkD, rmpA, wabG, kfu-BC, and uge was 16.3%,13%, 81.9%, 18.6%, 90.3%, 38.5%, and 80.5%, respectively.Analysis of microbiological characteristics revealed thatonly rmpA was significantly more frequent in the infectioncases than in the colonization/asymptomatic cases in both thesputum and urine groups.Conclusion: The rmpA-positive K. pneumoniae isolates weredominant in the infection cases compared with those in thecolonization/asymptomatic cases, suggesting that rmpA mayplay a crucial role in the development of UTI and pneumonia.
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Objective To investigate the capsular polysaccharide (CPS) serotypes and molecular characteristics of carbapenem resistant hypermucoviscous Klebsiella pneumoniae (CR-HMKP) and study the possible mechanism of carbapenem resistance. Methods A retrospective study was conducted on 18 nonduplicate CR-HMKP strains which were collected from the First Affiliated Hospital of Nanchang University from 2012 to 2016. The clinical data were retrieved from medical records. The capsular serotypes, resistance genes and virulence factors were detected by polymerase chain reaction and DNA sequencing. Antimicrobial susceptibility testing was determined on VITEK 2 compact system. The CR-HMKP strains were characterized molecularly by using PCR, multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). Modified carbapenem inactivation method was used to screen carbapenemase-producing strains. Plasmid conjugation transfer experiments were carried out to study transmission of carbapenem resistance. Results Eighteen (2.7％) CR-HMKP isolates were identified, which belonged to 4 serotypes, including wzi128-K1 (n=1), wzi206-K57 (n=1), wzi2-K2 (n=2), and wzi64-K14.64 (n=14). PCR and sequencing analysis identified blaNDM-1 gene in 2 CR-HMKP strains, blaKPC-2 gene in 17 strains, qnrS1 gene in 18 strains, blaCTX-M-3 gene in 3 strains, blaCTX-M-14 gene in 18 strains, blaTEM-1 gene in 16 strains, blaSHV-12 gene in 17 strains, and rmtB in 5 strains. All the 18 CR-HMKP strains carried virulence-associated genes, including rmpA (88.9％, 16/18), magA (5.6％, 1/18), iroN (83.3％, 15/18), aerobactin (27.8％, 5/18), rmpA2 (66.7％, 12/18) and mrkD (100％, 18/18). Three sequence types (STs) were identified by MLST, including ST11 (15 strains), ST86 (2 strains), and ST412 (1 strain). PFGE resulted in three major PFGE clusters, of which cluster A corresponds to ST1 isolates, and cluster B corresponds to ST86 isolates, and cluster C corresponds to ST412 isolates. All the blaKPC-2- positive strains belonged to ST11. Plasmid conjugation was successful in 5 (27.8％) of the 18 CR-HMKP isolates. Conclusions wzi64-K14.64 is the predominant capsule serotype of the CR-HMKP strains in this hospital. KPC-2 gene conjugationmay contribute to the emergence of CR-HMKP isolates. In addition, CRHMKP strain may be the highly prevalent ST11, and highly virulent CPS serotypes harboring K1/K2.
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IntroductionKlebsiella spp is a well-known opportunistic pathogen associated with nosocomial infections such asurinary tract, septicaemia and pneumonia number of multi-drug resistant strains and infections causedby Klebsiella has progressively increased, causing treatment limitations.GoalIdentify of phenotype of Klebseilla isolates from ñlinical samplesMaterials and MethodsA total of 112 Klebsiella strains were isolated from clinical samples in State Central First Hospital and StateCentral Third Hospital from July 2015 through December 2015. The bacterial isolates were identifi edaccording to cultural characteristics, biochemical test and API20E. The serum resistance, capsule andhypermucoviscosity, cell surface protein (curly), a-hemolysin and ability to form biofi lm were sought byphenotypic assays. Antimicrobial susceptibility was tested by diffusion method.ResultA total of 112 Klebsiella samples were collected. The bacterial isolates were identifi ed according tocultural characteristics, biochemical test and API20E, the results revealed that 16.1 percent isolateswere identifi ed as K.oxytoca all of them 83.9 percent isolates were belong to K.pneumonia. Therewere observed for ampicillin (99 percent), nitrofurantoin (53.6 percent), cepalotin (50.6 percent) and51 percent of isolates were considered as a multiple drug resistant. Serum resistance properties ofK.pneumoniae was resistance 89.4 percent, intermediately susceptible 4.3 percent, sensitive 6.4percent and for K.oxytoca resistance 88.9 percent, intermediately susceptible 5.6 percent, sensitive 5.6percent. The hemolysin àalpha was detected in 32.2 percent, and gamma, beta in 66.96 percent, 0.9percent respectively. The capsule was observed in 46.5 percent and hypermucoviscosity in 27.7 percentof isolates. The cell surface protein (curly) and biofi lm were detected in 100 percent.Conclusion:Both K.pneumoniae and K.oxytoca isolates from clinical samples have similar virulent properties, andthe a-hemolysin and hypermucoviscosity positive isolates were more resistance to antibiotics.
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Pyogenic liver abscess caused by Klebsiella pneumoniae represents an ever increasing entity which has mainly been described as occurring in Asia, even though, on a smaller scale, cases are being more frequently described from the USA and Europe, 13% overall mortality being reached worldwide. Affected patients are severely sick, suffering from fever, sweating, having increased acute phase reactants and risk factors such as Diabetes Mellitus, alcoholism and the inherent characteristics of the bacteria causing the disease. Objective: in this work we used a Multilocus Sequencing Typing (MLST), a nucleotide sequence-based method in order to characterize the genetic relationships among bacterial isolates. Materials and methods: the report is focused on three cases involving patients suffering from pyogenic liver abscess caused by Klebsiella pneumoniae in two hospitals in Bogota, Colombia, where phenotyping and hypermucoviscosity studies were carried out, as well as the genotyping of cultured Klebsiella isolates. Results: it was found that the isolated microorganism in cases I and II corresponded to the same K. pneumoniae strain, having 100% sequence identity for the 5 genes being studied while the strain in Case III was genotypically different. Conclusion: it is important to carry out multidisciplinary studies allowing all pyogenic liver abscess cases reported in Colombia to be complied to ascertain the frequency of microorganisms causing this pathology in our country, as well as a genotyping study of different K. pneumoniae strains to compare them and confirm clonal and pathogenicity relationships through housekeeping gene analysis.
El absceso hepático piógeno causado por Klebsiella pneumoniae representa una entidad descrita con frecuencia en los países asiáticos y, en menor escala, también en Estados Unidos y Europa. En el ámbito mundial su mortalidad alcanza a un 13%. Los pacientes pueden presentar un compromiso severo, el cual cursa con fiebre, sudoración y aumento de reactantes de fase aguda, sobre todo en individuos con factores de riesgo como la diabetes mellitus y el alcoholismo, además de las características inherentes de la bacteria responsable de la infección. Objetivo: a continuación se presentan tres casos de pacientes con absceso hepático piógeno causado por Klebsiella pneumoniae en dos hospitales de Bogotá. Materiales y métodos: se realizó caracterización molecular de los aislados de Klebsiella mediante la técnica de Multilocus Secquence Typing (MLST), análisis fenotípicos y de hipermucoviscosidad. Resultado: se encontró que el microorganismo aislado en los casos I y II corresponde a la misma cepa de K. pneumoniae, que tiene 100% de identidad de secuencia de los 5 genes en estudio mientras que la cepa en Case III fue genotípicamente diferente. Conclusión: es importante llevar a cabo estudios multidisciplinarios que incluyan todos los casos de abscesos hepáticos piógenos reportados en Colombia con el objeto de determinar la frecuencia de los microorganismos causantes de esta patología en nuestro país, así como un estudio de genotipificación de diferentes cepas de K. pneumoniae para confirmar las relaciones clonales y de patogenicidad.
O abscesso hepático piogênico causado por Klebsiella pneumoniae representa uma entidade descrita com frequência nos países asiáticos e, em menor escala, também nos Estados Unidos e na Europa. No âmbito mundial sua mortalidade alcança um 13%. Os pacientes podem apresentar um compromisso severo, o qual cursa com febre, sudoração e aumento de reagentes de fase aguda, especialmente em indivíduos com fatores de risco como a diabetes mellitus e o alcoolismo, além das características inerentes da bactéria responsável da infecção. Objetivo: a continuação apresentamse três casos de pacientes com abscesso hepático piogênico causado por Klebsiella pneumoniae em dois hospitais de Bogotá; Materiais e métodos: realizou-se caracterização molecular dos isolados de Klebsiella mediante a técnica de Multilocus Secquence Typing (MLST), análises fenotípicas e de hipermucoviscosidade. Resultado: encontrou-se que o micro-organismo isolado nos casos I e II corresponde à mesma cepa de K. pneumoniae, que tem 100% de identidade de sequencia dos 5 genes em estudo enquanto a cepa no caso III foi genotipicamente diferente. Conclusão: é importante levar a cabo estudos multidisciplinares que incluam todos os casos de abscessos hepáticos piogênicos reportados na Colômbia com o objeto de determinar a frequência dos micro-organismos causadores desta patologia em nosso país, assim como um estudo de genotipificação de diferentes cepas de K. pneumoniae para confirmar as relações clonais e de patogenicidade.