Search

Multidrug-resistant tuberculosis (MDR) continues to pose a threat to public health. Previously, we identified a cationic host defense peptide with activity against Mycobacterium tuberculosis in vivo and with a bactericidal effect against MDR M. tuberculosis at therapeutic concentrations. To understand the mechanisms of this peptide, we investigated its interactions with live M. tuberculosis and liposomes as a model. Peptide interactions with M. tuberculosis inner membranes induced tube-shaped membranous structures and massive vesicle formation, thus leading to bubbling cell death and ghost cell formation. Liposomal studies revealed that peptide insertion into inner membranes induced changes in the peptides' secondary structure and that the membranes were pulled such that they aggregated without permeabilization, suggesting that the peptide has a strong inner membrane affinity. Finally, the peptide targeted essential proteins in M. tuberculosis, such as 60 kDa chaperonins and elongation factor Tu, that are involved in mycolic acid synthesis and protein folding, which had an impact on bacterial proliferation. The observed multifaceted targeting provides additional support for the therapeutic potential of this peptide.

The World Health Organization strongly recommends regular screening for tuberculosis (TB) in HIV-positive individuals.

Detection of active tuberculosis (TB) before antiretroviral therapy (ART) initiation is important, but optimal diagnostic methods for use in resource-limited settings are lacking. We assessed the prevalence of TB, evaluated the diagnostic yield of Xpert MTB/RIF in comparison with smear microscopy and culture, and the impact of Xpert results on clinical management in HIV-positive adults eligible for ART at health centers in a region of Ethiopia.

Antiretroviral therapy (ART) initiation during treatment for tuberculosis (TB) improves survival in human immunodeficiency virus (HIV)/TB-coinfected patients. We compared virological suppression (VS) rates, mortality, and retention in care in HIV-positive adults receiving care in 5 Ethiopian health centers with regard to TB coinfection.

Background: Mycobacterium goodii is a rare cause of significant infection. M. goodii has mainly been associated with lymphadenitis, cellulitis, osteomyelitis, and wound infection. Case presentation: A case of a 76-year-old Caucasian female is presented. The patient developed a prosthetic valve endocarditis caused by M. goodii. She had also suffered from severe neurological symptoms related to a septic emboli that could be demonstrated as an ischemic lesion found on CT of the brain. Transesophageal echocardiography verified a large vegetation attached to the prosthetic valve. Commonly used blood culture bottles showed growth of the bacteria after 3 days. Conclusions: Although M. goodii is rarely involved in these kinds of severe infections, rapidly growing mycobacteria should be recognized during conventional bacterial investigations and identified by molecular tools such as analysis of 16S rDNA. Species identification of nontuberculous mycobacteria is demanding and is preferably done in collaboration with a mycobacterial laboratory. An early diagnosis provides the opportunity for adequate treatment. In the present case, prolonged antimicrobial treatment and surgery with replacement of the prosthetic valve was successful.

Background: A breeding colony of IL-10 deficient B6.129P2-Il10(tmICgn/J) mice, kept under conventional conditions, developed an inflammatory bowel-like disease (IBD) with rectal prolapse and blood tinged diarrhoea. No clinical signs of disease were observed at the time of arrival to our animal house. These animals were originally planned to serve as a negative control group in an experimental infection study with Helicobacter species to investigate colonization of the murine gut. Results: A spiral-shaped, Gram-negative bacterium was isolated from the breeding mice colony. In a first group of six animals, tissue specimens from the liver, small and large intestines, faeces and blood, were analysed by culture, PCR-denaturing gradient gel electrophoresis (PCR-DGGE), species-specific PCR assays and DNA-sequencing, histology and serology. Helicobacter ganmani, but no other Helicobacter species, was isolated from the liver, small bowel, caecum, colon and faeces. We found inflammation in caeca, colon and livers, most pronounced in the caecal areas of culture positive mice with a severe typhlitis with cystic dilatation of glandular structures and irregular crypt architecture. Some animals showed a pronounced colitis with mucosal and sub-mucosal inflammatory infiltrates. Other animals displayed large lymphoid infiltrates in the livers and hepatitis. Tissue samples and sera from 18 additional animals from the same breeding colony were analysed by the same methods, except for culture. H. ganmani was identified by PCR in most tissue samples of the 18 additional animals as well. Sero-conversion to H. ganmani correlated well with histopathological changes. Conclusions: Our findings emphasize the importance of using Helicobacter-free animals to develop murine models of chronic hepatitis and colitis.