Showing papers on "Bartonella bacilliformis published in 2016"

Succinyl-CoA Synthetase: New Antigen Candidate of Bartonella bacilliformis.

Abstract: Background Bartonella bacilliformis is the causative agent of Carrion’s disease, a neglected illness with mortality rates of 40–85% in the absence of treatment. The lack of a diagnostic technique to overcome misdiagnosis and treat asymptomatic carriers is of note. This study aimed to identify new B. bacilliformis antigenic candidates that could lead to a new diagnostic tool able to be implemented in endemic rural areas. Methodology/Principal Findings Blood (n = 198) and serum (n = 177) samples were collected in northern Peru. Clinical data were recorded. Specific 16S rRNA amplification by RT-PCR, IFA and ELISA for IgM/IgG with whole cells as antigens was done. Western blot analysis and N-terminal amino acid sequencing detected seroreactive proteins. ELISAs for IgM/IgG for the antigenic candidates were performed. Of the population 33.3% reported at least one symptom compatible with Carrion’s disease; 25.4% (IFA), 27.1% (ELISA-IgG), 33.9% (ELISA-IgM) and 38.9% (RT-PCR) of samples were positive. Four proteins were considered potential antigenic candidates, including two new antigenic candidates, succinyl-CoA synthetase subunit α (SCS-α) and succinyl-CoA synthetase subunit β (SCS-β). On Western blot both Pap31 and SCS-α interacted with IgM, while GroEL and SCS-β interacted with IgG. The presence of specific antibodies against the antigenic candidates varied from 34.5% (IgG against SCS-α) to 97.2% (IgM against Pap31). Conclusions/Significance RT-PCR and the high levels of positivity for specific ELISAs demonstrate high levels of B. bacilliformis exposure and asymptomatic carriers among inhabitants. The new antigens identified might be used as a new rapid diagnostic tool to diagnose acute Carrion’s disease and identify asymptomatic carriers.

Mutation-Driven Divergence and Convergence Indicate Adaptive Evolution of the Intracellular Human-Restricted Pathogen, Bartonella bacilliformis.

Abstract: Among all species of Bartonella, human-restricted Bartonella bacilliformis is the most virulent but harbors one of the most reduced genomes. Carrion’s disease, the infection caused by B. bacilliformis, has been afflicting poor rural populations for centuries in the high-altitude valleys of the South American Andes, where the pathogen’s distribution is probably restricted by its sand fly vector’s range. Importantly, Carrion’s disease satisfies the criteria set by the World Health Organization for a disease amenable to elimination. However, to date, there are no genome-level studies to identify potential footprints of B. bacilliformis (patho)adaptation. Our comparative genomic approach demonstrates that the evolution of this intracellular pathogen is shaped predominantly via mutation. Analysis of strains having publicly-available genomes shows high mutational divergence of core genes leading to multiple sub-species. We infer that the sub-speciation event might have happened recently where a possible adaptive divergence was accelerated by intermediate emergence of a mutator phenotype. Also, within a sub-species the pathogen shows inter-clonal adaptive evolution evidenced by non-neutral accumulation of convergent amino acid mutations. A total of 67 non-recombinant core genes (over-representing functional categories like DNA repair, glucose metabolic process, ATP-binding and ligase) were identified as candidates evolving via adaptive mutational convergence. Such convergence, both at the level of genes and their encoded functions, indicates evolution of B. bacilliformis clones along common adaptive routes, while there was little diversity within a single clone.

Development and characterisation of highly antibiotic resistant Bartonella bacilliformis mutants

Abstract: The objective was to develop and characterise in vitro Bartonella bacilliformis antibiotic resistant mutants. Three B. bacilliformis strains were plated 35 or 40 times with azithromycin, chloramphenicol, ciprofloxacin or rifampicin discs. Resistance-stability was assessed performing 5 serial passages without antibiotic pressure. MICs were determined with/without Phe-Arg-β-Napthylamide and artesunate. Target alterations were screened in the 23S rRNA, rplD, rplV, gyrA, gyrB, parC, parE and rpoB genes. Chloramphenicol and ciprofloxacin resistance were the most difficult and easiest (>37.3 and 10.6 passages) to be selected, respectively. All mutants but one selected with chloramphenicol achieved high resistance levels. All rifampicin, one azithromycin and one ciprofloxacin mutants did not totally revert when cultured without antibiotic pressure. Azithromycin resistance was related to L4 substitutions Gln-66 → Lys or Gly-70 → Arg; L4 deletion Δ62–65 (Lys-Met-Tyr-Lys) or L22 insertion 83::Val-Ser-Glu-Ala-His-Val-Gly-Lys-Ser; in two chloramphenicol-resistant mutants the 23S rRNA mutation G2372A was detected. GyrA Ala-91 → Val and Asp-95 → Gly and GyrB Glu474 → Lys were detected in ciprofloxacin-resistant mutants. RpoB substitutions Gln-527 → Arg, His-540 → Tyr and Ser-545 → Phe plus Ser-588 → Tyr were detected in rifampicin-resistant mutants. In 5 mutants the effect of efflux pumps on resistance was observed. Antibiotic resistance was mainly related to target mutations and overexpression of efflux pumps, which might underlie microbiological failures during treatments.

Carrion’s Disease: More Than a Sand Fly–Vectored Illness

Abstract: What Is Carrion’s Disease?: The Forgotten Carrion’s disease is a biphasic illness (S1 Fig) caused by an infection of Bartonella bacilliformis, a bacterium that is transmitted through bites of certain phlebotomine sand flies in the Andean valleys of Peru and in some areas of Ecuador and southern Colombia [1,2]. The acute phase, called Oroya fever, is a serious, life-threating illness that mainly affects immunologically naïve populations, such as children. It is also of special concern in pregnant women, because high mortality rates have been described as well as miscarriages, preterm births, and fetal deaths [3]. In this acute phase, the absence or delay of antibiotic treatment may lead to fatal outcomes. In fact, it is considered that, in the pre-antibiotic era, the lethality of this illness ranked between 40% and 88% [1,2]. In the chronic phase, classically considered to occur in previously exposed inhabitants, B. bacilliformis induce endothelial cell proliferation, producing skin lesions called Peruvian warts. In this phase, the lethality is very low [1]. Additionally, the presence of asymptomatic carriers is frequent, although the real numbers remain uncertain because of the difficulty in detecting these subjects (Table 1) [4]. Until now, no reservoir other than humans has ever been described, and, thus, due to the geographically defined area and the lack of animal reservoirs, this disease could be potentially eradicated. The role of undescribedBartonella spp. as a cause of Carrion’s-disease–like symptoms cannot be ruled out. Indeed, other Bartonella spp. have correlated to Carrion’s-disease–like presentations. Thus, Bartonella rochalimae, which is disseminated worldwide [5], was associated with a mild Oroya-fever–like episode in a tourist after a trip to Peru, whereas Bartonella ancashensis has been isolated from Peruvian warts of children living in an endemic Peruvian area [1]. Despite vector transmission being by far the most relevant route of transmission, other possible routes should be highlighted.Due to the nature of the illness, all direct inoculation or contact with infected human blood may result in its acquisition; thus, blood transfusions as well as accidental contact with infected blood in laboratories or during medical practices need to be considered. Additionally, vertical transmission and contact with other human fluids should also be considered (Fig 1).

Multi-Locus Sequence Typing of Bartonella bacilliformis DNA Performed Directly from Blood of Patients with Oroya’s Fever During a Peruvian Outbreak

Abstract: Background Bartonella bacilliformis is the etiological agent of Carrion’s disease, a neglected tropical poverty-linked illness. This infection is endemic of Andean regions and it is estimated that approximately 1.7 million of South Americans are at risk. This bacterium is a fastidious slow growing microorganism, which is difficult and cumbersome to isolate from clinical sources, thereby hindering the availability of phylogenetic relationship of clinical samples. The aim of this study was to perform Multi Locus Sequence Typing of B. bacilliformis directly in blood from patients diagnosed with Oroya fever during an outbreak in Northern Peru. Methodology/Principal Findings DNA extracted among blood samples from patients diagnosed with Oroya’s fever were analyzed with MLST, with the amplification of 7 genetic loci (ftsZ, flaA, ribC, rnpB, rpoB, bvrR and groEL) and a phylogenetic analysis of the different Sequence Types (ST) was performed. A total of 4 different ST were identified. The most frequently found was ST1 present in 66% of samples. Additionally, two samples presented a new allelic profile, belonging to new STs (ST 9 and ST 10), which were closely related to ST1. Conclusions/Significance The present data demonstrate that B. bacilliformis MLST studies may be possible directly from blood samples, being a promising approach for epidemiological studies. During the outbreak the STs of B. bacilliformis were found to be heterogeneous, albeit closely related, probably reflecting the evolution from a common ancestor colonizing the area. Additional studies including new samples and areas are needed, in order to obtain better knowledge of phylogenetic scenario B. bacilliformis.

Whole-genome sequencing of two Bartonella bacilliformis strains.

Abstract: Bartonella bacilliformis is the causative agent of Carrion9s disease, a highly endemic human bartonellosis in Peru. We performed a whole-genome assembly of two B. bacilliformis strains isolated from the blood of infected patients in the acute phase of Carrion9s disease from the Cusco and Piura regions in Peru.