RESUMO
There is an enormous global public health burden due to antimicrobial-resistant (AMR) Klebsiella pneumoniae high-risk clones. K. pneumoniae ST307 and ST147 are recent additions to the family of successful clones in the species. Both clones likely emerged in Europe during the early to mid-1990s and, in a relatively short time, became prominent global pathogens, spreading to all continents (with the exception of Antarctica). ST307 and ST147 consist of multiple clades/clusters and are associated with various carbapenemases (i.e., KPCs, NDMs, OXA-48-like, and VIMs). ST307 is endemic in Italy, Colombia, the United States (Texas), and South Africa, while ST147 is endemic in India, Italy, Greece, and certain North African countries. Both clones have been introduced into regions of nonendemicity, leading to worldwide nosocomial outbreaks. Genomic studies showed ST307 and ST147 contain identical gyrA and parC mutations and likely obtained plasmids with blaCTX-M-15 during the early to mid-2000s, which aided in their global distribution. ST307 and ST147 then acquired plasmids with various carbapenemases during the late 2000s, establishing themselves as important AMR pathogens in certain regions. Both clones are likely underreported due to restricted detection methodologies. ST307 and ST147 have the ability to become major threats to public health due to their worldwide distribution, ability to cause serious infections, and association with AMR, including panresistance. The medical community at large, especially those concerned with antimicrobial resistance, should be aware of the looming threat posed by emerging AMR high-risk clones such as K. pneumoniae ST307 and ST147.
Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , África do Norte , Antibacterianos/farmacologia , Células Clonais , Colômbia , Farmacorresistência Bacteriana Múltipla/genética , Europa (Continente) , Grécia , Humanos , Índia , Itália , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , África do Sul , Texas , beta-Lactamases/genéticaRESUMO
We report a fatal bacteremia caused by Klebsiella pneumoniae in a 60-70-year-old patient from Brazil. The genomic analysis of three isolates (from blood culture, nasal and anal swabs) showed that the bacteremia was caused by a KPC-2 producing extensively drug-resistant K64-ST11 hypermucousviscous K. pneumoniae (hmKP) harboring several virulence and antimicrobial resistance genes. Although the isolates did not present virulence markers associated with hypervirulent K. pneumoniae (hvKP), they showed invasion and toxicity to epithelial Hep-2 cells; resistance to cell microbicidal mechanisms; and blood and human serum survival, evidencing their pathogenic potential. This study highlights the risk of infection caused by hmKp strains not characterized as hvKP as well as the clinical implications and difficulty of treatment, especially in elderly or immunocompromised patients.
RESUMO
International data on the molecular epidemiology of Enterobacteriaceae with IMP carbapenemases are lacking. We performed short-read (Illumina) whole-genome sequencing on a global collection of 38 IMP-producing clinical Enterobacteriaceae (2008 to 2014). IMP-producing Enterobacteriaceae (7 varieties within 11 class 1 integrons) were mainly present in the South Pacific and Asia. Specific blaIMP-containing integrons (In809 with blaIMP-4, In722 with blaIMP-6, and In687 with blaIMP-14) were circulating among different bacteria in countries such as Australia, Japan, and Thailand. In1312 with blaIMP-1 was present in Klebsiella pneumoniae from Japan and Citrobacter freundii from Brazil. Klebsiella pneumoniae (n = 22) was the most common species; clonal complex 14 (CC14) from Philippines and Japan was the most common clone and contained In1310 with blaIMP-26 and In1321 with blaIMP-6 The Enterobacter cloacae complex (n = 9) consisted of Enterobacter hormaechei and E. cloacae cluster III. CC78 (from Taiwan) containing In73 with blaIMP-8 was the most common clone among the E. cloacae complex. This study highlights the importance of surveillance programs using the latest molecular techniques for providing insight into the characteristics and global distribution of Enterobacteriaceae with blaIMP genes.
Assuntos
Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Inosina Monofosfato/metabolismo , beta-Lactamases/metabolismo , Brasil , Citrobacter freundii/enzimologia , Citrobacter freundii/genética , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , beta-Lactamases/genéticaRESUMO
The present study reports the dissemination of multidrug-resistant (MDR) OXA-23-producing Acinetobacter baumannii clones throughout hospitals in Rio de Janeiro, Brazil. A total of 110 imipenem-resistant A. baumannii isolates were obtained from January 2006 to September 2007 in eight hospitals. The modified Hodge test was performed to screen for carbapenemase production. Polymerase chain reaction (PCR) and DNA sequencing were performed for the detection of bla(IMP), bla(VIM), bla(OXA-23-like), bla(OXA-24-like), bla(OXA-58) and the class 1 integron. Isolates were typed by pulsed-field gel electrophoresis (PFGE) following digestion with ApaI. All the isolates were MDR and 96 (87.3%) produced the carbapenemase OXA-23. No isolates produced OXA-24, OXA-58 or the metallo-beta-lactamases IMP and VIM. The class 1 integron was absent in all isolates. The A. baumannii isolates were separated into five genotypes, with the highest prevalence of genotype A (71.8%) followed by genotype B (22.7%). Genotype A was present in seven hospitals, whilst genotype B had spread in five hospitals. The OXA-23-producing isolates belonged to all genotypes. The presence of MDR OXA-23-producing A. baumannii in different hospitals in Rio de Janeiro emphasises the need to control the use of carbapenems and to prevent the spread of these organisms in Rio de Janeiro.
Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/enzimologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , beta-Lactamases/biossíntese , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Genótipo , Hospitais , Humanos , Integrons , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , beta-Lactamases/genéticaRESUMO
OBJECTIVES: The aim of this study was to characterize the KPC-type carbapenem-hydrolysing beta-lactamase, extended-spectrum beta-lactamases (ESBLs) and class 1 integrons among nosocomial Klebsiella pneumoniae isolated in Rio de Janeiro, Brazil. METHODS: MICs were determined and isolates were screened for ESBLs, metallo-beta-lactamases (MBLs) and class A carbapenemase-producing phenotypes. The main beta-lactamases resistance genes (bla(TEM), bla(SHV), bla(CTX-M), bla(KPC), bla(IMP) and bla(VIM)) and class 1 integrons were detected by PCR followed by DNA sequencing. The genetic relatedness of isolates was determined by PFGE. RESULTS: All K. pneumoniae isolates were positive for ESBL and class A carbapenemase production and negative for MBL production. All isolates were resistant to all beta-lactam antibiotics, ciprofloxacin and gentamicin, being susceptible only to tigecycline and polymyxin B. The bla(KPC-2), bla(CTX-M-1), bla(CTX-M-2), bla(CTX-M-8) and bla(SHV-11) genes were detected. PFGE analysis revealed two clonal types among KPC-producing isolates, both identified in the same hospital. CONCLUSIONS: Our findings should alert medical authorities to implement stringent methods for the detection and spread control of emerging KPC-2 carbapenemases in the hospital setting in Brazil.
Assuntos
Antibacterianos/antagonistas & inibidores , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/genética , beta-Lactamases/metabolismo , beta-Lactamas/antagonistas & inibidores , Antibacterianos/metabolismo , Técnicas de Tipagem Bacteriana , Brasil , Infecção Hospitalar/microbiologia , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Integrons , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Resistência beta-Lactâmica , beta-Lactamas/metabolismoRESUMO
OBJECTIVES: To describe a novel trimethoprim resistance gene, designated dfrA25, which was detected as a gene cassette within a class 1 integron in Salmonella Agona. METHODS: The gene was cloned into Escherichia coli MT102 and resistance to 10 different antimicrobial drugs was measured. A phylogenetic tree was constructed based on representative trimethoprim-resistance-mediating DfrA proteins retrieved from GenBank. Filter-mating experiments and Southern blots of plasmid preparations were performed with the donor and selected transconjugants. RESULTS AND CONCLUSIONS: dfrA25 encodes a dihydrofolate reductase of 157 amino acids with closest identity (85%) to dfrA5 dihydrofolate reductase. dfrA25 was located on a transferable plasmid (approximately 150 kb) that also harboured the tetracycline resistance gene tet(A).
Assuntos
Infecções por Salmonella/microbiologia , Salmonella/genética , Tetra-Hidrofolato Desidrogenase/genética , Resistência a Trimetoprima/genética , Sequência de Bases , Brasil , Humanos , Dados de Sequência Molecular , Filogenia , Salmonella/enzimologia , Salmonella/isolamento & purificação , Infecções por Salmonella/urina , Urina/microbiologiaRESUMO
A total of 296 Shigella spp. were received from State Public Health Laboratories, during the period from 1999 to 2004, by National Reference Laboratory for Cholera and Enteric Diseases (NRLCED)--IOC/Fiocruz, Rio de Janeiro, Brazil. The frequency of Shigella spp. was: S. flexneri (52.7%), S. sonnei (44.2%), S. boydii (2.3%), and S. dysenteriae (0.6%). The most frequent S. flexneri serovars were 2a and 1b. The highest incidence rates of Shigella isolation were observed in the Southeast (39%) and Northeast (34%) regions and the lowest rate in the South (3%) of Brazil. Strains were further analyzed for antimicrobial susceptibility by disk diffusion method as part of a surveillance program on antimicrobial resistance. The highest rates of antimicrobial resistance were to trimethoprim-sulfamethozaxole (90%), tetracycline (88%), ampicillin (56%), and chloramphenicol (35%). The patterns of antimicrobial resistance among Shigella isolates pose a major difficulty in the determination of an appropriate drug for shigellosis treatment. Continuous monitoring of antimicrobial susceptibilities of Shigella spp. through a surveillance system is thus essential for effective therapy and control measures against shigellosis.
Assuntos
Antibacterianos/farmacologia , Shigella/efeitos dos fármacos , Brasil , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Prevalência , Sorotipagem , Shigella/classificaçãoRESUMO
OBJECTIVES: To determine the occurrence of antimicrobial resistance genes and role of integrons among 135 antimicrobial-resistant Salmonella enterica from Brazil. METHODS: The presence of antimicrobial resistance genes, class 1 and 2 integrons and gene cassettes was analysed by PCR and sequencing. The genetic location of class 1 integrons was determined in 25 isolates by hybridization and plasmid transfer experiments. RESULTS: Fifty-five of the isolates were positive for class 1 integrons. Integron-positive isolates represented 17 different serovars and were mainly from human (n=28) and animal (n=13) sources. The gene cassette arrangements could be determined in 51 of the positive isolates, which harboured one [dfrA22, aadA1 or orf3 (putative trimethoprim resistance)], two [aadA1-dfrA1, aac(6')-Ib-orf1 (unknown function) or aacA4-aadA1], three [dfrA15b-cmlA4-aadA2, orf2 (unknown function)-dfrA5-orfD] or four [orf4-aacA4-blaOXA-30 (interrupted by an IS1 element)-aadA1] cassettes in their variable region. Only one isolate harboured a class 2 integron with the gene cassette array dfrA1-sat-aadA1. Several integron unrelated resistance genes were also detected in the isolates. Sulphonamide resistance was primarily mediated by sul2 and sul3, tetracycline resistance by tet(B) and tet(A), chloramphenicol resistance by catA1, streptomycin resistance by strA and ampicillin resistance by blaTEM. blaCTX and blaCMY-2 were found in cephalosporin-resistant isolates. Mating and hybridization experiments demonstrated that a high-molecular-weight plasmid mediated the gene transfer of integrons and additional resistance determinants. CONCLUSIONS: The present study revealed that integron-mediated resistance genes contributed to the multiresistance phenotype observed in the isolates, but most resistance genes were located outside the integron structure, as independent genes. However, they might be located on the same conjugative plasmid.
Assuntos
Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana Múltipla/genética , Integrons/genética , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , Antibacterianos/farmacologia , Brasil , Conjugação Genética , DNA Bacteriano/genética , Transferência Genética Horizontal , Genes Bacterianos , Humanos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Plasmídeos , Reação em Cadeia da Polimerase , Salmonella enterica/isolamento & purificação , Análise de Sequência de DNARESUMO
A total of 296 Shigella spp. were received from State Public Health Laboratories, during the period from 1999 to 2004, by National Reference Laboratory for Cholera and Enteric Diseases (NRLCED) - IOC/Fiocruz, Rio de Janeiro, Brazil. The frequency of Shigella spp. was: S. flexneri (52.7 percent), S. sonnei (44.2 percent), S. boydii (2.3 percent), and S. dysenteriae (0.6 percent). The most frequent S. flexneri serovars were 2a and 1b. The highest incidence rates of Shigella isolation were observed in the Southeast (39 percent) and Northeast (34 percent) regions and the lowest rate in the South (3 percent) of Brazil. Strains were further analyzed for antimicrobial susceptibility by disk diffusion method as part of a surveillance program on antimicrobial resistance. The highest rates of antimicrobial resistance were to trimethoprim-sulfamethozaxole (90 percent), tetracycline (88 percent), ampicillin (56 percent), and chloramphenicol (35 percent). The patterns of antimicrobial resistance among Shigella isolates pose a major difficulty in the determination of an appropriate drug for shigellosis treatment. Continuous monitoring of antimicrobial susceptibilities of Shigella spp. through a surveillance system is thus essential for effective therapy and control measures against shigellosis.