Acinetobacter baumannii analysis by core genome multi-locus sequence typing in two hospitals in Bolivia: endemicity of international clone 7 isolates (CC25).

In total, 95 Acinetobacter baumannii isolates recovered from patients from two hospitals in Cochabamba, Bolivia were studied. The presence of class D and B ß-lactamases was investigated using polymerase chain reaction, and antimicrobial susceptibility testing was performed by agar dilution and broth microdilution. The resistance rate to carbapenems was 53.7%. All carbapenem-resistant A. baumannii (CRAb, n=51) and four carbapenem-susceptible isolates were further analysed by whole-genome sequencing. The resulting genome assemblies were used to identify the acquired resistome, and core genome multi-locus sequence typing (cgMLST) was used to determine their molecular epidemiology. All but one of the CRAb isolates (n=50) belonged to international clone (IC) 7 and they clustered into five sequence types; on cgMLST, they were found to be separated by ≥40 alleles. All CRAb isolates carried blaOXA-23 on transposon Tn2008. Metallo-ß-lactamases were not detected. These data show that dissemination of several IC7 A. baumannii clones harbouring the carbapenem resistance determinant blaOXA-23 is occurring in these two hospitals in Cochambamba.

Identification of Acinetobacter seifertii isolated from Bolivian hospitals.

Acinetobacter seifertii is a recently described species that belongs to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. It has been recovered from clinical samples and is sometimes associated with antimicrobial resistance determinants. We present here the case of three A. seifertii clinical isolates which were initially identified as Acinetobacter sp. by phenotypic methods but no identification at the species level was achieved using semi-automated identification methods. The isolates were further analysed by whole genome sequencing and identified as A. seifertii. Due to the fact that A. seifertii has been isolated from serious infections such as respiratory tract and bloodstream infections, we emphasize the importance of correctly identifying isolates of the genus Acinetobacter at the species level to gain a deeper knowledge of their prevalence and clinical impact.

High Prevalence of Extensively Drug-resistant Acinetobacter baumannii at a Children Hospital in Bolivia.

Acinetobacter baumannii causes serious hospital-acquired infections and has been positioned as a priority organism by the World Health Organization. This study includes 36 A. baumannii isolates from a children hospital recovered between March 2014 and May 2015 in Cochabamba. The majority of the isolates were recovered from blood cultures (n = 10, 31.3%) and respiratory samples (n = 11, 34.4%); 53% of the patients were younger than 1 month old. Most of these isolates (n = 30, 80.6%) were extremely drug resistant and 8.3% were multidrug resistant. The circulation of 2 predominant clones including 25 isolates was determined by pulsed-field gel electrophoresis; 9 of the isolates were considered sporadic strains. The isolates grouped in the predominant clones and 5 of the unrelated sporadic strains were single-locus variant or double locus variant of clonal complex (CC110), belonging to international clone 7; the rest of the isolates were single-locus variant or double locus variant of another clonal complex. All the carbapenem-resistant isolates (88.9%) carried the blaOXA-23-like in a similar structure to Tn2008 located on the chromosome, and the aac(3)-IIa gene was present in all the aminoglycoside-resistant isolates (86.1%). Strong biofilm producers were found among these isolates, being the strongest ones those recovered from the hospital environment, catheter, blood and cerebrospinal fluid (CSF) all of them belonged to the unrelated sporadic strains. The present study demonstrated the predominance and spread of closely related extremely drug-resistant A. baumannii isolates, what confers increasing risk to children and is of major concern because of the kind of infections and the lack of therapeutic alternatives to treat them.

Emergence and clonal dissemination of carbapenem-hydrolysing OXA-58-producing Acinetobacter baumannii isolates in Bolivia.

Acinetobacter baumannii is an emerging multidrug-resistant pathogen and very little information is available regarding its imipenem resistance in Latin American countries such as Bolivia. This study investigated the antimicrobial resistance profile of 46 clinical strains from different hospitals in Cochabamba, Bolivia, from March 2008 to July 2009, and the presence of carbapenemases as a mechanism of resistance to imipenem. Isolates were obtained from 46 patients (one isolate per patient; 30 males,16 females) with an age range of 1 day to 84 years, and were collected from different sample types, the majority from respiratory tract infections (17) and wounds (13). Resistance to imipenem was detected in 15 isolates collected from different hospitals of the city. These isolates grouped into the same genotype, named A, and were resistant to all antibiotics tested including imipenem, with susceptibility only to colistin. Experiments to detect carbapenemases revealed the presence of the OXA-58 carbapenemase. Further analysis revealed the location of the bla(OXA-58) gene on a 40 kb plasmid. To our knowledge, this is the first report of carbapenem resistance in A. baumannii isolates from Bolivia that is conferred by the OXA-58 carbapenemase. The presence of this gene in a multidrug-resistant clone and its location within a plasmid is of great concern with regard to the spread of carbapenem-resistant A. baumannii in the hospital environment in Bolivia.

PRESENCIA DE INTEGRONES Y SU RELACIÓN CON LA RESISTENCIA A ANTIMICROBIANOS EN CEPAS DE Pseudomonas aeruginosa / PRESENCE OF INTEGRONS AND THEIR RELATIONSHIP WITH ANTIMICROBIAL RESISTANCE IN Pseudomonas aeruginosa STRAINS

Debido a que en nuestro medio existe una carencia de datos estadísticos con respecto a la incidencia de infecciones producidas por P. aeruginosa en la población y la resistencia que presenta frente a una variedad de antimicrobianos, el presente estudio tiene como propósito fundamental aportar información y datos sobre la distribución y frecuencia (previa estandarización de la técnica para la detección) de los integrones clase 1 y 2 y su relación con la multirresistencia a antimicrobianos. Para este fin, se obtuvieron muestras de P. aeruginosa de diferentes laboratorios y hospitales del Departamento, a las que se les realizó la prueba de susceptibilidad antimicrobiana, crecimiento de las bacterias a presión selectiva, extracción de ADN y por último detección de integrones clase 1 y 2 con partidores específicos. De 41 muestras obtenidas de P. aeruginosa. se detectó usando PCR, la presencia de integrones clase 1 y clase 2, identificándose éstos en el 58.5 % de las cepas. El 29.27 % de los aislados, llevaba integrones clase 1, el 12,20 % integrones clase 2 y el 17.07 % llevaba ambas clases de integrones. La asociación entre integrones clase 1 y la resistencia múltiple a antimicrobianos fue estadísticamente significativa (chi-cuadrado 0.0033), demostrando la existencia de una fuerte correlación, caso contrario a lo que ocurrió con la asociación entre integrones clase 2 (chi-cuadrado 0.8528). La autenticidad de los productos obtenidos de la PCR, se confirmaron realizando ensayos de restricción con la enzima SphI y la enzima HaeIII. Este es el primer reporte que muestra la prevalencia de integrones clase 1 y la relación con la multirresistencia en aislados de P. aeruginosa en Cochabamba, Bolivia.

Due to the fact that in our environment there is an absence of statistical data related to the incidence of infections produced by P. aeruginosa in our population and the resistance that it presents with respect to a variety of antimicrobial agents, this study aims basically at providing information and data about distribution and frequency (after having standardized the detection techniques) of the integrons classes 1 and 2, and their relationship with their multi resistance to antimicrobial agents. For this purpase, samples of P. aeruginosa were obtained from different laboratories and hospitals in the State of Cochabamba, which were tested for antimicrobial sensibility, as well as for growth of bacteria under selective pressure, DNA extraction and finally detection of integrons class 1 and 2 with specific primers. Using PCR, integrons class 1 and 2 were detected in 41 samples of P. aeroginosa, identifying these ones in 58.5% of the strains: 29.7% of those isolated, carried integrons class 1, 12.2% had integrons class 2, and 17.07% had integrons of both classes. The association between class 1 integrons and multiple resistance to antimicrobial agents was statistically significant (chi square = 0.0033) thus showing a strong correlation, as opposed to what happened with the association among class 2 integrons (chi square = 0.8528) The authenticity of the products obtained from the PCR was confirmed through restriction tests made with SphI and HaeIII enzymes. This is the first report that shows prevalence of class 1 integrons and the relation with multi resistance aisolated strains of P. aeruginosa in Cochabamba, Bolivia.

Congenital Chagas disease in Bolivia is not associated with DNA polymorphism of Trypanosoma cruzi.

This study aims to typify the Trypanosoma cruzi (sub)lineage(s) in umbilical cord blood of congenitally infected Bolivian newborns, using PCR amplifications of "Region Markers", mini-exon or kDNA fragments followed by hybridization or sequencing. New probes were also designed to distinguish three variants within the TcIId sublineage. The IIb, IId, or IIe T. cruzi sublineages, as well as different variants of the IId sublineage, were detected in infected neonates, whereas mixed infections were not found. The frequencies of the IId sublineage were similar in neonates (95.1%) and adults of the same area (94.1%). The IId-infected newborns displayed either asymptomatic, or severe and fatal clinical forms of congenital Chagas disease, as well as low or high parasitemia. Altogether these data show that T. cruzi DNA polymorphism, based on the presently available markers, is not associated with the occurrence of congenital infection or the development of severe clinical forms of congenital Chagas disease.