Increased Detection of Carbapenemase-Producing Enterobacterales Bacteria in Latin America and the Caribbean during the COVID-19 Pandemic.

During 2020-2021, countries in Latin America and the Caribbean reported clinical emergence of carbapenemase-producing Enterobacterales that had not been previously characterized locally, increased prevalence of carbapenemases that had previously been detected, and co-production of multiple carbapenemases in some isolates. These increases were likely fueled by changes related to the COVID-19 pandemic, including empirical antibiotic use for potential COVID-19-related bacterial infections and healthcare limitations resulting from the rapid rise in COVID-19 cases. Strengthening antimicrobial resistance surveillance, epidemiologic research, and infection prevention and control programs and antimicrobial stewardship in clinical settings can help prevent emergence and transmission of carbapenemase-producing Enterobacterales.

Complexity of Genomic Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Isolates in Colombia Urges the Reinforcement of Whole Genome Sequencing-Based Surveillance Programs.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging public health problem. This study explores the specifics of CRKP epidemiology in Colombia based on whole genome sequencing (WGS) of the National Reference Laboratory at Instituto Nacional de Salud (INS)'s 2013-2017 sample collection. METHODS: A total of 425 CRKP isolates from 21 departments were analyzed by HiSeq-X10®Illumina high-throughput sequencing. Bioinformatic analysis was performed, primarily using the pipelines developed collaboratively by the National Institute for Health Research Global Health Research Unit (GHRU) on Genomic Surveillance of Antimicrobial Resistance (AMR), and AGROSAVIA. RESULTS: Of the 425 CRKP isolates, 91.5% were carbapenemase-producing strains. The data support a recent expansion and the endemicity of CRKP in Colombia with the circulation of 7 high-risk clones, the most frequent being CG258 (48.39% of isolates). We identified genes encoding carbapenemases blaKPC-3, blaKPC-2, blaNDM-1, blaNDM-9, blaVIM-2, blaVIM-4, and blaVIM-24, and various mobile genetic elements (MGE). The virulence of CRKP isolates was low, but colibactin (clb3) was present in 25.2% of isolates, and a hypervirulent CRKP clone (CG380) was reported for the first time in Colombia. ST258, ST512, and ST4851 were characterized by low levels of diversity in the core genome (ANI > 99.9%). CONCLUSIONS: The study outlines complex CRKP epidemiology in Colombia. CG258 expanded clonally and carries specific carbapenemases in specific MGEs, while the other high-risk clones (CG147, CG307, and CG152) present a more diverse complement of carbapenemases. The specifics of the Colombian situation stress the importance of WGS-based surveillance to monitor evolutionary trends of sequence types (STs), MGE, and resistance and virulence genes.

Genome-based characterization of two Colombian clinical Providencia rettgeri isolates co-harboring NDM-1, VIM-2, and other ß-lactamases.

BACKGROUND: Providencia rettgeri is a nosocomial pathogen associated with urinary tract infections and related to Healthcare-Associated Infection (HAI). In recent years isolates producing New Delhi Metallo-ß-lactamase (NDM) and other ß-lactamases have been reported that reduce the efficiency of clinical antimicrobial treatments. In this study, we analyzed antibiotic resistance, the presence of resistance genes and the clonal relationship of two P. rettgeri isolates obtained from male patients admitted to the same hospital in Bogotá - Colombia, 2015. RESULTS: Antibiotic susceptibility profile evaluated by the Kirby-Bauer method revealed that both isolates were resistant to third-generation carbapenems and cephalosporins. Whole-genome sequencing (Illumina HiSeq) followed by SPAdes assembling, Prokka annotation in combination with an in-house Python program and resistance gene detection by ResFinder identified the same six ß-lactamase genes in both isolates: blaNDM-1, blaVIM-2, blaCTX-M-15, blaOXA-10, blaCMY-2 and blaTEM-1. Additionally, various resistance genes associated with antibiotic target alteration (arnA, PmrE, PmrF, LpxA, LpxC, gyrB, folP, murA, rpoB, rpsL, tet34) were found and four efflux pumps (RosAB, EmrD, mdtH and cmlA). The additional resistance to gentamicin in one of the two isolates could be explained by a detected SNP in CpxA (Cys191Arg) which is involved in the stress response of the bacterial envelope. Genome BLAST comparison using CGView, the ANI value (99.99%) and the pangenome (using Roary) phylogenetic tree (same clade, small distance) showed high similarity between the isolates. The rMLST analysis indicated that both isolates were typed as rST-61,696, same as the RB151 isolate previously isolated in Bucaramanga, Colombia, 2013, and the FDAARGOS_330 isolate isolated in the USA, 2015. CONCLUSIONS: We report the coexistence of the carbapenemase genes blaNDM-1, and blaVIM-2, together with the ß-lactamase genes blaCTX-M-15, blaOXA-10, blaCMY-2 and blaTEM-1, in P. rettgeri isolates from two patients in Colombia. Whole-genome sequence analysis indicated a circulation of P. rettgeri rST-61,696 strains in America that needs to be investigated further.

[National surveillance of clinical isolates of Enterococcus faecalis resistant to linezolid carrying the optrA gene in Colombia, 2014-2019]. / Vigilancia nacional de aislamientos clínicos de Enterococcus faecalis resistentes al linezolid portadores del gen optrA en Colombia, 2014-2019.

OBJECTIVE: To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. METHODS: Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. RESULTS: The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256µg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. CONCLUSION: OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.

Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring mcr-1 in Colombia, 2002 to 2016.

Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 × 10-5 to 2.07 × 10-1 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids.

[Emergence of resistance to third generation cephalosporins by Enterobacteriaceae causing community-onset urinary tract infections in hospitals in Colombia]. / Emergencia de fenotipos resistentes a cefalosporinas de tercera generación en Enterobacteriaceae causantes de infección del tracto urinario de inicio comunitario en hospitales de Colombia.

INTRODUCTION: Urinary tract infection (UTI) is a common disease in the community, and a matter of concern due to the increasing resistance of microorganisms to first line antibiotics and the emergence of multiresistant strains producing extended spectrum beta lactamases (ESBL) in the community. METHODS: An analytical case-control study was conducted over twelve months in 9 hospitals in Colombia. We collected isolates of E. coli, Klebsiella spp. and Proteus spp. from patients with community-onset UTI. The presence of ESBL, AmpC and KPC beta-lactamases were characterized by microbiological and molecular methods. The aim of this study was to determine factors related to the presence of these mechanisms of the resistance to third generation cephalosporins. RESULTS: A total of 325 isolates (287 E. coli, 29 Klebsiella spp. and 9 Proteus spp.) were included. The most frequent comorbidities among the patients were hypertension (n=82; 25.2%) and diabetes mellitus (n=68; 20.9%). Previous use of antimicrobials was found in 23% of patients, and 29% had a previous UTI. Resistance to third and fourth generation cephalosporins varied between 3.4% and 6.3% in E. coli and between 6.9% and 17.8% in K. pneumoniae. Seven (2.4%) CTX-M-15 ESBL-producing E. coli isolates were detected; four of them belonged to ST 131 clone. In K. pneumoniae we detected three KPC-3 carbapenemases (10.3%). CONCLUSIONS: This study confirms the emergence of resistance to third generation cephalosporins enterobacteriaceae as a cause of community-onset UTI. We emphasize the presence of ST 131 clone and KPC carbapenemases circulating in Colombia outside the hospital environment.

Characterization of extended spectrum ß-lactamases in Colombian clinical isolates of non-typhoidal Salmonella enterica between 1997 and 2022 / Caracterización de ß-lactamasas de espectro extendido en aislamientos clínicos colombianos de Salmonella enterica no tifoidea de 1997 a 2022.

Introduction. Salmonella spp. is a zoonotic pathogen transmitted to humans through contaminated water or food. The presence of extended-spectrum ß-lactamases is a growing public health problem because these enzymes are resistant to third and fourth generation cephalosporins. Objective. To characterize extended-spectrum ß-lactamases in Salmonella spp. isolates received by the acute diarrheal disease/foodborne disease surveillance program of the Grupo de Microbiología of the Instituto Nacional de Salud. Materials and methods. A total of 444 Salmonella spp. isolates, resistant to at least one of the cephalosporins, were obtained between January 1997 and June 2022. The extendedspectrum ß-lactamases phenotype was identified by the double disk test. DNA extraction was carried out by the boiling method, and the blaCTX-M, blaSHV, and blaTEM genes were amplified by PCR. Results. All the isolates were positive for the extended-spectrum ß-lactamases test. The genes identified were: blaCTX-M + blaTEM (n=200), blaCTX-M (n=177), blaSHV (n=16), blaSHV + blaCTX-M (n=6), blaTEM (n=13) and blaSHV + blaCTX-M + blaTEM (n=3). Twenty-six isolates were negative for the evaluated genes. Positive extended-spectrum ß-lactamases isolates were identified in Bogotá and 21 departments: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusion. Resistance to third generation cephalosporins in Salmonella spp. isolates was mainly caused by blaCTX-M. Isolates were resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole (44 %; 197/444). The most frequent extended-spectrum ß-lactamases-expressing serotypes were Salmonella Typhimurium and Salmonella Infantis.

Introducción. Salmonella spp. es un agente patógeno zoonótico transmitido al humano por el agua o los alimentos contaminados. La presencia de ß-lactamasas de espectro extendido es un creciente problema para la salud pública debido a que estas enzimas confieren resistencia contra las cefalosporinas de tercera y cuarta generación. Objetivo. Caracterizar las ß-lactamasas de espectro extendido en aislamientos de Salmonella spp. recibidos por el programa de vigilancia de enfermedad diarreica aguda o enfermedad transmitida por alimentos del Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Entre enero de 1997 y junio de 2022, se recibieron 444 aislamientos de Salmonella spp. resistentes, por lo menos, a una de las cefalosporinas de tercera generación. El fenotipo de las ß-lactamasas de espectro extendido se identificó con la prueba de doble disco. El ADN se extrajo por ebullición y mediante PCR se amplificaron los genes blaCTX-M, blaSHV y blaTEM. Resultados. Todos los aislamientos fueron positivos para la prueba de ß-lactamasas de espectro extendido. Los resultados de la amplificación por PCR fueron: blaCTX-M + blaTEM (n=200), blaCTX-M (n=177), blaSHV (n=16), blaSHV + blaCTX-M (n=6), blaTEM (n=13) y blaSHV + blaCTX-M + blaTEM (n=3). Del total, 26 aislamientos fueron negativos para los genes evaluados. Los aislamientos positivos para ß-lactamasas de espectro extendido se identificaron en Bogotá y en 21 departamentos: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusión. La resistencia a las cefalosporinas de tercera generación en aislamientos de Salmonella spp. fue generada principalmente por blaCTX-M. El 44 % (197/444) de los aislamientos presentó resistencia a ampicilina, tetraciclina, cloranfenicol y trimetoprimsulfametoxazol Los serotipos portadores de ß-lactamasas de espectro extendido más frecuentes fueron S. Typhimurium y S. Infantis.

Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country.

Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

Caracterización de ß-lactamasas de espectro extendido en aislamientos clínicos colombianos de Salmonella enterica no tifoidea de 1997 a 2022 / Characterization of extended spectrum ß-lactamases in Colombian clinical isolates of non-typhoidal Salmonella enterica between 1997 and 2022

Introducción. Salmonella spp. es un agente patógeno zoonótico transmitido al humano por el agua o los alimentos contaminados. La presencia de ß-lactamasas de espectro extendido es un creciente problema para la salud pública debido a que estas enzimas confieren resistencia contra las cefalosporinas de tercera y cuarta generación. Objetivo. Caracterizar las ß-lactamasas de espectro extendido en aislamientos de Salmonella spp. recibidos por el programa de vigilancia de enfermedad diarreica aguda o enfermedad transmitida por alimentos del Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Entre enero de 1997 y junio de 2022, se recibieron 444 aislamientos de Salmonella spp. resistentes, por lo menos, a una de las cefalosporinas de tercera generación. El fenotipo de las ß-lactamasas de espectro extendido se identificó con la prueba de doble disco. El ADN se extrajo por ebullición y mediante PCR se amplificaron los genes bla CTX-M, bla SHVy : ' a ILM. Resultados. Todos los aislamientos fueron positivos para la prueba de ß-lactamasas de espectro extendido. Los resultados de la amplificación por PCR fueron: bla CTX-M + bla TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) y bla SHV + bla CTX-M + bla TLM (n=3). Del total, 26 aislamientos fueron negativos para los genes evaluados. Los aislamientos positivos para ß-lactamasas de espectro extendido se identificaron en Bogotá y en 21 departamentos: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusión. La resistencia a las cefalosporinas de tercera generación en aislamientos de Salmonella spp. fue generada principalmente por bla CTX-M. El 44 % (197/444) de los aislamientos presentó resistencia a ampicilina, tetraciclina, cloranfenicol y trimetoprim- sulfametoxazol Los serotipos portadores de ß-lactamasas de espectro extendido más frecuentes fueron S. Typhimurium y S. Infantis.

Introduction. Salmonella spp. is a zoonotic pathogen transmitted to humans through contaminated water or food. The presence of extended-spectrum ß-lactamases is a growing public health problem because these enzymes are resistant to third and fourth generation cephalosporins. Objective. To characterize extended-spectrum ß-lactamases in Salmonella spp. isolates received by the acute diarrheal disease/foodborne disease surveillance program of the Grupo de Microbiología of the Instituto Nacional de Salud. Materials and methods. A total of 444 Salmonella spp. isolates, resistant to at least one of the cephalosporins, were obtained between January 1997 and June 2022. The extended- spectrum ß-lactamases phenotype was identified by the double disk test. DNA extraction was carried out by the boiling method, and the bla CTX-M, bla SHV, and bla TLM genes were amplified by PCR. Results. All the isolates were positive for the extended-spectrum ß-lactamases test. The genes identified were: bla CTX-M + ba TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) and bla SHV + bla CTX-M + bla TLM (n=3). Twenty-six isolates were negative for the evaluated genes. Positive extended-spectrum ß-lactamases isolates were identified in Bogotá and 21 departments: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusion. Resistance to third generation cephalosporins in Salmonella spp. isolates was mainly caused by bla CTX-M. Isolates were resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole (44 %; 197/444). The most frequent extended-spectrum ß-lactamases-expressing serotypes were Salmonella Typhimurium and Salmonella Infantis.

Results of the national surveillance of antimicrobial resistance of Enterobacteriaceae and Gram negative bacilli in health care-associated infections in Colombia, 2012-2014.

INTRODUCTION: The Colombian National Antimicrobial Resistance Monitoring System for the surveillance of healthcare-associated infections was set up to meet this problem in the third quarter of 2012. OBJECTIVE: To describe resistance profiles and laboratory-based surveillance based on the information collected by the System. MATERIALS AND METHODS: We conducted a retrospective and descriptive study of the information notified to the Colombian Public Health Surveillance System (Sivigila), and in the Whonet databases covering the period from July 2012 to December 2014 provided by the primary data-generating units in the country, as well as laboratory surveillance results from 1,642 phenotypic and genotypic tests on carbapenemase isolates (927 from Enterobacteriaceae, 614 from Pseudomonas spp. and 101 from Acinetobacter spp.). RESULTS: There was a significant increase in Escherichia coli resistance to third-generation cephalosporins (reaching 26.3% in ICUs and 22.5% in other hospital wards), and Klebsiella pneumoniae resistance to ertapenem also increased (reaching 14.6% in ICUs). Acinetobacter baumannii carbapenem resistance exceeded 50% in ICUs whereas Pseudomonas aeruginosa had lower carbapenem resistance (38.8%). KPC (n = 574) and NDM (n=57) were the most frequently occurring carbapenemases in Enterobacteriaceae, VIM (n=229) and KPC (n=114) in P. aeruginosa, and OXA-23 in A. baumannii (n=87); several carbapenemase combinations were identified, KPC + VIM being the most common in Pseudomonas spp. and Enterobacteriaceae. CONCLUSION: The data from the surveillance of healthcare-associated infections revealed significant carbapenem resistance profiles and antimicrobial resistance mechanisms circulating in Colombian healthcare institutions.

Whole-Genome Sequence of a Colombian Acinetobacter baumannii Strain, a Coproducer of OXA-72 and OXA-255-Like Carbapenemases.

Colombian Acinetobacter baumannii strain ST920 was isolated from the sputum of a 68-year-old male patient. This isolate possessed blaOXA-72 and blaOXA-255-like genes. The assembled genome contained 4,104,098 pb and 38.79% G+C content. This is the first case reported of the coproduction (blaOXA-72 and blaOXA-255-like) of carbapenem-hydrolyzing class D ß-lactamases (CHDLs) in Acinetobacter baumannii.

Phenotypic and genotypic characterization of Neisseria meningitidis serogroup B isolates from Cartagena, Colombia, 2012-2014.

INTRODUCTION: Neisseria meningitidis is one of the leading causes of bacterial meningitis. In 2013, an increase in invasive disease caused by N. meningitidis serogroup B occurred in Cartagena, Colombia. OBJECTIVE: The aim of this study was to characterize serogroup B isolates recovered from patients with meningococcal meningitis in Cartagena during 2012 and 2014. MATERIALS AND METHODS: Twenty-five isolates were collected through a national, laboratory-based surveillance, and phenotypic and genotypic characteristics were determined by serosubtyping, serotyping, antimicrobial susceptibility testing, repetitive sequence-based PCR (rep-PCR). MLST data available were also used. RESULTS: The B:10,15:nt phenotype, associated with clonal complex ST-41/44, was responsible for 68.0% of all cases. CONCLUSION: The clinical, epidemiological and molecular characterization of meningococcal disease is necessary for understanding the spread of virulent meningococcal clones and for facilitating the early detection of cases to reduce epidemic risks.

[Characterization of isolates of carbapenemase-producing Pseudomonas aeruginosa from seven Colombian provinces]. / Caracterización de aislamientos de Pseudomonas aeruginosa productores de carbapenemasas de siete departamentos de Colombia.

INTRODUCTION: Pseudomonas aeruginosa is an opportunistic pathogen that causes multiple infections in hospitalized patients. This microorganism has developed resistance to several antimicrobial agents, including carbapenems, which are considered to be the last therapeutic option against these infections. Carbapenem resistance of P. aeruginosa is mediated by different mechanisms: Carbapenemases class B (MBL) and A, alterations in the OprD expression and overexpression of the Mex efflux pump. OBJECTIVE: To describe the presence of carbapenemases in P. aeruginosa isolates from seven Colombian provinces. MATERIALS AND METHODS: A total of 57 P. aeruginosa isolates were collected between September 2012 and March 2013 from national surveillance in Colombia and were sent to the Grupo de Microbiología at the Instituto Nacional de Salud (INS) for evaluation. Iidentification and antimicrobial susceptibility were confirmed through automated method (Vitek ® 2) and disk diffusion (Kirby-Bauer) according to the Clinical and Laboratory Standards Institute, CLSI, 2013. Phenotypic and genotypic confirmation was determined using the modified Hodge test (MHT), a synergism test using imipenem, EDTA-SMA and meropenem, and conventional PCR to detect the bla KPC, bla VIM, bla IMP and bla NDM genes. RESULTS: Of the 57 isolates, two showed sensitivity to carbapenems. Forty-three isolates were positive for carbapenemases with a high percentage of sensitivity to colistin (76.4%, n=42). The 43 isolates producing carbapenemases showed multiple drug resistance: 72.1% were positive in the MHT and 79.1% showed MBL synergism. PCR amplification confirmed that 33 isolates were positive for bla VIM, nine were positive for bla KPC and one isolate expressed both KPC and VIM carbapenemases. No isolates showed amplified products with bla IMP and bla NDM primers. CONCLUSIONS: The most frequent carbapenemase was VIM, followed by KPC in an approximate ratio of 3:1.

Early dissemination of OXA-72-producing Acinetobacter baumannii strain in Colombia: a case report.

Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.

[The spread of KPC-3 Klebsiella pneumoniae in hospitals in Bogotá over a three-year period (2008-2010)]. / Diseminación de Klebsiella pneumoniae productoras de KPC-3 en hospitales de Bogotá durante un periodo de tres años.

UNLABELLED: Introduction : One of the major worldwide public health problems today are the infections caused by carbapenem-resistant Enterobacteriaceae (CRE), among which carbapenem-resistant Klebsiella pneumoniae (CRKP), constitutes one of the most common pathogens causing nosocomial infection. OBJECTIVE: This study was aimed at describing the dissemination of KPC-3 enzyme-producing Klebsiella pneumoniae in clinical isolates from hospitals in Bogotá. MATERIALS AND METHODS: Eighty-two CRKP isolates collected from 10 hospitals in Bogotá from 2008-2010 were analysed; disk diffusion and microdilution were used for phenotypic detection of enzymes and PCR for genotyping. Automated and manual methods were used for determining profiles for antimicrobial susceptibility testing (AST) with 13 agents. PFGE was used for obtaining the isolates´ genetic relationship. RESULTS: This study gives an overview of CRKP patterns in 10 hospitals in Bogota which were found to present resistance to multiple antibiotic families. The CRKPs were grouped in different clones, each having different subtypes, and were spread in the 10 hospitals over the three-year period (2008-2010). CONCLUSIONS: The dissemination of KPC-3-producing Klebsiella pneumoniae nosocomial isolates in Bogota highlights the need for strengthening epidemiological surveillance against this type of microorganism and the development of specific priority activities for preventing and controlling such infection.

Resultados de la vigilancia nacional de la resistencia antimicrobiana de enterobacterias y bacilos Gram negativos no fermentadores en infecciones asociadas a la atención de salud, Colombia, 2012-2014 / Results of the national surveillance of antimicrobial resistance of Enterobacteriaceae and Gram negative bacilli in health care-associated infections in Colombia, 2012-2014

Resumen Introducción. En el tercer trimestre de 2012, comenzó a operar el Sistema Nacional de Vigilancia de Resistencia Antimicrobiana en las infecciones asociadas a la atención en salud, con el fin de recabar y analizar la información referente al problema en Colombia. Objetivo. Describir los perfiles de resistencia y los resultados de la vigilancia por el laboratorio con base en los datos recolectados en el Sistema. Materiales y métodos. Se hizo un estudio descriptivo y retrospectivo con base en la información del Sistema Nacional de Vigilancia en Salud Pública, Sivigila, 1 de septiembre de 2012 a 31 de diciembre de 2014, así como de las bases de datos Whonet con los datos notificados por las unidades primarias generadoras de datos y los resultados de la confirmación por el laboratorio de la caracterización fenotípica y genotípica de la resistencia a carbapenemasas en 1.642 aislamientos (927 de enterobacterias, 614 de Pseudomonas spp. y 101 de Acinetobacter spp.). Resultados. La resistencia de Escherichia coli a las cefalosporinas de tercera generación presentó un incremento significativo, alcanzando 26,3 % en unidades de cuidados intensivos y 22,5 % en otras áreas de hospitalización. La resistencia a ertapenem de Klebsiella pneumoniae registró un incremento y alcanzó 14,6 % en unidades de cuidados intensivos. La resistencia de Acinetobacter baumannii a los carbapenémicos superó el 50 % en dichas unidades, en tanto que en Pseudomonas aeruginosa se presentaron porcentajes más bajos (38,8 %). Las carbapenemasas más frecuentes en enterobacterias fueron la KPC (n=574), seguida de la NDM (n=57); en P. aeruginosa, la VIM (n=229) y la KPC (n=114), y en A. baumannii, la OXA-23 (n=87). Se detectaron varias combinaciones de carbapenemasas, siendo la de KPC y VIM la más frecuente en Pseudomonas spp., y en enterobacterias. Conclusión. La información obtenida a partir del Sistema Nacional de Vigilancia ha permitido conocer los perfiles y los mecanismos de resistencia a carbapenémicos de las cepas que están circulando en las instituciones de salud del país.

Abstract Introduction: The Colombian National Antimicrobial Resistance Monitoring System for the surveillance of healthcare-associated infections was set up to meet this problem in the third quarter of 2012. Objective: To describe resistance profiles and laboratory-based surveillance based on the information collected by the System. Materials and methods: We conducted a retrospective and descriptive study of the information notified to the Colombian Public Health Surveillance System (Sivigila), and in the Whonet databases covering the period from July 2012 to December 2014 provided by the primary data-generating units in the country, as well as laboratory surveillance results from 1,642 phenotypic and genotypic tests on carbapenemase isolates (927 from Enterobacteriaceae, 614 from Pseudomonas spp. and 101 from Acinetobacter spp.). Results: There was a significant increase in Escherichia coli resistance to third-generation cephalosporins (reaching 26.3% in ICUs and 22.5% in other hospital wards), and Klebsiella pneumoniae resistance to ertapenem also increased (reaching 14.6% in ICUs). Acinetobacter baumannii carbapenem resistance exceeded 50% in ICUs whereas Pseudomonas aeruginosa had lower carbapenem resistance (38.8%). KPC (n = 574) and NDM (n=57) were the most frequently occurring carbapenemases in Enterobacteriaceae, VIM (n=229) and KPC (n=114) in P. aeruginosa, and OXA-23 in A. baumannii (n=87); several carbapenemase combinations were identified, KPC + VIM being the most common in Pseudomonas spp. and Enterobacteriaceae. Conclusion: The data from the surveillance of healthcare-associated infections revealed significant carbapenem resistance profiles and antimicrobial resistance mechanisms circulating in Colombian healthcare institutions.

Early dissemination of OXA-72-producing Acinetobacter baumannii strain in Colombia: a case report

Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.