Introduction: This study aimed to determine the drug susceptibility patterns and genetic elements related to drug resistance in isolates of Salmonella enterica serovar Typhi (S. Typhi) from the Faisalabad region of Pakistan. Methodology: The drug resistance status of 80 isolates were evaluated by determining antimicrobial susceptibility, MICs, drug resistance genes involved, and the presence of integrons. Nalidixic acid resistance and reduced susceptibility to ciprofloxacin were also investigated by mutation screening of the gyrA, gyrB, parC, and parE genes. Results: Forty-seven (58.7%) isolates were multidrug resistant (MDR). Among the different resistance (R) types, the most commonly observed (13/80) was AmChStrTeSxtSmzTmp, which is the most frequent type observed in India and Pakistan. The most common drug resistant genes were bla cat, tetB, sul1, sul2, and dfrA7. Among the detected genes, only dfrA7 was found to be associated in the form of a single gene cassette within the class 1 integrons. Conclusions: MIC determination of currently used drugs revealed fourth-generation gatifloxacin as an effective drug against multidrugresistant S. Typhi, but its clinical use is controversial. The Ser83→Phe substitution in gyrA was the predominant alteration in nalidixic acidresistant isolates, exhibiting reduced susceptibility and increased MICs against ciprofloxacin. No mutations in gyrB, parC, or parE were detected in any isolate.

Escherichia coli are one of the leading causes of infection in wounds. Emerging multiple drug resistance among E. coli poses a serious challenge to antimicrobial therapy for wounds. This study was conducted to ascertain a baseline profile of antimicrobial resistance in E. coli isolates infecting surgical wounds. A total of 64 pus samples from hospitalized patients were screened and 29 (45.3%) were found to have E. coli, which were identified biochemically and confirmed by molecular methods. Using the disc diffusion method, antimicrobial resistance was observed toward tetracycline (100%), cefradine (100%), nalidixic acid (93.1%), ampicillin (86.2%), gentamicin (86.2%), cefixime (82.8%), ceftriaxone (82.8%), aztreonam (82.8%), ciprofloxacin (75.9%), streptomycin (72.4%), cefoperazone (65.5%), chloramphenicol (58.6%) and amikacin (58.6%). In an effort to find relevant genes, 11 different genes were targeted by PCR. Among these, the mutated gyrA gene was found to be the most prevalent (82.8%), followed by the TEM (72.4%), catP (68.9%), catA1 (68.9%), tetB (62.1%), blt (58.6%), bla CTXÀMÀ15 (27.6%), bla TEM (20.7%), bla OXA (17.2%), tetA (17.2%) and aadA1 (13.8%) genes. The presence of integrons was also studied among these isolates. The prevalence of class 1 integrons was the highest (44.8%), followed by class 2 (27.6%). Three (10.3%) isolates carried both class 1 and class 2 integrons (first report from E. coli infecting wounds). The high incidence of integrons points toward their facilitation for carriage of antimicrobial resistance genes; however, in nearly 37% isolates, no integrons were detected, indicating the significance of alternative mechanisms of gene transfer. Another salient finding was that all isolates were multidrug-resistant E. coli.

Background: Drug resistance is a major problem in Escherichia coli isolated from surgical wound infections. In this study, we evaluated relationship between phylogenicity and drug resistance. Methodology: A total of 29 multi-drug resistant (MDR) E. coli isolates of known drug resistance genes and integron profile were selected for the present study. Triplex PCR was conducted for phylogenetic classification of these isolates into four established phylogenetic groups: A, B1, B2 and D. Statistical analysis was done to determine the association of different drug resistance genes and integrons with the phylogenetic groups. Results: Most of the isolates (44.8%) belonged to phylogenetic group A followed by group B2 and D (24.1% each) and group B1 (6.9%). Conclusions: There is a definitive relationship between drug resistance and various phylogenetic groups of E. coli infecting wounds. A shift towards phylogenetic group A might be observed with an increasing drug resistance profile.

Background: Infections caused by typhoidal salmonellae are an important public health concern in Pakistan. Inappropriate and injudicious use of fluoroquinolones has reduced their efficacy due to development of high level resistance. <br />Aim: To ascertain the current susceptibility pattern of typhoidal salmonellae thus guiding the physicians for better management of typhoid patients.<br />Materials and Methods: A study was conducted at our institution from January 2012 through December 2013 to investigate current susceptibility pattern of typhoidal salmonellae. <br />Results: Out of 200 isolates, 107 (53.5%) were identified as <em>Salmonella</em> Typhi and 93 (46.5%) as <em>Salmonella</em> Paratyphi A. Sensitivities of <em>Salmonella</em> Typhi were as follows: ampicillin (48.6%), chloramphenicol (45.8%), co-trimoxazole (40.1%), ciprofloxacin (11.2%). Sensitivities of <em>Salmonella</em> Paratyphi A were: ampicillin (80.6%), chloramphenicol (89.2%), co-trimoxazole (90.3%), and ciprofloxacin (16.1%). No resistance was detected against third generation cephalosporins. <br />Conclusions: Typhoidal salmonellae are still entirely susceptible to third generation cephalosporins in our setting. Marked rise in resistance to fluoroquinolones has reduced their empirical usage. Sensitivity of <em>Salmonella</em> Paratyphi A to conventional antityphoid drugs was encouraging.