The study focuses on the fabrication of silver nanoparticles (Ag NPs) using aqueous extracts of Allium sativum as reducing agents. Silver ion becomes a good carrier of bioactive compounds of Allium sativum, so their biochemical potential such as total phenolic and flavonoids were evaluated. Results showed that as a concentration increases TPC and TFC were also increased. Similar to their secondary metabolite, scavenging potential of Ag NPs of Allium sativum was also monitored. Green synthesized Ag NPs exhibited significant antibacterial activity 24±2.6, 22±1.4, 19±2.7 and 20±3.17 against B. subtilis, S. aureus, E. coli and P. multocida bacterial strains respectively. Moreover, Ag NPs of garlic did not show any mutagenicity against mutant strain of S. typhimurium TA98 & TA100. Brine shrimp lethality assay (BSLA) showed their dose dependent effect. Finally, green synthesized Ag NPs of garlic presented anti-proliferative effect against HEPG2 cell line.

Extended-spectrum β-lactamases (ESBL) give rise to resistance against penicillin and cephalosporin antibiotics in multiple bacterial species. The present study was conducted to map genetic determinants and related attributes of ESBL-producing bacteria in three wild aquatic bird species and chickens at the “Trimmu Barrage” in district Jhang, Punjab province, Pakistan. To study the prevalence of ESBL-producing bacteria, a total of 280 representative samples were collected from wild bird species; cattle egrets (Bubulcus ibis), little egrets (Egretta garzetta) and common teals (Anas crecca) as well as from indigenous chickens (Gallus gallus domesticus) originating from a local wet market. The isolates were confirmed as ESBL producers using a double disc synergy test (DDST) and bacterial species were identified using API-20E and 20NE strips. A polymerase chain reaction (PCR) was used to detect ESBL genetic determinants and for genus identification via 16S rRNA gene amplification. A phenotypic antimicrobial susceptibility test was performed for ESBL-producing isolates against 12 clinically relevant antibiotics using the Kirby–Bauer disk diffusion susceptibility test. A phylogenetic tree was constructed for the sequence data obtained in this study and comparative sequence data obtained from GenBank. The overall prevalence of ESBL-producing bacteria was 34.64% (97/280). The highest percentage (44.28%; 31/70) of ESBL-producing bacteria was recovered from chickens (Gallus gallus domesticus), followed by little egrets (Egretta garzetta) (41.43%; 29/70), common teal (Anas crecca) (28.57%; 20/70) and cattle egrets (Bubulcus ibis) (24.28%; 17/70). Five different ESBL-producing bacteria were identified biochemically and confirmed via 16S rRNA gene sequencing, which included Escherichia coli (72; 74.23%), Enterobacter cloacae (11; 11.34%), Klebsiella pneumoniae (8; 8.25%), Salmonella enterica (4; 4.12%) and Pseudomonas aeruginosa (2; 2.06%). Based on PCR, the frequency of obtained ESBL genes in 97 isolates was bla_CTX-M (51.55%), bla_TEM (20.62%), bla_OXA (6.18%) and bla_SHV (2.06%). In addition, gene combinations bla_CTX-M + bla_TEM, bla_TEM + bla_OXA and bla_CTX-M + bla_SHV were also detected in 16.49%, 2.06% and 1.03% of isolates, respectively. The ESBL gene variation was significant (p = 0.02) in different bacterial species while non-significant in relation to different bird species (p = 0.85). Phylogenetic analysis of amino acid sequence data confirmed the existence of CTX-M-15 and TEM betalactamases. The average susceptibility of the antibiotics panel used was lowest for both Klebsiella pneumoniae (62.5% ± 24.42) and Salmonella enterica (62.5% ± 31.08) as compared to Enterobacter cloacae (65.90% ± 21.62), Pseudomonas aeruginosa (70.83% ± 33.42) and Escherichia coli (73.83% ± 26.19). This study provides insight into the role of aquatic wild birds as reservoirs of ESBL-producing bacteria at Trimmu Barrage, Punjab, Pakistan. Hence, active bio-surveillance and environment preservation actions are necessitated to curb antimicrobial resistance.