Phenotypic and Molecular Characterization of CTX-M Type B-Lactamases in Gram Negative Bacterial Strains Isolated from Hospitals, Lahore, Pakistan.

One of the principal mechanisms that contribute resistance to antibiotics is the production of extended spectrum beta lactamase (ESBL) in Gram negative bacteria. In the present study, molecular methods were used to evaluate the prevalence of the extended-spectrum beta-lactamase (ESBL)-encoding CTX-M gene among Gram negative bacterial strains. In total, 148 clinical samples were collected from different tertiary care hospitals of Lahore, Pakistan. Disc synergy diffusion method was used to detect the presence of ESBL production. Moreover, antibiotic resistance patterns and molecular detection of bla CTX-M ESBLs, were also studied. The pathogens isolated from the 148 samples included Escherichia coli (43%) followed by Klebsiella sp. (28%), Proteus sp. (18%) and Pseudomonas sp. (11%). In all 148 strains, 95 (64%) were ESBL producers while 53 (36%) were non ESBL producers. The strains which were phenotypically ESBL producers, bla CTX-M were found in 46% E. coli strains, while 50% Klebsiella sp. were harboring the gene. A high resistance rate was observed against cephalosporins (cefopodoxime 67%, cefoperazone 73%, cephalexin 63% sparaxin 61%). Lower resistance was observed against meropenem among all isolated bacterial strains. Genotypic detection of bla CTX-M genes by PCR revealed 46% of E. coli and 50% of Klebsiella strains harbored bla CTX-M gene. The present study showed that ESBLs producers were resistant to commonly used antibiotics. Similarly, bla CTX-M ESBL production is more prevalent in our clinical isolates.

Medicinal Perspective of Antibacterial Bioactive Agents in Earthworms (Clitellata, Annelida): A Comprehensive Review.

Humoral practice is a fundamental natural biological phenomenon in earthworm defensive system which protects them from infectious bacteria and irritating agents by different mechanisms. The defensive system of earthworms is highly complicated because they lack antibodies in their blood circulatory system but their body extracts and coelomic fluid comprise of different bioactive agents (i.e. peptides and proteins) that defend these worms. There are various groups of bioactive agents such as proteases (name depends on proteins/peptide function or formal earthworm species name), metabolites (total 59 metabolites found in Eisenia fetida), metal binding proteins (2 proteins such as Ca2+ binding calmodulin and metallothionein), active proteins (include lysozyme, lysenin and eiseniapore etc.), antimicrobial peptides (antibacterial vermi-peptides family (AVPF), antimicrobial peptide I (PP-I), coelomic cytolytic factor (CCF, CCF-I and CCF like protein), fetidin, lysenin, lumbricin (lumbricin I, lumbricin PG, and lumbricusin), organic acids (fatty acids, succinic acids, and lauric acid) and other organic compounds (such as purine and vitamin D). The presence of above mentioned molecules confer therapeutic potential that affect energy intake and involve in decreasing oxidative stress, metabolic disturbances and pro-inflammatory conditions. The future perspectives of earthworm bioactive compounds are concerned with the development of provisional standards, purification and classification for utilizations in pharma industry.

Honey Potential as Antibiofilm, Antiquorum Sensing and Dispersal Agent against Multispecies Bacterial Biofilm.

This study is first to test Pakistani honey bees, Apis dorsata and A. cerana honey samples as anti biofilm, anti quorum sensing (QS) and biofilm dispersal agents honey against multispecies biofilm of bacteria (obtained from obese patients). Briefly, five previously identified isolates Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Morganella morganii and Klebsiella pneumoniae (MT448672-MT448676) were selected. Antibiogram study of all five isolates was tested against three antibiotics viz., erythromycin (20 µg/mL), lincomycin (100 µg/mL) and rifampicin (100 µg/mL). In order to form multispecies biofilm, identified bacteria were grown in batch culture by mixing equal volumes (OD590nm = 0.1) of 2, 3 and 5 bacterial isolates. In total 11 groups (g1-g11) were made. Crystal violet (CV) staining method was used to evaluate the antibiofilm potential and biofilm dispersal potential of both honey samples. QS inhibition in P. aeruginosa was measured following culture supernatant method. Antibiogram study showed significant (p < 0.05) resistance by P. aeruginosa against tested antibiotics. E. coli, M. morganii and K. pneumoniae were significantly susceptible to erythromycin and S. aureus to lincomycin. Both honey samples at 2% and 5% concentrations showed significant (p < 0.05) inhibition potential of multispecies biofilm by all test groups (g1-g11). Though A. dorsata honey significantly inhibited biofilm formation at 2 and 5% against all groups but 2% concentration was highly significant against g2-g4 groups. Regarding A. cerana honey, 2% concentration was significantly effective against g1, g4-g7 and g9-g11 groups. Both honey samples significantly inhibited QS at 2 and 5%. The 5% concentration of A. dorsata honey significantly dispersed biofilm by all groups compared to 2% which showed dispersal potential only by g2 and g3 groups. Accordingly, honey samples showed significant antibiofilm, anti-QS and biofilm dispersal potentials thus can be considered as good alternative to antibiotics.