Pandoraea sp infection in a lung transplant patient and the critical role of MALDI-TOF in accurate bacterial identification.

Diagnosis and clinical management of pulmonary infections in lung transplant patients are challenging. The increased diversity of bacterial species identified from clinical samples with novel proteomics-based systems can further complicate clinical decision making in this highly vulnerable population. Whether newly recognized organisms are colonizers or true pathogens often remains controversial since symptoms causality and impact on lung function is often unknown. We present the case of a 48-year-old female lung transplant patient with Pandoraea sp infection. We review and discuss the role of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for accurate bacterial identification. We report on therapeutic management and clinical outcome.

Il est difficile de diagnostiquer et d'assurer la prise en charge clinique des infections pulmonaires chez les patients ayant une transplantation pulmonaire. La diversité accrue des espèces bactériennes identifiées dans des échantillons cliniques contenant de nouveaux systèmes protéomiques peut compliquer encore les décisions cliniques dans cette population hautement vulnérable. On ne sait pas exactement si les nouvelles formes d'organismes sont des colonisateurs ou de véritables agents pathogènes puisque, dans bien des cas, on ne connaît ni la cause ni l'impact des symptômes sur la fonction pulmonaire. Les auteurs présentent le cas d'une femme de 48 ans ayant une transplantation pulmonaire atteinte d'une infection par une espèce à Pandoraea. Ils analysent et exposent le rôle de la spectrométrie de masse par désorption-ionisation laser assistée par matrice pour bien identifier la bactérie. Ils rendent compte de la prise en charge thérapeutique et des résultats cliniques de cette patiente.

Plesiomonas shigelloides: An Unusual Cause of Septic Abortion.

Plesiomonas shigelloides, the only oxidase-positive Enterobacteriaceae, is an inhabitant of freshwater and estuary ecosystems. We report the first possible case of Plesiomonas shigelloides-induced septic abortion. This 24-year-old female was successfully treated by dilatation and curettage as well as antimicrobial therapy.

Polymorphism of the capsid L1 gene of human papillomavirus types 31, 33, and 35.

The L1 gene encodes for the major capsid protein of human papillomaviruses (HPV). There is limited information on the polymorphism of L1 for types related to HPV-16. This report explores the polymorphism of L1 in phylogenetically related types 31, 33, and 35 compared to HPV-16. Genital specimens collected from 732 HIV-seropositive and 323 HIV-seronegative women were screened for HPV DNA with consensus L1 PCR. Cervical samples positive for HPV-16 (n = 74), HPV-31 (n = 78), HPV-33 (n = 37), and HPV-35 (n = 58) were further characterized by PCR-sequencing of the complete L1 gene. The number of nucleotide substitutions within L1 ranged from 19 for HPV-33 to 52 for HPV-31. The ratio of the number of variants/number of isolates tested was higher for HPV-31 (56.4%, P = 0.05) and HPV-35 (60.3%, P = 0.04) compared to HPV-16 (40.5%), while this ratio was lower for HPV-33 (24.3%), although not significantly (P = 0.14). The maximal distance between HPV variants was greater in the five putative surface-exposed loops of L1 than in sequences outside the loops (P < 0.01). Synonymous variations were encountered in 1.7% (95% CI 1.1-2.3) of nucleotides inside the L1 loops and 2.4% (95% CI1.2-3.7) of nucleotides outside the L1 loops. Non-synonymous variations were encountered in 1.8% (95% CI 1.1-2.5) of nucleotides within the L1 loops and 0.2% (95% CI 0-0.4) of nucleotides outside the loops. dN/dS ratios were below 1.0 in extra-loop and intra-loop regions, but they were lower in extra-loop regions. These results suggest that sequences within and outside the hypervariable loops of L1 were under selective constraint.

Antineoplastic properties of bacteriocins: revisiting potential active agents.

Bacteriocins are antimicrobial peptides produced by a wide range of bacteria. Their antineoplastic properties have been inadequately revealed in the late 70s by using crude bacteriocin preparation toxic to mammalian cells. Nowadays, purified bacteriocins are available and have shown inhibitory properties toward diverse neoplastic line cells. Pyocin, colicin, pediocin, and microcin are among bacteriocins reported to present such activity. Moreover, modified bacteriocins proved to be effective in a glioblastoma xenograft mouse model. Screening for the presence of bacteriocin in colon cancer subjects has been studied with mixed results. Bacteriocin use as a therapeutic agent or in a prevention setting is discussed specifically evaluating bacteriocins biochemical properties and recent advances in peptide therapeutics.

Capacity of human nisin- and pediocin-producing lactic Acid bacteria to reduce intestinal colonization by vancomycin-resistant enterococci.

This study demonstrated the capacity of bacteriocin-producing lactic acid bacteria (LAB) to reduce intestinal colonization by vancomycin-resistant enterococci (VRE) in a mouse model. Lactococcus lactis MM19 and Pediococcus acidilactici MM33 are bacteriocin producers isolated from human feces. The bacteriocin secreted by P. acidilactici is identical to pediocin PA-1/AcH, while PCR analysis demonstrated that L. lactis harbors the nisin Z gene. LAB were acid and bile tolerant when assayed under simulated gastrointestinal conditions. A well diffusion assay using supernatants from LAB demonstrated strong activity against a clinical isolate of VRE. A first in vivo study was done using C57BL/6 mice that received daily intragastric doses of L. lactis MM19, P. acidilactici MM33, P. acidilactici MM33A (a pediocin mutant that had lost its ability to produce pediocin), or phosphate-buffered saline (PBS) for 18 days. This study showed that L. lactis and P. acidilactici MM33A increased the concentrations of total LAB and anaerobes while P. acidilactici MM33 decreased the Enterobacteriaceae populations. A second in vivo study was done using VRE-colonized mice that received the same inocula as those in the previous study for 16 days. In L. lactis-fed mice, fecal VRE levels 1.73 and 2.50 log(10) CFU/g lower than those in the PBS group were observed at 1 and 3 days postinfection. In the P. acidilactici MM33-fed mice, no reduction was observed at 1 day postinfection but a reduction of 1.85 log(10) CFU/g was measured at 3 days postinfection. Levels of VRE in both groups of mice treated with bacteriocin-producing LAB were undetectable at 6 days postinfection. No significant difference in mice fed the pediocin-negative strain compared to the control group was observed. This is the first demonstration that human L. lactis and P. acidilactici nisin- and pediocin-producing strains can reduce VRE intestinal colonization.

A new insertion mutation in the beta-globin gene [codons 45/46 (+A)] resulting in a beta-thalassemia minor phenotype.

The beta-globin gene of 306 newly diagnosed beta-thalassemia (thal) minor patients were sequenced. Analysis revealed that only one amongst all the identified mutations had not been previously reported. This new mutation, causing a beta(+)-thal minor phenotype, was found in a patient of Arabic origin. The insertion frameshift mutation (+A) between codons 45 and 46 [codons 45/46 (+A)] results in a premature termination signal at codon 52. No truncated beta-globin or abnormal hemoglobin (Hb) was identified.