Analysis of existence of multidrug-resistant H58 gene in Salmonella enterica serovar Typhi isolated from typhoid fever patients in Makassar, Indonesia.

The surveillance of multidrug-resistant (MDR) H58 typhoid is highly important, especially in endemic areas. MDR strain detection is needed by using a simple PCR technique that only uses a pair of primers. This is conducted considering the detection of Salmonella Typhi strains that have been carried out so far are only using antimicrobial sensitivity tests to determine microbial resistance phenotypically and to determine genotypically using complex molecular techniques. We aimed to analyse the existence of Salmonella Typhi MDR H58 in patients with typhoid fever in Makassar, Indonesia. A total of 367 blood samples of typhoid fever patients were collected from April 2018 until April 2019. The blood sample was cultured, then confirmed via simple PCR. All of the confirmed samples were tested for susceptibility against antibiotics and molecularly analysed for MDR H58 existence using a simple PCR technique. We found 7% (27/367) of the samples to be positive by both blood culture and PCR. All 27 isolates were found to be sensitive to sulfamethoxazole/trimethoprim. The lowest drug sensitivities were to amoxicillin, at one (3.7%) of 27 isolates, and ampicillin, at 13 (48.1%) of 27 isolates. Salmonella Typhi H58 PCR results showed that one (3.7%) of 27 isolates carried a positive fragment of 993 bp that led to the H58 strain, since the deletion flanks this fragment. The isolate was also found to be resistant to amoxicillin and fluoroquinolone according to a sensitivity test. Further molecular analysis needs to be conducted to examine the single isolate that carried the 933 bp fragment.

The effect of anti-tuberculosis drugs therapy on mRNA efflux pump gene expression of Rv1250 in Mycobacterium tuberculosis collected from tuberculosis patients.

Efflux pumps are transmembrane proteins that vigorously participate in extruding a wide range of substrates, including drugs, outside the bacterial cell. We aimed to investigate the mRNA expression level of the Rv1250 efflux pump gene in Mycobacterium tuberculosis isolated from individuals with tuberculosis who received drug therapy, at the 1st, 3rd and 5th months, and newly diagnosed patients with tuberculosis who will receive drug therapy (0 month). The study was a multiple cross-sectional longitudinal design-50 different M. tuberculosis isolates and a reference strain H37Rv were subcultured in LJ medium and confirmed by multiplex PCR for identification of M. tuberculosis and collected for RNA extraction. Total bacterial mRNA was analysed using real-time quantitative PCR to evaluate mRNA quantification gene expression. There were differences in the level of Rv1250 mRNA expression between sensitive (n = 11) and resistant (n = 40) groups of 5.961 ± 0.414 and 10.192 ± 1.978, respectively (fold changes; p < 0.05). There were significant differences of expression level among M. tuberculosis-resistant groups (p < 0.05) specifically 7.573 ± 0.424 for 0-month drug therapy (n = 10), 9.438 ± 0.644 for 1st month drug therapy (n = 10), 11.057 ± 0.262 for 3rd month drug therapy (n = 10) and 12.701 ± 0.460 for 5th month drug therapy (n = 10). We assume that the extent of Rv1250 gene expression in M. tuberculosis clinical isolates is a result of the exposure to antimicrobials during treatment, which affect the basic expression of the efflux pump Rv1250 gene.