Extended-spectrum β-lactamase blaCTX-M-1 group in gram-negative bacteria colonizing patients admitted at Mazimbu hospital and Morogoro Regional hospital in Morogoro, Tanzania.

Of the 285 patients investigated, 123 (43.2%) carried ESBL-GNB in their intestines. Five of the 123 ESBL positive patients were colonized with two different bacteria, making a total of 128 ESBL producing isolates. Escherichia coli (n = 95, 74.2%) formed the majority of ESBL isolates. The proportion of CTX-M-1 group genes among ESBL isolates tested was 94.9% (93/98). History of antibiotic use (OR: 1.83, 95% CI: 1.1-3.2, P = 0.03), being on antibiotic treatment (OR: 2.61, 95% CI: 1.5-4.53, P = 0.001), duration of hospital stay (OR: 1.2, 95% CI: 1.1-1.3, P < 0.001) and history of previous admission (OR: 2.24, 95% CI: 1.2-4.1, P = 0.009) independently predicted ESBL-GNB carriage.