Antimicrobial susceptibility of bacteraemic isolates of Salmonella enterica serovar typhi and paratyphi infection in Pakistan from 2017-2020.

OBJECTIVE: To determine the antibacterial susceptibility pattern of bacteraemia isolates of Salmonella enterica serovar typhi and paratyphi. METHODS: The retrospective descriptive observational study was conducted at the Microbiology section of Dow Diagnostic Research and Reference Laboratory, and comprised blood culture reports from January 1, 2017, to Dec 30, 2020, which were screened for the presence of Salmonella typhi and paratyphi growth The frequency of the isolates and their antibiotic resistance patterns were analysed. Data was analysed using SPSS 20. RESULTS: Of the 174,190 blood culture samples, 62,709(36%) were positive for bacterial growth. Salmonella were isolated in 8,689(13.8%) samples of which 8,041(92.5%) were Salmonella typhi, 529(6%) were Salmonella paratyphi A and 119(1.3%) were Salmonella paratyphi B. There was a drastic increase in resistance to third-generation cephalosporin in Salmonella typhi from 71(12.8%) in 2017 to 1,420(71%) in 2018, 2,850(74.6%) in 2019 and 1,251(77%) in 2020. All isolates were sensitive to meropenem and azithromycin. CONCLUSIONS: A high number of extensively drug-resistant typhoid cases due to Salmonella typhi were found. All isolates were sensitive to meropenem and azithromycin.

Distribution of the invasive pathogenic isolates in blood culture with their antimicrobial susceptibility pattern in a diagnostic laboratory in Karachi.

OBJECTIVE: To determine the frequent bacterial pathogens causing blood stream infections in various age brackets, and to discover their antibiotic susceptibility pattern. METHODS: The retrospective, descriptive, observational, cross-sectional study was conducted at the microbiology laboratory of Patel Hospital, Karachi, and comprised positive blood culture bacterial isolates analysed between July 1, 2018, and June 30, 2019. Standard microbiological techniques were employed for the identification and antimicrobial susceptibility testing. Data was analysed using SPSS 20. RESULTS: Of the 3450 specimen, 1243(36%) were positive; 668(53.7%) from male and 575(46.3%) from female subjects, and 771(62%) were gram-positive whereas 472(38%).were gram-negative. Salmonella typhi was the most common pathogen 139(11.1) among gram-negative organisms, followed by Acinetobacter species 103(8.2%), Escherichia coli 96(7.7%) and Klebsiella species 42(3.4%). Among gram-positive bacteria, the predominant isolates were staphylococcus epidermidis 650(52%), staphylococcus aureus 67(5.4%) and enterococci 28(2.3%). Linezolid (99.8%), vancomycin (99%) and chloramphenicol (69%) were found to be the most sensitive antibiotics among gram-positive cocci. Meropenem (60%), amikacin (46%) and gentamicin (40%) were the most sensitive antibiotics for multidrug resistant gram-negative bacteria. CONCLUSIONS: The identification of frequent bacterial pathogens in blood cultures of patients may guide clinicians in proper empirical selection of antibiotics in patients with bacteraemia.

In vitro evaluation of antimicrobial effect of miswak against common oral pathogens.

BACKGROUND AND OBJECTIVE: Miswak is a natural tooth cleaning tool which is being used in many parts of the world since ancient times. It is known to be useful in prevention of dental caries. But still it is not used as frequently as other oral hygiene tools. This research was designed to scientifically establish antimicrobial effect of miswak in vitro against common oral pathogens. METHODS: This was a cross-sectional study involving 100 health care workers. This research was carried out in Microbiology section of Dow Diagnostic Research & Reference Laboratory. A questionnaire was designed to test oral hygiene habits of study subjects. Oral swabs were taken and microorganisms were identified by standard bacteriological methods. Test material included four different types of miswaks i.e. (1) root of the peelu (Salvadora persica) tree (in packing) (2) root of the peelu tree (without packing) (3) stem of the peelu tree & (4) stem of the neem (Azadirechta indica) tree. These miswaks were tested against three different types of microorganisms isolated from oral swabs: Staphylococcus aureus, Streptococcus mutans & Candida albicans by agar diffusion method. Inhibition zone was measured after 24 hrs of incubation at 37(o)C. RESULTS: Among the miswaks used, root of the peelu tree in both packing and without packing exhibited strong antimicrobial effect against all three tested microorganisms. However miswak taken from the stem of the peelu and neem tree did not show any antimicrobial activity against all three types of the tested microorganisms. CONCLUSION: Miswak taken from the root of the peelu tree exhibited antimicrobial activity against all the common oral pathogens and could be a good oral hygiene tool in combating dental caries.