Multiple drug resistance patterns in various phylogenetic groups of uropathogenic E. coli isolated from Faisalabad region of Pakistan

The objective of this work was the phylogenetic characterization of local clinical isolates of uropathogenic E. coli with respect to drug resistance. A total of 59 uropathogenic E. coli responsible for community acquired urinary tract infections were included in this study. A triplex PCR was employed to segregate each isolate into four different phylogenetic groups (A, B1, B2 and D). Drug resistance was evaluated by disc diffusion method. The drugs used were ampicillin, aztreonam, cefixime, cefoperazone, ceftriaxone, cephradine among â-lactam group; amikacin, gentamicin, and streptomycin among aminoglycosides; nalidixic acid and ciprofloxacin from quinolones; trimethoprim-sulfomethoxazole, and tetracycline. Among 59 uropathogenic E. coli isolates majority belonged to phylogenetic group B2 (50 percent) where as 19 percent each belonged to groups A and B1, and 12 percent to group D. All the isolates were multiple drug resistant (MDR). Most effective drugs against Group A, B1, and B2 were gentamicin, amikacin and cefixime; ceftriaxone and quinolones; and ceftriaxone and amikacin, respectively. Group D isolates were found to be highly resistant to all drugs. Our results have shown emergence of MDR isolates among uropathogenic E. coli with dominance of phylogenetic group B2. However, it was found that group D isolates were though less frequent, more drug resistant as compared with group B2. Groups A and B1 were relatively uncommon. Amikacin, ceftriaxone and gentamicin were the most effective drugs in general.

Differentiation of common gram negative pathogens by PCR- ribotyping

Gram negative bacteria especially members of family Enterobacteriaceae are among the most frequently isolated organisms from the clinical specimens. Rapid diagnosis of the pathogen in a clinical sample is always very important. Conventional methods are time-consuming. Among molecular techniques, PCR is very useful but unless very specific primers are used, non-specific amplifications are a problem. PCR-ribotying is a technique that gives very specific multiple bands by use of a single primer set. This study was designed to establish patterns for five common pathogens of Enterobacteriaceae, namely Escherichia coli, Salmonella enterica serovar Typhi [Salmonella Typhi], Proteus vulgaris, Klebsiella aerogenes, and Cirtobacter freundii along with another very common and problematic gram negative pathogen Pseudomonas aeruginosa. Each species gave a specific ribotyping pattern. Escherichia coli gave four amplification products of 1200, 850, 800, and 700 bps. Four amplification products of different sizes were also observed in Citrobacter freundii [3000, 850, 700, and 580 bps], Proteus vulgaris [900, 800, 750 and 700 bps], and Klebisella aerogenes [3000, 870, 700 and 520 bps]. More discrimination with five amplification products was seen in Salmonella Typhi [3000, 1200, 900, 850, and 700 bps]. On the other side of spectrum was Pseudomonas aeruginosa only a single amplification product of 750 bps was observed. PCR-ribotyping can very efficiently and specifically differentiate between opportunistic gram negative human pathogens