Second nationwide anti-tuberculosis drug resistance survey in Namibia.

SETTING: Namibia ranks among the 30 high TB burden countries worldwide. Here, we report results of the second nationwide anti-TB drug resistance survey.OBJECTIVE: To assess the prevalence and trends of multidrug-resistant TB (MDR-TB) in Namibia.METHODS: From 2014 to 2015, patients with presumptive TB in all regions of Namibia had sputum subjected to mycobacterial culture and phenotypic drug susceptibility testing (DST) for rifampicin, isoniazid, ethambutol and streptomycin if positive on smear microscopy and/or Xpert MTB/RIF.RESULTS: Of the 4124 eligible for culture, 3279 (79.5%) had Mycobacterium tuberculosis isolated. 3126 (95%) had a first-line DST completed (2392 new patients, 699 previously treated patients, 35 with unknown treatment history). MDR-TB was detected in 4.5% (95%CI 3.7-5.4) of new patients, and 7.9% (95%CI 6.0-10.1) of individuals treated previously. MDR-TB was significantly associated with previous treatment (OR 1.8, 95%CI 1.3-2.5) but not with HIV infection, sex, age or other demographic factors. Prior treatment failure demonstrated the strongest association with MDR-TB (OR 17.6, 95%CI 5.3-58.7).CONCLUSION: The prevalence of MDR-TB among new TB patients in Namibia is high and, compared with the first drug resistance survey, has decreased significantly among those treated previously. Namibia should implement routine screening of drug resistance among all TB patients.

A possible signal-coupling role for cyclic AMP during endocytosis in Amoeba proteus.

Cytoplasmic levels of cAMP in Amoeba proteus were measured utilizing radioimmunoassays under control conditions and when stimulated by inducers of either pinocytosis or phagocytosis. In control cells, cytoplasmic cAMP levels were approximately 0.39 pM/mg cells. When exposed to either chemotactic peptide or mannose which stimulate phagocytosis in the amoeba, there is a rapid doubling of the cAMP level within 45 sec of stimulation which then returns to the control level within 3-5 min. Theophylline prolongs the elevation of cytoplasmic cAMP in stimulated cells and is also capable of eliciting food vacuole formation in the amoeba. In addition isoproterenol also causes food vacuole formation in the amoeba as well as a large and prolonged increase in cytoplasmic cAMP levels. Inducers of pinocytosis (BSA and Na Cl) also elicit changes in cytoplasmic cAMP in the amoeba, but the response appears to differ from that elicited by inducers of phagocytosis in that the peak cAMP levels are broader and biphasic. It is concluded that cAMP plays a signal-coupling role during the early phases of both forms of endocytosis in Amoeba proteus.