Single-nucleotide polymorphisms in ialB, gltA and rpoB genes of Bartonella bacilliformis isolated from patients in endemic Peruvian regions.

Bartonella bacilliformis is a Gram-negative, aerobic bacterium and the known causal agent of Carrion's disease, still considered a neglected disease. There is limited information about the nucleotide sequences of this bacterium in international databases, and few studies have addressed the genetic diversity of B. bacilliformis. We analyzed a total of 20 isolates of B. bacilliformis from the Peruvian regions of Ancash and Cajamarca. Three genes (ialB, gltA, and rpoB) were sequenced in each isolate and nucleotide sequences retrieved from GenBank (16 B. bacilliformis genomes) were also included in the study. All this information was merged in order to obtain clearer evidence of the phylogenetic relationships of B. bacilliformis. In the phylogenetic analysis conducted with the concatenated markers, four isolates (B.b-1, B. b-3, B. b- 7, B.b-8) from the Ancash region were observed to form a subgroup different from B. bacilliformis type strain KC583, showing dissimilarity levels of 5.96% (ialB), 3.69% (gltA) and 3.04% (rpoB). Our results suggest that B. bacilliformis consists of two different subgroups. Future investigations are needed to establish the taxonomic status of these subgroups.

In-silico identification of linear B-cell epitopes in specific proteins of Bartonella bacilliformis for the serological diagnosis of Carrion's disease.

Carrion´s disease is caused by Bartonella bacilliformis, it is a Gram-negative pleomorphic bacterium. B. bacilliformis is transmitted by Lutzomyia verrucarum in endemic areas of the Peruvian Inter-Andean valleys. Additionally, the pathogenicity of B. bacilliformis involves an initial infection of erythrocytes and the further infection of endothelial cells, which mainly affects children and expectant women from extreme poverty rural areas. Therefore, the implementation of serological diagnostic methods and the development of candidate vaccines for the control of CD could be facilitated by the prediction of linear b-cell epitopes in specific proteins of B. bacilliformis by bioinformatics analysis. In this study, We used an in-silico analysis employing six web servers for the identification of epitopes in proteins of B. bacilliformis. The selection of B. bacilliformis-specific proteins and their analysis to identify epitopes allowed the selection of seven protein candidates that are expected to have high antigenic activity.

Molecular Characterization of Fluoroquinolone-Resistant Bartonella bacilliformis.

The presence of amino acid changes in GyrA, GyrB, ParC, ParE, and in a proposed chromosomal chloramphenicol acetyl transferase (CAT), as well as mutations at 23S rRNA, were established by PCR and sequencing in 38 B. bacilliformis clinical isolates from four different areas in Peru. Eighteen out of 24 (75%) isolates showing ciprofloxacin resistance for both disk-diffusion and e-test presented amino acid substitutions in GyrA (G89C, six isolates, A91V, 1 isolate) GyrB (S474F, 10 isolates) or both (GyrA D95N and GyrB S474F, one isolate). Two out of 14 susceptible isolates presented amino acid substitutions at GyrB (S474F) or a double substitution GyrA D95N and GyrB S474F. Of note, ciprofloxacin-resistant isolates were recovered in the four areas studied. No amino acid change was observed at ParC or ParE. Only one isolate showed chloramphenicol resistance, but no alteration was present in either 23S rRNA or CAT. B. bacilliformis resistant to quinolones are extended throughout Peru, with amino acid substitutions at GyrA or GyrB as the main, albeit not exclusive, cause. B. bacilliformis seems to have an apparent facility to develop mutations on GyrB outside the classical positions 91, 95 of GyrA and 85, 88 of ParC.

Resistencia antimicrobiana de cepas de Bartonella bacilliformis procedentes de regiones endémicas de la enfermedad de Carrión en el Perú / Antimicrobial resistance of Bartonella bacilliformis strains from regions endemic to bartonellosis in Peru

Evaluar la susceptibilidad antimicrobiana in vitro a cloranfenicol (CHL) y ciprofloxacino (CIP) de cepas de Bartonella bacilliformis procedentes de áreas endémicas de la enfermedad de Carrión (EC) en el Perú, mediante tres métodos de laboratorio. Materiales y métodos. Se evaluó la susceptibilidad antimicrobiana a CHL y CIP de 100 cepas de Bartonella bacilliformis, los aislamientos procedieron de pacientes de los departamentos de Ancash, Cusco, Cajamarca, Lima y La Libertad; las cepas se evaluaron mediante: disco difusión, E-Test y dilución en agar. Resultados. El 26% de las cepas de Bartonella bacilliformis evaluadas, presentaron resistencia a CIP y 1% a CHL. Se obtuvieron patrones similares de sensibilidad/resistencia antimicrobiana en los tres métodos utilizados. Conclusiones. Las cepas de Bartonella bacilliformis circulantes en el Perú, presentan elevados niveles de resistencia in vitro a CIP, por lo que se recomienda ampliar la investigación sobre la utilización del fármaco en los esquemas de tratamiento de la EC. Los métodos de E-test y disco difusión resultaron más convenientes para la evaluación de la susceptibilidad antimicrobiana in vitro del microorganismo...

To evaluate in vitro antimicrobial susceptibility to chloramphenicol (CHL) and ciprofloxacin (CIP) in strains of Bartonella bacilliformis from areas that are endemic to Bartonellosis in Peru, through three laboratory methods. Materials and methods. Antimicrobial susceptibility to CHL and CIP from 100 strains of Bartonella bacilliformis isolated in patients from the regions of Ancash, Cusco, Cajamarca, Lima and La Libertad were evaluated. Strains were evaluated by: disk diffusion, E-test and agar dilution. Results. 26% of the strains of Bartonella bacilliformis evaluated were resistant to CIP and 1% to CHL. Similar patterns of antimicrobial sensitivity / resistance were obtained in all three methods. Conclusions. Bartonella bacilliformis strains circulating in Peru have high levels of in vitro resistance to CIP, so it is advisable to expand research on the use of drug treatment regimens of the Bartonellosis. The methods of E-test and disk diffusion were the most suitable for assessment in vitro of antimicrobial susceptibility of the microorganism...

[Antimicrobial resistance of Bartonella bacilliformis strains from regions endemic to bartonellosis in Peru]. / Resistencia antimicrobiana de cepas de Bartonella bacilliformis procedentes de regiones endémicas de la Enfermedad de Carrión en EL Perú.

OBJECTIVES: To evaluate in vitro antimicrobial susceptibility to chloramphenicol (CHL) and ciprofloxacin (CIP) in strains of Bartonella bacilliformis from areas that are endemic to Bartonellosis in Peru, through three laboratory methods. MATERIALS AND METHODS: Antimicrobial susceptibility to CHL and CIP from 100 strains of Bartonella bacilliformis isolated in patients from the regions of Ancash, Cusco, Cajamarca, Lima and La Libertad were evaluated. Strains were evaluated by: disk diffusion, E-test and agar dilution. RESULTS: 26% of the strains of Bartonella bacilliformis evaluated were resistant to CIP and 1% to CHL. Similar patterns of antimicrobial sensitivity / resistance were obtained in all three methods. CONCLUSIONS: Bartonella bacilliformis strains circulating in Peru have high levels of in vitro resistance to CIP, so it is advisable to expand research on the use of drug treatment regimens of the Bartonellosis. The methods of E-test and disk diffusion were the most suitable for assessment in vitro of antimicrobial susceptibility of the microorganism.