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Urinary tract infections (UTIs) are a common human infection. Antibiotic resistance in extended-spectrum β-lactamase (ESBL)-producing uropathogenic E. coli (UPEC) is a major therapeutic challenge due to limited treatment alternatives. The aim was to characterize the antimicrobial resistance (AMR) and dynamics of ESBL-producing UPEC isolates from UTI cases seen at a local hospital in Cusco, Peru. Ninety-nine isolates from respective patients were characterized against 18 different antibiotics. Latent class analysis (LCA) was used to evaluate the dynamics across the study time according to resistance patterns. The median age of patients was 51 years old, and nearly half were women. ESBL-producing UPEC isolates were slightly more frequent in outpatient services than emergency rooms, and there were higher resistance rates in males compared to females. Half of the ESBL producers were resistant to aminoglycosides and nitrofurantoin. Cefoxitin and fosfomycin resistance was 29.3% and 14.1%, respectively. Resistance to carbapenems was not observed. All isolates were multidrug-resistant bacteria, and 16.2% (16/99) were also classified as extensively drug-resistant bacteria. The resistance patterns varied across the study time and differed regarding sex and healthcare service. The study revealed high levels of AMR to commonly used antimicrobials and a dynamic circulation of ESBL-producing UPEC isolates with varying resistance patterns.

This study aimed to determine the frequency of colistin resistance in Pseudomonas aeruginosa isolates obtained from three healthcare facilities in Lima and cryopreserved at the Laboratorio de Resistencia Antimicrobianos e Inmunopatologia of the Universidad Peruana Cayetano Heredia (UPCH). The colistin broth disk elution method was used for the phenotypic identification of colistin resistance. We detected the expression of the mcr-1 gene by using the phenotypic diffusion method with combined colistin and ethylenediaminetetraacetic acid (EDTA) disks; and polymerase chain reaction (PCR) was used for molecular identification of the gene. Of the 97 isolates, 7 (7.2%) were resistant to colistin; however, none carried the mcr-1 gene. This is the first report from Peru on clinical isolates of colistin-resistant Pseudomonas aeruginosa, which suggests the need for implementation of appropriate methodologies for the epidemiological surveillance of colistin-resistant pathogens El objetivo del estudio fue determinar la frecuencia de resistencia a la colistina en Pseudomonas aeruginosa provenientes de tres establecimientos de salud de Lima, criopreservados en el banco de cepas del Laboratorio de Resistencia a Antimicrobianos e Inmunopatología de la Universidad Peruana Cayetano Heredia (UPCH). El método de elución de discos de colistina en caldo fue empleado para la identificación fenotípica de la resistencia a la colistina; la detección de la expresión del gen mcr-1 se realizó mediante el método fenotípico de difusión de discos combinados de colistina y ácido etilendiaminotetraacético (EDTA) y la reacción en cadena de la polimerasa (PCR) para la identificación molecular del gen. De los 97 aislados estudiados, 7 (7,2%) fueron resistentes a la colistina y ninguno fue portador del gen mcr-1. Este estudio constituye el primer reporte en el Perú de aislados clínicos de Pseudomonas aeruginosa resistentes a la colistina, lo que implica la necesidad de implementar metodologías apropiadas para la vigilancia epidemiológica de patógenos resistentes a la colistina

Providencia stuartii is an opportunistic pathogen of the Enterobacteriales order. Here, we report the 4,594,658-bp draft genome sequence of a New Delhi metallo-β-lactamase (NDM-1)-producing Providencia stuartii strain that was isolated from an emergency patient in a private clinic in Lima, Peru.

Introduction: The salmonelloses are among the commonest, most widespread human zoonotic infections. They have generated international networks to attempt their control, since they cause a spectrum of ailments, ranging from inapparent carrier states to full-blown, severe, sometimes deadly diarrheal and systemic disease. Rapid diagnosis is needed for a number of reasons. The aim of this study was to standardize and validate a phage amplification test for the identification of salmonellosis to be applied to infections of Cavia porcellus. Methods: Native bacteriophages were isolated from infected cavies and environmental residues from commercial cavy-breeding facilities. Salmonella enterica serovar Typhimurium ATCC 14028 was used to detect, isolate and propagate the bacteriophages, and to standardize a phage amplification assay to detect S. Typhimurium from rectal swabs of cavies. The phage amplification assay was tested using 2 antiviral agents, MgSO4.7H2O (MAS) and pomegranate rind extract (PRE) plus ferrous sulfate (PRE-FeSO4). Results: The final assay format chosen used PRE-FeSO4 and allowed detection of S. Typhimurium in 90 min from culture, 5 h from clinical samples, with a limit of detection at 10(3) pfu; sensitivity was 98.2%, specificity 98%, negative predictive value (NPV) 96.1%, and positive predictive value (PPV) 99.1%. Conclusion: Bacteriophage amplification is therefore an appropriate, fast procedure for detection of this pathogen in clinical samples.

Introduction: Cell phones are susceptible to bacterial contamination. The aim of this study was to characterize the bacterial isolates and to explore their dispersion in five Intensive Care Units (ICUs) over the time. Methods: We performed a secondary analysis of non-fermenting Gram-negative bacteria and Gram-positive cocci isolated from a 5-month observational cohort study developed among health care workers' cell phones in five ICUs. Cell phones were sampled using a swab every 15 days. Antimicrobial resistance was determined by the minimum inhibitory concentration method. We constructed resistance phenotypes to group the isolates according to species and antimicrobial resistance pattern to explore dispersion through time. Results: A total of 35 P. aeruginosa, 16 Acinetobacter spp., 30 S. aureus and 26 Enterococcus spp. were isolated from 491 phone samples. Multidrug resistance was 2.9% for P. aeruginosa, 31.3% for Acinetobacter spp., 46.7% for S. aureus and 80.8% for Enterococcus spp. The resistance to methicillin in S. aureus and to vancomycin in Enterococcus spp. was 26.7% and 42.3%, respectively. We did not observe distribution patterns or clusters over the time for P. aeruginosa, Acinetobacter spp. and Enterococcus spp. isolates. All the S. aureus isolates grouped into eight phenotypes. Interestingly, we observed S. aureus isolates with the same phenotype in consecutive and separate sampling dates in the same cell phone. Conclusion: Cell phones are contaminated with highly harmful bacteria and potentially can maintain them for prolonged periods of time. These devices could be considered as a potential source of nosocomial infections in ICUs.

The emergence and dissemination of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) is a worrisome public health issue compromising the treatment and outcome of infections caused by this pathogen. We performed a detailed virulome and resistome analysis of representative KPC- and/or CTX-M-producing K. pneumoniae belonging to clonal group (CG) 258 (sequence types ST11, ST258, ST340, ST437), circulating in Argentina, Brazil, Chile, Colombia and Peru; with further evaluation of the virulence behavior using the Galleria mellonella infection model. Genomic analysis of K. pneumoniae strains recovered from the human-animal-environment interface revealed a wide resistome characterized by the presence of genes and mutations conferring resistance to human and veterinary antibiotics, quaternary ammonium compounds (QACs) and heavy metals. Plasmid Inc typing revealed the presence of a wide diversity of replicon types with IncF, IncN, IncR and Col-like being frequently detected. Moreover, KPC-2-producing K. pneumoniae belonging to ST11 (KL-64 andKL-105) and ST340 (KL-15) carried multiple variants of distinct yersiniabactin siderophore (ybt) and/or genotoxic colibactin (clb) genes. In this regard, ICEKp3, ICEKp4 and ICEKp12 were identified in strains belonging to ST11 and ST340, recovered from Argentina, Brazil, Chile and Colombia; whereas ybt 17 and a novel ybt sequence type (YbST346) were identified together with clb in ICEKp10 structures from ST11 and ST258, from Brazil and Colombia, respectively. K. pneumoniae ST11 (ICEKp10/YbST346 and ICEKp4/ybt 10) strains killed 100% of wax moth larvae, in a similar way to hypervirulent K1/ST23 strain (ybt- and clb-negative) carrying the pLVPK-like plasmid, indicating enhanced virulence. In summary, our results indicate that yersiniabactin, colibactin and an expanded resistome have contributed to enhanced virulence and persistence of KPC-2-producing K. pneumoniae CG258 in South America. Therefore, active surveillance of hospital-associated lineages of K. pneumoniae should not only focus on clonal origin and antimicrobial resistance, but also on the virulence factors ybt and clb.

We present here the draft genome sequence of the first New Delhi metallo-β-lactamase (NDM-1)-producing Escherichia coli strain, belonging to sequence type 155 (ST155), isolated in Peru. Assembly of this draft genome resulted in 5,061,184 bp, revealing a clinically significant resistome for β-lactams, aminoglycosides, tetracyclines, phenicols, sulfonamides, trimethoprim, and fluoroquinolones.

Objectives The aim of this study was to characterise a KPC-carrying Klebsiella pneumoniae isolate from a Peruvian hospital setting. Methods The identity of the isolate was confirmed by amplification and sequencing of the 16S rRNA gene, and the antibiotic resistance profile was determined by disk diffusion and automated methods The sequence type (ST) and phylogenetic group were established by PCR. The presence of different β-lactamase genes was determined, including blaMBL, blaKPC, blaCTX-M, blaSHV, blaOXA-1-like, blaOXA-2-like, blaOXA-5-like, blaOXA-48-like and blaTEM and up to six different plasmid-encoded AmpC genes as well as class 1 integrons. The conjugability of β-lactam resistance was assessed by conjugation. Results The isolate was confirmed to be K. pneumoniae classified as belonging to the KpI phylogenetic group within ST340, which belongs to the high-risk clonal complex 258 (CC258). The isolate was resistant to all β-lactam agents tested, with only the presence of a non-conjugative blaKPC-2 gene being detected and carried in a non-classical genetic structure. Conclusions This is the first description of a member of CC258 and of a blaKPC-2 gene in Peru. Intensive surveillance is needed to determine the relevance of both in this area.

Objetivos: Determinar las características fenotípicas y genotípicas de las β-lactamasas de espectro extendido (BLEE) en E. coli aislados de cultivos de orina de pacientes de la comunidad en un laboratorio privado de la ciudad de Lima, Perú. Material y métodos: Se evaluaron 53 aislamientos de E. coli por dos métodos fenotípicos: Jarlier y CLSI, el perfil de susceptibilidad se realizó mediante disco difusión y la caracterización genotípica mediante PCR para los genes blaCTX-M, blaTEM y blaSHV. Resultados: Los 53 aislamientos productores de BLEE representaron el 16,30% del total de aislados de E. coli, afectando principalmente a mujeres mayores de 65 años. El perfil de susceptibilidad evidenció alta resistencia a AMP,CEF,CRO(100%), LEV(87%), NOR(92%), CIP y NAL(94%), CXM y CTX(96%),SXT(70%), ATM(75%) y TOB (85%); asimismo elevada sensibilidad a NIT e IPM(100%), AMK(91%) y FOF(73,6%). El tipo de gen bla más frecuente fue blaCTX-M (55%), seguido por la coexistencia blaCTX-M+TEM (24%), blaTEM (13%) y blaSHV (6%). Conclusiones: La frecuencia de E. coli productores de BLEE fue de 16,3%; siendo el gen tipo blaCTX-M el más frecuente, información valiosa para orientar la terapia antimicrobiana empírica. Objective: To determine the phenotypic and genotypic features of extended spectrum beta-lactamase (ESBL) producing strains of Escherichia coli isolated from urine samples of patients attending outpatient services in a private laboratory in Lima, Peru. Methods: 53 E. coli isolates were evaluated using two phenotypic methods: Jarlier and CLSI, the susceptibility profile was performed using the disk diffusion method and the genotypic features were analyzed using PCR for detecting blaCTX-M, blaTEM y blaSHV genes. Results: The 53 ESBL producing strains of E. coli accounted for 16,30% of all E. coli isolates affecting mostly women older than 65 years. High resistant profile to AMP, CEF, CRO (100%), LEV (87%), NOR (92%), CIP, NAL (94%), CXM, CTX (96%), SXT (70%), ATM (75%) and TOB (85%) was observed. High susceptibility to NIT, IPM (100%), AMK (91%) and FOF (73.6%) was observed. The most frequent bla gen was blaCTX-M (55%), followed by blaCTX-M+TEM (24%), blaTEM (13%) and blaSHV (6%). Conclusions: The rate of ESBL producing strains of E. coli was 16.3% and the blaCTX-M gen was the most common gene type. These results provide valuable information for starting empiric antibiotic therapy in this setting.

Objetivos: Evaluar la actividad de los bacteriófagos frente a infecciones localizadas y sistémicas producidas por Staphylococcus aureus resistente a meticilina (MRSA) Materiales y métodos. Se realizó un estudio de tipo experimental en 45 ratones de la cepa Balb/c divididos en nueve grupos de cinco individuos. Se aislaron diez bacteriófagos nativos a partir de muestras clínicas y efluentes hospitalarios, se evaluó su capacidad lítica y su espectro de actividad, en base a lo cual se seleccionaron seis fagos para los ensayos de fagoterapia. Adicionalmente, se empleó un bacteriófago de origen comercial. La fagoterapia fue evaluada mediante profilaxis y terapia de infecciones localizadas y sistémicas causadas por la inoculación de MRSA por vía subcutánea y endovenosa respectivamente. Se probó la efectividad de tres esquemas terapéuticos: monoterapia, cóctel de fagos en múltiples dosis y de cóctel de fagos en una sola dosis. También se comparó la actividad terapéutica de los fagos frente a vancomicina y clindamicina. Resultados. El cóctel de fagos y la terapia a diversas dosis fueron efectivos para prevenir y controlar infecciones localizadas por MRSA, su actividad fue similar a la de vancomicina y clindamicina. La dosis única del cóctel de fagos no logró controlar la infección localizada; asimismo, la fagoterapia no resultó efectiva en infecciones sistémicas. Conclusiones. La fagoterapia se proyecta como una alternativa viable frente a infecciones causadas por MRSA. Se requieren estudios que evalúen aspectos relacionados con la inocuidad de los fagos frente al paciente Objectives: To assess the bacteriophage activity in localized and systemic infections caused by Staphylococcus aureus resistant to methicilin (MRSA). Materials and methods. An experimental study was performed in 45 mice of the Balb/c strain divided in nine groups of five individuals. Ten naive bacteriophages were isolated through clinical samples and hospital effluents. Lytic capacity and spectrum activity was evaluated on the basis of which six phages were selected for phagotherapy trials. Additionally, a commercial bacteriophage was used. The phagotherapy was evaluated through prophylaxis, and therapy of localized and systemic infections caused by MRSA by subcutaneous and intravenous inoculation, respectively. The effectiveness of three therapeutic schemes was tested: monotherapy, phage cocktail in multiple doses and phage cocktail in a single dose. The therapeutic activity of the phages was also compared with vancomycin and clindamycin. Results. The phage cocktail and the diverse dose therapy were effective in preventing and controlling MRSA localized infections; its activity was similar to the vancomycin and clindamycin activity. The single dose phage cocktail failed to control localized infection and phagotherapy was not effective in systemic infections. Conclusions. Phagotherapy could be a viable alternative for infections caused by MRSA. Further studies that assess related aspects to phages and patient safety are required

Objetivo: Determinar la frecuencia de vaginosis bacteriana (VB) en trabajadoras sexuales (TS) que acuden a un centro especializado de referencias de enfermedades de transmisión sexual y SIDA (CERETSS) en Lima, Perú; y su asociación con características gineco-obstétricas. Material y Métodos: Estudio transversal realizado en 322 TS que acudieron a la consulta médica en un CERETSS de diciembre del 2008 a enero del 2009. Se obtuvieron muestras de flujo vaginal y se emplearon los métodos de Amsel y Nugent para el diagnóstico de VB. Resultados: La frecuencia de VB fue 26,1%. La VB estuvo asociada con el conocimiento de VB, antecedentes de VB y Enfermedades de Transmisión Sexual (ETS), número de partos, número de abortos y número de parejas sexuales por día. Conclusiones: La frecuencia de VB en esta población es elevada, siendo necesaria la implementación de medidas que conduzcan a su control. (Rev Med Hered 2010;21:32-38). Objective: To determine the frequency of bacterial vaginosis (BV) in female sex workers (SW) attending a specialized reference centers for Sexually Transmitted Diseases and AIDS (CERETSS) in Lima - Peru, and its association with gynecological and obstetric characteristics. Material and Methods: We conducted a cross-sectional study between December 2008 to January 2009. We studied 322 SW who were seen as outpatients at a CERETSS. Vaginal secretion samples were obtained and Amsel and Nugent methods were used for the diagnosis of BV. Results: The frequency of BV was 26.1%. BV was associated with awareness of VB, VB background and Sexually Transmitted Diseases (STD), parity, number of abortions and number of sexual partners per day. Conclusions: The frequency of BV in this population is high, therefore it is necessary to implement measures to prevent and control them.(Rev Med Hered 2010;21:32-38).

Staphylococcus aureus es un importante patógeno involucrado en una serie de infecciones e intoxicaciones, presenta múltiples factores de virulencia y su impacto se incrementa por su notable resistencia a los antimicrobianos. Objetivo: Determinar la frecuencia de Staphylococcus aureus meticilino resistente adquiridos en la comunidad, en hospitales de Lima- Perú. Material y métodos: Se realizó un estudio descriptivo multicéntrico. La resistencia a meticilina se determinó por el método Oxacillin Agar Screen. El origen de la cepa fue determinado mediante los criterios de los CDC; la Leucocidina de Panton Valentine fue identificada por métodos moleculares. Resultados: Se aislaron 276 cepas de Staphylococcus aureus, 160 fueron resistentes a meticilina (58%), 9 de ellas fueron identificadas como adquiridas en la comunidad (5,6%). La PVL fue identificada en 25 cepas (9,1%), 14 fueron MSSA y 11 MRSA, de éstas últimas solo 4 fueron MRSAcom, 7 fueron MRSAhosp (p

Objetivo. Comparar la eficacia de cuatro métodos fenotípicos para la identificación de cepas productoras de β-lactamasas de espectro extendido aisladas de urocultivos. Materiales y métodos. Estudio comparativo de corte transversal. Se analizó 147 cepas aisladas de urocultivos positivos para Escherichia coli, Klebsiella pneumoniae y Proteus mirabilis entre los meses de enero y febrero de 2009 en el Instituto Nacional de Salud del Niño, las cuales fueron sometidas a una prueba de tamizaje, en aquellas que resultaron positivas se realizó pruebas confirmatorias mediante los cuatro métodos fenotípicos evaluados. Resultados. De las 147 cepas, 43 (29,3%) resultaron sospechosas en las pruebas de tamizaje. Con el método descrito por Clinical and Laboratory Standards Institute (CLSI) usado como "patrón de oro" para el estudio, resultaron 27 positivas (62,8%), resultado similar a lo encontrado con el método de Jarlier. Por otro lado, con los métodos de Hodge y el tridimensional, 23 (53,5%) resultaron positivas. La evaluación de los métodos confirmatorios frente al descrito por CLSI, mostró una sensibilidad y especificidad de 100% para el método de Jarlier; en el caso de los métodos de Hodge y método tridimensional se encontró una sensibilidad y especificidad de 85,2 % y 100%, respectivamente. Conclusiones. Los métodos evaluados mostraron en todos los casos una alta eficacia, sin presentar diferencias significativas, por lo que podrían utilizarse según las facilidades del laboratorio clínico involucrado; sin embargo dada las ventajas no técnicas, como costos, facilidad y factibilidad de su aplicación, se recomienda el empleo del método de Jarlier. Objective. To compare the efficacy of four phenotypic methods for the identification of strains producing extendedspectrum β-lactamases isolated from urine cultures. Materials and methods. Comparative cross-sectional study. 147 strains isolated from positive urine cultures for Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis between January and February 2009 in the National Institute of Health of Children underwent a screening test, those which resulted positive were processed for confirmatory testing through the four phenotypic methods evaluated. Results. Out of the 147 strains, 43 (29.3%) were suspicious in the screening tests. Using the method described by the Clinical and Laboratory Standards Institute (CLSI) as a reference standard for this study, 27 strains (62.8%) were positive, with similar results using Jarlier´s method. On the other hand, using Hodge´s and tridimensional methods 23 (53.5%) of samples were positive. The evaluation of the confirmation methods in comparison to the one described by CLSI, showed a sensitivity and specificity of 100% for Jarlier´s method, on the other hand, for Hodge´s and tridimensional methods we found a sensitivity of 85.2% and 100%, respectively. Conclusions. All the evaluated methods showed a high efficacy, without significant differences, so they could all be used according to the available facilities of each clinical laboratory. Nevertheless, due to its advantages besides the technical aspect, like costs, easiness and feasibility of its application, we recommend the use of Jarlier´s method.

The purpose of this study was to determine the carriage rate, susceptibility pattern, and serotype distribution of Streptococcus pneumoniae in the nasopharynx of children younger than 2 years old in Lima, Peru. A total of 666 children were evaluated during 3 periods, 1997, 2001, and 2003. The overall pneumococcal carrier rate was 41%. Reduced susceptibility to penicillin was found in 5% (4/75) of isolates in 1997, 20% (15/75) in 2001, and 37% (40/109) in 2003. Reduced susceptibility to ceftriaxone was found in 12% of isolates in 2003. Serogroups 6, 19, 23, 15, and 14 accounted for 68% of all the isolates and for 81% of the penicillin-nonsusceptible strains. Only 65% of the isolated strains had serogroups found in the 7-valent conjugate pneumococcal vaccine. This highlights the importance of regional surveillance studies for effective vaccine strategies and treatment protocols.

Objetivos: Determinar la frecuencia de serogrupos y serotipos y el perfil de susceptibilidad antimicrobiana de Shigella sp., aisladas en un instituto pediátrico de Lima, Perú. Material y métodos: Se evaluaron 85 aislamientos de Shigella sp., identificados bioquímicamente y serológicamente a nivel de serogrupo y serotipo por el método de aglutinación en lámina. Los patrones de resistencia antibiótica se determinaron mediante el método de disco difusión en agar. Resultados: De los 85 aislamientos de Shigella sp., 53 (62,3%) correspondieron al serogrupo B (Shigella flexneri), 28 (32,9%) al grupo D (Shigella sonnei) y 4 (4,8%) al grupo C (Shigella boydii), ningún aislamiento correspondió al grupo A (Shigella dysenteriae). Respecto a los serotipos, en el grupo B, fueron 46% 1b, 36% 2a y 18% variante Y; en el grupo C fue C4 y en el grupo D todos fueron Fase I. La evaluación del perfil de susceptibilidad mostró que el 100% de las cepas fueron sensibles a aztreonam, ácido nalidíxico y ciprofloxacina; entre 80 y 90% fueron resistentes a trimetoprim-sulfametoxazol, ampicilina y tetraciclina. Conclusiones: El serogrupo más frecuente fue Shigella flexneri, no se reportó Shigella dysenteriae. Existe elevado nivel de resistencia a Sulfametoxazole/trimetoprim, ampicilina y tetraciclina Objectives: To determine the frequency of serogroups and serotypes and antimicrobial susceptibility profile of Shigella sp., isolated in a pediatric institute from Lima, Peru. Methods: Observational study conducted in 85 isolates of Shigella sp., serologically identified to serogroup and serotype by slide agglutination method. The antibiotic resistance patterns were determined by disk diffusion in agar. Results: 53 (62.3%) were serogroup B (Shigella flexneri), 28 (32.9%) group D (Shigella sonnei) and 4 (4.8%) group C (Shigella boydii) , no bacteria group A (Shigella dysenteriae) was isolated. Respect to serotypes, in group B were 46% 1b, 36% 2a y 18% Y variant; in group C was C4 and in group D all were phase I. Evaluation of susceptibility profile showed that 100% of the strains were susceptible to aztreonam, nalidixic acid and ciprofloxacin; between 80 and 90% were resistant to trimethoprim-sulfamethoxazole, ampicillin and tetracycline. Conclusions: The most common serogroup was Shigella flexneri. Shigella dysenteriae was not reported. There is a high level of resistance sulfamethoxazole / trimethoprim, ampicillin and tetracycline.