Retrospective Analysis of Archived Pyrazinamide Resistant Complex Isolates from Uganda-Evidence of Interspecies Transmission.

The contribution of to the proportion of tuberculosis cases in humans is unknown. A retrospective study was undertaken on archived complex (MTBC) isolates from a reference laboratory in Uganda to identify the prevalence of human infection. A total of 5676 isolates maintained in this repository were queried and 136 isolates were identified as pyrazinamide resistant, a hallmark phenotype of .

Methylfolate Trap Promotes Bacterial Thymineless Death by Sulfa Drugs.

The methylfolate trap, a metabolic blockage associated with anemia, neural tube defects, Alzheimer's dementia, cardiovascular diseases, and cancer, was discovered in the 1960s, linking the metabolism of folate, vitamin B12, methionine and homocysteine. However, the existence or physiological significance of this phenomenon has been unknown in bacteria, which synthesize folate de novo. Here we identify the methylfolate trap as a novel determinant of the bacterial intrinsic death by sulfonamides, antibiotics that block de novo folate synthesis.

Draft Genome Sequences of Mycobacterium bovis BZ 31150 and Mycobacterium bovis B2 7505, Pathogenic Bacteria Isolated from Archived Captive Animal Bronchial Washes and Human Sputum Samples in Uganda.

Bovine tuberculosis (BTB), a zoonotic infection of cattle caused by Mycobacterium bovis, results in losses of $3 billion to the global agricultural industry and represents the fourth most important livestock disease worldwide. M. bovis as a source of human infection is likely underreported due to the culture medium conditions used to isolate the organism from sputum or other sample sources.

Incubation time of Mycobacterium tuberculosis complex sputum cultures in BACTEC MGIT 960: 4weeks of negative culture is enough for physicians to consider alternative diagnoses.

We retrospectively analyzed time to detection of 3747 positive MGIT sputum cultures at a laboratory in a country with heavy burden of tuberculosis. Ninety-nine percent of diagnostic cultures turned positive within 28days, suggesting that physicians may consider alternative diagnoses if sputum cultures remain negative after 4weeks of incubation.

Sulfamethoxazole susceptibility of Mycobacterium tuberculosis isolates from HIV-infected Ugandan adults with tuberculosis taking trimethoprim-sulfamethoxazole prophylaxis.

Additional drugs are needed for the treatment of multidrug-resistant tuberculosis (TB). Sulfamethoxazole has been shown to have in vitro activity against Mycobacterium tuberculosis; however, there is concern about resistance given the widespread use of trimethoprim-sulfamethoxazole prophylaxis among HIV-infected patients in sub-Saharan Africa. Thirty-eight of 40 Mycobacterium tuberculosis isolates (95%) from pretreatment sputum samples from Ugandan adults with pulmonary TB, including HIV-infected patients taking trimethoprim-sulfamethoxazole prophylaxis, were susceptible with MICs of ≤38.

Use of real time polymerase chain reaction for detection of M. tuberculosis, M. avium and M. kansasii from clinical specimens.

Background: The incidence of M. tuberculosis (MTB) and non tuberculous Mycobacterium species (NTMs) like M. avium and M.

Comparison of MGIT and Myco/F lytic liquid-based blood culture systems for recovery of Mycobacterium tuberculosis from pleural fluid.

The specificities and sensitivities of the Bactec mycobacterial growth indicator tube (MGIT) system for the recovery of Mycobacterium tuberculosis from pleural fluid are not statistically different than those of the Myco/F lytic liquid culture system. The time to positivity is shorter in the MGIT system (12.7 versus 20.

Elucidating emergence and transmission of multidrug-resistant tuberculosis in treatment experienced patients by whole genome sequencing.

Background: Understanding the emergence and spread of multidrug-resistant tuberculosis (MDR-TB) is crucial for its control. MDR-TB in previously treated patients is generally attributed to the selection of drug resistant mutants during inadequate therapy rather than transmission of a resistant strain. Traditional genotyping methods are not sufficient to distinguish strains in populations with a high burden of tuberculosis and it has previously been difficult to assess the degree of transmission in these settings.

Bacterial conversion of folinic acid is required for antifolate resistance.

Antifolates, which are among the first antimicrobial agents invented, inhibit cell growth by creating an intracellular state of folate deficiency. Clinical resistance to antifolates has been mainly attributed to mutations that alter structure or expression of enzymes involved in de novo folate synthesis. We identified a Mycobacterium smegmatis mutant, named FUEL (which stands for folate utilization enzyme for leucovorin), that is hypersusceptible to antifolates.

A lipoprotein modulates activity of the MtrAB two-component system to provide intrinsic multidrug resistance, cytokinetic control and cell wall homeostasis in Mycobacterium.

The MtrAB signal transduction system, which participates in multiple cellular processes related to growth and cell wall homeostasis, is the only two-component system known to be essential in Mycobacterium. In a screen for antibiotic resistance determinants in Mycobacterium smegmatis, we identified a multidrug-sensitive mutant with a transposon insertion in lpqB, the gene located immediately downstream of mtrA-mtrB. The lpqB mutant exhibited increased cell-cell aggregation and severe defects in surface motility and biofilm growth.

Comparison of rapid tests for detection of rifampicin-resistant Mycobacterium tuberculosis in Kampala, Uganda.

Background: Drug resistant tuberculosis (TB) is a growing concern worldwide. Rapid detection of resistance expedites appropriate intervention to control the disease. Several technologies have recently been reported to detect rifampicin resistant Mycobacterium tuberculosis directly in sputum samples.

Protein kinase G is required for intrinsic antibiotic resistance in mycobacteria.

Antibiotic resistance and virulence of pathogenic mycobacteria are phenotypically associated, but the underlying genetic linkage has not been known. Here we show that PknG, a eukaryotic-type protein kinase previously found to support survival of mycobacteria in host cells, is required for the intrinsic resistance of mycobacterial species to multiple antibiotics.

Rate and amplification of drug resistance among previously-treated patients with tuberculosis in Kampala, Uganda.

Background: Drug-resistant Mycobacterium tuberculosis has emerged as a global threat. In resource-constrained settings, patients with a history of tuberculosis (TB) treatment may have drug-resistant disease and may experience poor outcomes. There is a need to measure the extent of and risk factors for drug resistance in such patients.

Low-cost rapid detection of rifampicin resistant tuberculosis using bacteriophage in Kampala, Uganda.

Background: Resistance to anti-tuberculosis drugs is a serious public health problem. Multi-drug resistant tuberculosis (MDR-TB), defined as resistance to at least rifampicin and isoniazid, has been reported in all regions of the world. Current phenotypic methods of assessing drug susceptibility of M.