The emergence of multidrug-resistant strains is a major health problem especially for countries with high TB incidence such as Peru. In this study, we evaluated High Resolution Melting (HRM) assay in Peruvian isolates for the detection of mutations within rpoB, katG genes and promoter region inhA to determine isoniazid and rifampicin resistance in Mycobacterium tuberculosis (Mtb). DNA samples extracted from a total of 167 clinical isolates of Mtb, 89 drug-sensitive and 78 multidrug-resistant, were blindly analyzed by HRM analysis and verified by DNA sequencing. The HRM analysis generated patterns that were specific to distinguish between sensitive and resistance isolates. The sensitivity and specificity of the HRM assays in comparison with drug susceptibility testing (DST) for detection of rifampicin resistance were 98.7 % and 97.5 %, and for isoniazid resistance were 98.7 % and 100 %. This study suggests that HRM Analysis could help with rapid diagnosis of MDR-TB cases in Peru.

Peru holds the fourth highest burden of tuberculosis in the Americas. Despite an apparently well-functioning DOTS control program, the prevalence of multidrug resistant tuberculosis (MDR-TB) continues to increase. To worsen this situation, cases of extensively drug resistance tuberculosis (XDR-TB) have been detected. Little information exists about the genetic diversity of drug-susceptible vs. MDR-TB and XDR-TB. Cryopreserved samples of XDR strains from 2007 to 2009 (second semester), were identified and collected. Starting from 227 frozen samples, a total of 142 XDR-TB strains of Mycobacterium tuberculosis complex (MTBC; 1 isolate per patient) were retained for this study. Each strain DNA was analyzed by spoligotyping and the 15-loci Mycobacterial Interspersed Repetitive Unit (MIRU-15). Among the 142 isolates analyzed, only 2 samples (1.41%) could not be matched to any lineage. The most prevalent sublineage was Haarlem (43.66%), followed by T (27.46%), LAM (16.2%), Beijing (9.15%), and X clade (1.41%). Spoligotype analysis identified clustering for 128/142 (90.1%) isolates vs. 49/142 (34.5%) with MIRUs. Of the samples, 90.85% belonged to retreated patients. The drug resistant profile demonstrated that 62.67% showed resistance to injectable drugs capreomycin (CAP) and kanamycin (KAN) vs. 15.5% to CAP alone and 21.8% to KAN alone. The SIT219/T1 and SIT50/H3 were the most prevalent patterns in our study. The spoligoforest analysis showed that SIT53/T1 was at the origin of many of the T lineage strains as well as a big proportion of Haarlem lineage strains (SIT50/H3, followed by SIT47/H1, SIT49/H3, and SIT2375/H1), as opposed to the SIT1/Beijing strains that did not appear to evolve into minor Beijing sublineages among the XDR-TB strains. In contrast with other Latin-American countries where LAM sublineage is the most predominant, we found the Haarlem to be the most common followed by T sublineage among the XDR-TB strains.

Objectives. This study aimed to evaluate the prevalence and distribution of dengue virus genotype V serotype 1 (DENV-1) and cosmopolitan genotype serotype 2 (DENV-2) in Peru between 2019 and 2022. Materials and methods. The envelope (E) gene region was amplified from 79 serum samples by polymerase chain reaction (PCR) and sequenced by next-generation sequencing (NGS) technology. The obtained sequences were subsequently analyzed with bioinformatics tools. Results. The study generated envelope gene sequences of DENV-1 and DENV-2 serotypes. Our study revealed a rapid dispersal and wide distribution of the cosmopolitan DENV-2 genotype in several regions of Peru in 2022, as well as the spread of DENV-1 genotype V to new Peruvian regions, along with the cosmopolitan DENV-2 genotype. Conclusions. Our findings suggest the urgent need to strengthen epidemiological and genomic surveillance systems to understand and control the spread of circulating DENV genotypes in Peru. This will allow a more rapid response, as well as the monitoring of its potential dissemination to other countries in the Americas.

The Genotype®MTBDRplus molecular test is a method that allows identification of the most frequent mutations associated with resistance to major first-line antituberculosis drugs, Isoniazid (INH) and Rifampicin (RFP). The aim of this study was to evaluate the performance of the molecular test with culture and smear- positive sputum samples. We evaluated 95 cultures and 100 sputum samples with resistance profiles previously determined by the reference method "Agar Plate Proportions" (APP). The molecular test from cultures showed a sensitivity of 100 %, 97,5 % and 96,97 % for RIF, INH and MDR respectively while from sputums the sensitivity was 95,65 %, 96,77 % and 95,24 % for RIF, INH and MDR respectively. We conclude that the molecular test Genotype®MTBDRplus is a very useful tool to detect resistance to isoniazid and rifampicin simultaneously (MDR-TB) in up to 72 hours from sputum samples or cultures.

Introducción. La aparición de enterobacterias multirresistentes y productoras de betalactamasas de espectro extendido en pacientes ambulatorios con infecciones urinarias representa un problema de salud pública en Perú.Objetivo. Comparar los perfiles de resistencia de Escherichia coli uropatógenas e identificar los fenotipos de cepas productoras de betalactamasas de espectro extendido en tres establecimientos privados de salud localizados en las regiones de la costa, la sierra y la selva de Perú.Materiales y métodos. Se llevó a cabo durante el 2016 un estudio descriptivo de 98 muestras de orina de pacientes con infección urinaria, 35 procedentes de Lima (costa), 38 de Juliaca (sierra) y 25 de Iquitos (selva), en el que se determinó la sensibilidad antimicrobiana utilizando ocho discos antibióticos.Asimismo, se evaluó la producción de betalactamasas de espectro extendido con discos de cefotaxima, de ceftazidima o de su combinación, con ácido clavulánico en agar Mueller-Hinton.Resultados. Se identificaron 18 perfiles de resistencia que incluían desde los sensibles a todos los antibióticos hasta los resistentes simultáneamente a siete antibióticos, con el 18,4 % de aislamientos resistentes a un antibiótico y el 54,0 % de multirresistentes. Se detectó producción de betalactamasas en el 28,6 % de las cepas procedentes de la región de Puno. También, se observó un mayor número de casos en el rango de edad de 31 a 45 años con resistencia a ceftazidima, ceftriaxona, gentamicina y trimetoprim-sulfametoxazol en el establecimiento de salud de Puno.Conclusión. Los perfiles de resistencia variaron según la localización geográfica del establecimiento de salud.

Con el objetivo de determinar la presencia de enterobacterias productoras de betalactamasas (bla) en muestras de efluentes hospitalarios, se realizó un estudio en dos hospitales de nivel II y III de Lima, Perú. Se identificó y caracterizó el perfil de resistencia de las bacterias aisladas mediante el sistema MicroScan para 18 antimicrobianos, y mediante PCR convencional se determinó la presencia de los genes de resistencia a betalactamasas de espectro de extendido (BLEE) (blaCTX-M, blaSHV, blaTEM, blaPER) y carbapenemasas (blaKPC, blaNDM, blaVIM, blaIMP). Se identificó 32 aislados (20 enterobacterias y 12 bacterias gramnegativas). Todas las bacterias aisladas presentaron multirresistencia. Se halló la presencia de genes BLEE (blaTEM) y carbapenemasas (blaKPC e blaIMP) en los hospitales evaluados. La liberación de estos microorganismos a la vía pública y la falta de tratamiento de los efluentes hospitalarios podría ser un importante problema de salud pública.