Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Hospitalized Patients in Peru.

There is a knowledge gap in the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) causing bloodstream infections (BSIs) in Peru. Through a surveillance study in 13 hospitals of 10 Peruvian regions (2017-2019), we assessed the proportion of MRSA among S. aureus BSIs as well as the molecular typing of the isolates. A total of 166 S. aureus isolates were collected, and 36.1% of them were MRSA. Of note, MRSA isolates with phenotypic and genetic characteristics of the hospital-associated Chilean-Cordobes clone (multidrug-resistant SCCmec I, non-Panton-Valentine leukocidin [PVL] producers) were most commonly found (70%), five isolates with genetic characteristics of community-associated MRSA (CA-MRSA)-SCCmec IV, PVL-producer-(8.3%) were seen in three separate regions. These results demonstrate that hospital-associated MRSA is the most frequent MRSA found in patients with BSIs in Peru. They also show the emergence of S. aureus with genetic characteristics of CA-MRSA. Further studies are needed to evaluate the extension of CA-MRSA dissemination in Peru.

Prevalence of Antimicrobial Resistance in Gram-Negative Bacteria Bloodstream Infections in Peru and Associated Outcomes: VIRAPERU Study.

Surveillance of antimicrobial resistance among gram-negative bacteria (GNB) is of critical importance, but data for Peru are not available. To fill this gap, a non-interventional hospital-based surveillance study was conducted in 15 hospitals across Peru from July 2017 to October 2019. Consecutive unique blood culture isolates of key GNB (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp.) recovered from hospitalized patients were collected for centralized antimicrobial susceptibility testing, along with linked epidemiological and clinical data. A total of 449 isolates were included in the analysis. Resistance to third-generation cephalosporins (3GCs) was present in 266 (59.2%) GNB isolates. Among E. coli (n = 199), 68.3% showed 3GC resistance (i.e., above the median ratio for low- and middle-income countries in 2020 for this sustainable development goal indicator). Carbapenem resistance was present in 74 (16.5%) GNB isolates, with wide variation among species (0% in E. coli, 11.0% in K. pneumoniae, 37.0% in P. aeruginosa, and 60.8% in Acinetobacter spp. isolates). Co-resistance to carbapenems and colistin was found in seven (1.6%) GNB isolates. Empiric treatment covered the causative GNB in 63.3% of 215 cases. The in-hospital case fatality ratio was 33.3% (92/276). Pseudomonas aeruginosa species and carbapenem resistance were associated with higher risk of in-hospital death. In conclusion, an important proportion of bloodstream infections in Peru are caused by highly resistant GNB and are associated with high in-hospital mortality.

Frequency of community-acquired methicilin-resistant Staphylococcus aureus in a tertiary care hospital in Peru. / Frecuencia de Staphylococcus aureus meticilinorresistente adquirido en la comunidad en un hospital de tercer nivel en Perú.

In order to determine the frequency of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates and to describe the antimicrobial resistance pattern and genotype, a cross-sectional study was conducted in 2017 at the Hospital Nacional Cayetano Heredia in Lima, Peru. We found a MRSA prevalence of 46.1% in the 115 analyzed S. aureus isolates; most were reported from different secretions (26.4%) and blood (18.9%). We found high co-resistance (>75%) to clindamycin, erythromycin, gentamicin and ciprofloxacin. Regarding SSCmec typification, most of the isolates were identified as hospital-acquired MRSA (HA-MRSA) and a minority of them as CA-MRSA (2.6%). Despite its low prevalence when compared to other Latin American countries (27%), epidemiological surveillance is recommended to control local CA-MRSA dissemination.

Con el objetivo de determinar la frecuencia de aislamientos de Staphylococcus aureus meticilinorresistente adquirido en la comunidad (MRSA-AC) y describir el patrón de resistencia antimicrobiana y de genotipo, se realizó un estudio transversal en el 2017 en el Hospital Nacional Cayetano Heredia en Lima, Perú. De los 115 aislamientos de S. aureus analizados, se determinó una frecuencia de MRSA del 46,1%, la mayoría provenientes de secreciones de diferentes tipos (26,4%) y sangre (18,9%). Se encontró alta corresistencia (>75%) a clindamicina, eritromicina, gentamicina y ciprofloxacina entre los aislamientos de MRSA. Según la tipificación de SCCmec, la mayoría correspondían a cepas de MRSA adquirido en un hospital (MRSA-AH) y, solo un pequeño grupo (2,6%) correspondían a MRSA-AC. A pesar de la baja frecuencia descrita con relación a países vecinos (27%), es necesario mantener una adecuada vigilancia epidemiológica local para evitar la propagación local de MRSA-AC.

Frecuencia de Staphylococcus aureus meticilinorresistente adquirido en la comunidad en un hospital de tercer nivel en Perú

Con el objetivo de determinar la frecuencia de aislamientos de Staphylococcus aureus meticilinorresistente adquirido en la comunidad (MRSA-AC) y describir el patrón de resistencia antimicrobiana y de genotipo, se realizó un estudio transversal en el 2017 en el Hospital Nacional Cayetano Heredia en Lima, Perú. De los 115 aislamientos de S. aureus analizados, se determinó una frecuencia de MRSA del 46,1%, la mayoría provenientes de secreciones de diferentes tipos (26,4%) y sangre (18,9%). Se encontró alta corresistencia (>75%) a clindamicina, eritromicina, gentamicina y ciprofloxacina entre los aislamientos de MRSA. Según la tipificación de SCCmec, la mayoría correspondían a cepas de MRSA adquirido en un hospital (MRSA-AH) y, solo un pequeño grupo (2,6%) correspondían a MRSA-AC. A pesar de la baja frecuencia descrita con relación a países vecinos (27%), es necesario mantener una adecuada vigilancia epidemiológica local para evitar la propagación local de MRSA-AC.

In order to determine the frequency of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates and to describe the antimicrobial resistance pattern and genotype, a cross-sectional study was conducted in 2017 at the Hospital Nacional Cayetano Heredia in Lima, Peru. We found a MRSA prevalence of 46.1% in the 115 analyzed S. aureus isolates; most were reported from different secretions (26.4%) and blood (18.9%). We found high co-resistance (>75%) to clindamycin, erythromycin, gentamicin and ciprofloxacin. Regarding SSCmec typification, most of the isolates were identified as hospital-acquired MRSA (HA-MRSA) and a minority of them as CA-MRSA (2.6%). Despite its low prevalence when compared to other Latin American countries (27%), epidemiological surveillance is recommended to control local CA-MRSA dissemination.

Characterization of ESBL-Producing Salmonella enterica Serovar Infantis Infection in Humans, Lima, Peru.

Salmonella enterica serovar Infantis is causing an increasing number of infections worldwide. Our aim was to describe the characteristics of S. enterica serovar Infantis among patients attended in a hospital of Lima, Peru. Fifty cases of salmonellosis were seen during October 2015-May 2017; Salmonella Infantis was detected in 36% (n = 18) of them, displacing Enteritidis and Typhimurium (n = 13, 26%, each). Seventeen cases caused by Salmonella Infantis were presented as diarrheal illnesses; only one extraintestinal case (bacteremia) was seen in a 1-year-old infant. This serovar is resistant to multiple groups of antimicrobials, showing only fully susceptibility to carbapenems. Compared with Infantis, other serovars analyzed (mainly Enteritidis and Typhimurium) showed a lower frequency of resistance to antimicrobials such as trimethoprim-sulfamethoxazole, ampicillin, and chloramphenicol. The antibiotic with the highest frequency of resistance was ciprofloxacin. Further studies are needed to evaluate the routes of transmission and measures of control of this multidrug-resistant Salmonella.

Characterization of Salmonella enterica isolates causing bacteremia in Lima, Peru, using multiple typing methods.

In this study, different molecular typing tools were applied to characterize 95 Salmonella enterica blood isolates collected between 2008 and 2013 from patients at nine public hospitals in Lima, Peru. Combined results of multiplex PCR serotyping, two- and seven-loci multilocus sequence typing (MLST) schemes, serotyping, IS200 amplification and RAPD fingerprints, showed that these infections were caused by eight different serovars: Enteritidis, Typhimurium, Typhi, Choleraesuis, Dublin, Paratyphi A, Paratyphi B and Infantis. Among these, Enteritidis, Typhimurium and Typhi were the most prevalent, representing 45, 36 and 11% of the isolates, respectively. Most isolates (74%) were not resistant to ten primarily used antimicrobial drugs; however, 37% of the strains showed intermediate susceptibility to ciprofloxacin (ISC). Antimicrobial resistance integrons were carried by one Dublin (dfra1 and aadA1) and two Infantis (aadA1) isolates. The two Infantis isolates were multidrug resistant and harbored a large megaplasmid. Amplification of spvC and spvRA regions showed that all Enteritidis (n = 42), Typhimurium (n = 34), Choleraesuis (n = 3) and Dublin (n = 1) isolates carried the Salmonella virulence plasmid (pSV). We conclude that the classic serotyping method can be substituted by the multiplex PCR and, when necessary, sequencing of only one or two loci of the MLST scheme is a valuable tool to confirm the results. The effectiveness and feasibility of different typing tools is discussed.

Colonización por enterococo resistente a vancomicina en pacientes internados en un hospital de Lima, Perú / Colonization by Enterococcal Strains Resistant to Vancomycin in Patients from a Hospital in Lima, Peru

RESUMEN Con el objetivo de determinar la frecuencia de colonización por el enterococo resistente a vancomicina (ERV), el genotipo de resistencia y los factores asociados, se realizó un estudio de tipo transversal durante noviembre y diciembre del 2013 en el Hospital Nacional Cayetano Heredia en Lima, Perú. Se encontró una frecuencia de colonización por ERV de 6,2% (IC 95%: 1,67-10,73), todas las cepas aisladas tenían el genotipo de resistencia vanA, y se halló que las variables hospitalización previa (p=0,001) y el uso de cefalosporinas de tercera generación (p=0,016) estaban asociadas a la colonización por ERV. En conclusión, existe colonización perianal por ERV en los diversos servicios de hospitalización, el gen vanA podría ser transmitido a gérmenes más virulentos y ocasionar la aparición de la bacteria Staphylococcus aureus resistente a vancomicina (VRSA). Es necesario adoptar medidas de control de infecciones para evitar la transmisión de esta bacteria en el ambiente hospitalario.

ABSTRACT This cross-sectional study was conducted from November to December of 2013 at the Cayetano Heredia National Hospital in Lima, Peru, to determine the rate of infection with vancomycin-resistant enterococcus (VRE), the resistance genotype, and associated factors. The rate of infection with VRE was 6.2% (95% confidence interval [CI]: 1.67-10.73) and the resistance genotype isolated from all strains was the vanA gene. The factors associated with colonization with VRE were previous hospitalizations (p = 0.001) and the use of third-generation cephalosporins (p = 0.016). In conclusion, perianal colonization with VRE is present in many hospital services. Moreover, the vanA gene may cause resistance to vancomycin and promote the development of vancomycin-resistant Staphylococcus aureus. Therefore, infection control measures should be adopted to prevent the dissemination of this bacterial strain in hospital settings.

Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment.

[Colonization by Enterococcal Strains Resistant to Vancomycin in Patients from a Hospital in Lima, Peru]. / Colonización por enterococo resistente a vancomicina en pacientes internados en un hospital de Lima, Perú.

This cross-sectional study was conducted from November to December of 2013 at the Cayetano Heredia National Hospital in Lima, Peru, to determine the rate of infection with vancomycin-resistant enterococcus (VRE), the resistance genotype, and associated factors. The rate of infection with VRE was 6.2% (95% confidence interval [CI]: 1.67-10.73) and the resistance genotype isolated from all strains was the vanA gene. The factors associated with colonization with VRE were previous hospitalizations (p = 0.001) and the use of third-generation cephalosporins (p = 0.016). In conclusion, perianal colonization with VRE is present in many hospital services. Moreover, the vanA gene may cause resistance to vancomycin and promote the development of vancomycin-resistant Staphylococcus aureus. Therefore, infection control measures should be adopted to prevent the dissemination of this bacterial strain in hospital settings.

Con el objetivo de determinar la frecuencia de colonización por el enterococo resistente a vancomicina (ERV), el genotipo de resistencia y los factores asociados, se realizó un estudio de tipo transversal durante noviembre y diciembre del 2013 en el Hospital Nacional Cayetano Heredia en Lima, Perú. Se encontró una frecuencia de colonización por ERV de 6,2% (IC 95%: 1,67-10,73), todas las cepas aisladas tenían el genotipo de resistencia vanA, y se halló que las variables hospitalización previa (p=0,001) y el uso de cefalosporinas de tercera generación (p=0,016) estaban asociadas a la colonización por ERV. En conclusión, existe colonización perianal por ERV en los diversos servicios de hospitalización, el gen vanA podría ser transmitido a gérmenes más virulentos y ocasionar la aparición de la bacteria Staphylococcus aureus resistente a vancomicina (VRSA). Es necesario adoptar medidas de control de infecciones para evitar la transmisión de esta bacteria en el ambiente hospitalario.

Molecular Characterization of Extended-Spectrum ß-Lactamase-Producer Klebsiella pneumoniae Isolates Causing Neonatal Sepsis in Peru.

Klebsiella pneumoniae (KP) is the most common cause of neonatal sepsis in the low- and middle-income countries. Our objective was to describe the phenotypic and molecular characteristics of extended-spectrum ß-lactamase (ESBL)-producer KP in neonatal care centers from Peru. We collected 176 non-duplicate consecutive KP isolates from blood isolates of neonates from eight general public hospitals of Lima, Peru. The overall rate of ESBL production was 73.3% (N = 129). The resistance rates were higher among ESBL-producer isolates when compared with the nonproducers: 85.3% versus 12.8% for gentamicin (P < 0.01), 59.7% versus 8.5% for trimethoprim-sulfamethoxazole (P < 0.01), 45.0% versus 8.5% for ciprofloxacin (P < 0.01), and 36.4% versus 12.8% for amikacin (P < 0.01). A total of 359 ß-lactamase-encoding genes were detected among 129 ESBL-producer isolates; 109 isolates (84.5%) carried two or more genes. Among 37 ESBL-producer isolates randomly selected, CTX-M-15 and CTX-M-2 were the most common ESBLs detected. Most of the isolates (92%) belonged to the group KpI. Pulsed-field gel electrophoresis showed that multiple KP clones were circulating among the eight neonatal units included.

Evaluación de métodos fenotípicos para la detección de Staphylococcus aureus resistente a meticilina / Phenotypic methods for detection of methicillin-resistant Staphylococcus aureus

Introducción. Cefoxitina es un potente inductor del gen mecA. Actualmente es recomendado como método de detección presuntiva para la identificación de aislamientos de Staphylococcus aureus resistente a meticilina (SARM). El objetivo del estudio fue comparar la sensibilidad y especificidad de la difusión en disco de cefoxitina (30µg) con la prueba de crecimiento en agar suplementado con oxacilina frente a la detección del gen mecA por PCR. Material y métodos. Trescientos treinta y una cepas de S. aureus aisladas de hemocultivos de pacientes de hospitales de Lima fueron utilizadas en el estudio. Se realizaron las siguientes pruebas a todas las cepas: crecimiento en agar suplementado con 4% de NaCl y 6 mg/L de oxacilina, difusión de cefoxitina (30 μg) y la PCR para amplificar el gen mecA. Resultados. De los 331 aislamientos de S. aureus analizados, en 165 se detectó la presencia del gen mecA, lo que hace una frecuencia de detección de SARM de 50%. Al evaluar la prueba de difusión en disco de cefoxitina se observó una sensibilidad y especificidad, 96,3% y 90,9 %, respectivamente. Conclusión. La prueba de difusión en disco de cefoxitina correlacionó con la detección del gen mecA por PCR. Por lo tanto, la prueba puede ser una alternativa a la PCR para la detección de SARM en aquellos lugares con limitados recursos (AU)

Background. Cefoxitin is a potent inducer of the mecA gene. It is currently as a screening recommended method for presumptive identification of isolates of methicillin resistant Staphylococcus aureus (MRSA). The aim of the study was to compare the sensitivity and specificity of the cefoxitin disc diffusion (30μg) to oxacillin agar screening from detection of the mecA gene by PCR. Methods. Three hundred thirty-one strains of S. aureus isolated from blood cultures of patients from hospitals in Lima were used in the study. The following tests were performed: oxacillin screening agar (plates were inoculated with 4% NaCl and 6 mg/L of oxacillin), cefoxitin disc diffusion test (30 ug) and PCR to amplify the mecA gene. Results. The mecA gene was detected in 165 out of 331 S. aureus isolates. Thus, the frequency of detection of MRSA was 50%. The evaluation of the cefoxitin disc diffusion test showed a 96.3% and 90.9% of sensitivity and specificity, respectively. Conclusion. Cefoxitin disc diffusion test correlated well with detection of the mecA gene by PCR. Therefore, this test can be an alternative to PCR for detection of MRSA in limited resources settings (AU)

Intermediate susceptibility to ciprofloxacin among Salmonella enterica serovar Typhi isolates in Lima, Peru.

Thirty-three Salmonella enterica serovar Typhi blood isolates from Lima, Peru (2008 to 2012), were fully susceptible to trimethoprim-sulfamethoxazole, chloramphenicol, ceftriaxone, and tetracycline; 8/33 (24.2%) showed intermediate susceptibility to ciprofloxacin carrying mutations in the quinolone resistance-determining region of the gyrA gene (Ser83-Phe and Asp87-Asn) and in the gyrB gene (Ser464-Phe).

Enterobacterias productoras de beta-lactamasas de espectro extendido: Situación en América Latina y en el Perú / Extended-spectrum beta lactamasa-producing Enterobacteriaceae: The current situation in Latin America and Peru

La enterobacterias entre ellas la E. coli y Klebsiella vienen mostrando un aumento a la resistencia contra cefalosporinas en el mundo. En el Perú existen escasos estudios sobre este problema. El presente artículo pretende realizar una revisión basada en la evidencia científica sobre este preocupante tema.

Enterobacteriaceae, particularly E. coli and Klebsiella spp. show an increasing resistance to cephalosporins all over the world. There very few studies in Peru about this situation. This paper tries to perform a scientific evidence based review about this increasingly serious problem.