Genotyping Klebsiella pneumoniae isolated from hepatic abscesses in three patients from Bogota, Colombia / Genotipificación de Klebsiella pneumoniae aislada de abscesos hepáticos de pacientes de Bogotá, Colombia / Genotipificação de Klebsiella pneumoniae isolada de abscessos hepáticos de pacientes de Bogotá, Colômbia

Pyogenic liver abscess caused by Klebsiella pneumoniae represents an ever increasing entity which has mainly been described as occurring in Asia, even though, on a smaller scale, cases are being more frequently described from the USA and Europe, 13% overall mortality being reached worldwide. Affected patients are severely sick, suffering from fever, sweating, having increased acute phase reactants and risk factors such as Diabetes Mellitus, alcoholism and the inherent characteristics of the bacteria causing the disease. Objective: in this work we used a Multilocus Sequencing Typing (MLST), a nucleotide sequence-based method in order to characterize the genetic relationships among bacterial isolates. Materials and methods: the report is focused on three cases involving patients suffering from pyogenic liver abscess caused by Klebsiella pneumoniae in two hospitals in Bogota, Colombia, where phenotyping and hypermucoviscosity studies were carried out, as well as the genotyping of cultured Klebsiella isolates. Results: it was found that the isolated microorganism in cases I and II corresponded to the same K. pneumoniae strain, having 100% sequence identity for the 5 genes being studied while the strain in Case III was genotypically different. Conclusion: it is important to carry out multidisciplinary studies allowing all pyogenic liver abscess cases reported in Colombia to be complied to ascertain the frequency of microorganisms causing this pathology in our country, as well as a genotyping study of different K. pneumoniae strains to compare them and confirm clonal and pathogenicity relationships through housekeeping gene analysis.

El absceso hepático piógeno causado por Klebsiella pneumoniae representa una entidad descrita con frecuencia en los países asiáticos y, en menor escala, también en Estados Unidos y Europa. En el ámbito mundial su mortalidad alcanza a un 13%. Los pacientes pueden presentar un compromiso severo, el cual cursa con fiebre, sudoración y aumento de reactantes de fase aguda, sobre todo en individuos con factores de riesgo como la diabetes mellitus y el alcoholismo, además de las características inherentes de la bacteria responsable de la infección. Objetivo: a continuación se presentan tres casos de pacientes con absceso hepático piógeno causado por Klebsiella pneumoniae en dos hospitales de Bogotá. Materiales y métodos: se realizó caracterización molecular de los aislados de Klebsiella mediante la técnica de Multilocus Secquence Typing (MLST), análisis fenotípicos y de hipermucoviscosidad. Resultado: se encontró que el microorganismo aislado en los casos I y II corresponde a la misma cepa de K. pneumoniae, que tiene 100% de identidad de secuencia de los 5 genes en estudio mientras que la cepa en Case III fue genotípicamente diferente. Conclusión: es importante llevar a cabo estudios multidisciplinarios que incluyan todos los casos de abscesos hepáticos piógenos reportados en Colombia con el objeto de determinar la frecuencia de los microorganismos causantes de esta patología en nuestro país, así como un estudio de genotipificación de diferentes cepas de K. pneumoniae para confirmar las relaciones clonales y de patogenicidad.

O abscesso hepático piogênico causado por Klebsiella pneumoniae representa uma entidade descrita com frequência nos países asiáticos e, em menor escala, também nos Estados Unidos e na Europa. No âmbito mundial sua mortalidade alcança um 13%. Os pacientes podem apresentar um compromisso severo, o qual cursa com febre, sudoração e aumento de reagentes de fase aguda, especialmente em indivíduos com fatores de risco como a diabetes mellitus e o alcoolismo, além das características inerentes da bactéria responsável da infecção. Objetivo: a continuação apresentamse três casos de pacientes com abscesso hepático piogênico causado por Klebsiella pneumoniae em dois hospitais de Bogotá; Materiais e métodos: realizou-se caracterização molecular dos isolados de Klebsiella mediante a técnica de Multilocus Secquence Typing (MLST), análises fenotípicas e de hipermucoviscosidade. Resultado: encontrou-se que o micro-organismo isolado nos casos I e II corresponde à mesma cepa de K. pneumoniae, que tem 100% de identidade de sequencia dos 5 genes em estudo enquanto a cepa no caso III foi genotipicamente diferente. Conclusão: é importante levar a cabo estudos multidisciplinares que incluam todos os casos de abscessos hepáticos piogênicos reportados na Colômbia com o objeto de determinar a frequência dos micro-organismos causadores desta patologia em nosso país, assim como um estudo de genotipificação de diferentes cepas de K. pneumoniae para confirmar as relações clonais e de patogenicidade.

Bacterial translocation in abdominal trauma and postoperative infections.

BACKGROUND: Bacterial translocation (BT) describes the passage of bacteria residing into the gastrointestinal tract, through the intestinal mucosa barrier to sterile tissues such as mesenteric lymph nodes (MLN) and other organs. This phenomenon has not been thoroughly studied in patients with trauma to date, and an association between BT and postoperative infection has not been well established so far. METHODS: MLNs from 36 patients with abdominal trauma were removed during laparotomy and cultured to detect BT. Postoperative infectious complications in these patients were registered, and both phenotypical and molecular typings (through multilocus sequencing) were carried out for microorganisms isolated from MLN and postoperative infection sites. Associations between clinical variables, BT presence, and postoperative infection development were established. RESULTS: BT was detected in 33% of the patients (n = 12). Postoperative infections were present in 22.2% of the patients (n = 8). A significant statistical difference was found between postoperative infections in patients with BT evidence (41.6%), when compared with patients without BT (12.5%; p = 0.047). Bacteria isolated from infection sites were the same as those cultured in MLN in 40% of the cases (n = 2 of 5), allowing us to establish causality between BT and postoperative infection. CONCLUSIONS: There is higher risk of BT in trauma patients, and it is associated with a significant increase of postoperative infections. An abdominal trauma index ≥10 was found to be associated with the development of BT. This is the first study describing BT among patients with abdominal trauma, where causality is confirmed at molecular level.

Low genetic polymorphism of merozoite surface proteins 7 and 10 in Colombian Plasmodium vivax isolates.

The merozoite surface protein (MSP) family is involved in the initial interaction between merozoites and erythrocytes in Plasmodium species, its members are therefore becoming major targets for vaccine development. Considering that antigens included in a subunit malaria vaccine should be both accessible to the immune system and lack genetic diversity or have very limited polymorphism, we have analyzed the genetic diversity of three msp genes (msp-7A, msp-7K and msp-10) in different geographical regions of Colombia. The results showed that these genes follow the neutral model of evolution and also display low genetic diversity. The strong conservation found for msp-7 haplotypes in isolates from geographically different regions further suggests that these proteins could be good components of a vaccine against Plasmodium vivax malaria, thereby avoiding strain-specific immune responses.