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Introduction: Ampicillinase C beta-lactamase-producing organisms are often resistant to multiple antimicrobial agents, and therapeutic options against these pathogens are limited. Limited information is available regarding Ampicillinase C beta-lactamase producers. The aim of this study was to find out the prevalence of Ampicillinase C beta-lactamase producers among isolates of Enterobacteriaceae in a tertiary care centre. Methods: A descriptive cross-sectional study was carried out in the Clinical Microbiology Laboratory of a tertiary care centre from May 2021 to October 2021. Ethical approval was received from the Institutional Review Committee (Reference number: 044-077/078). Isolates of Enterobacteriaceae from various clinical samples were collected by convenience sampling. Ampicillinase C screening for beta-lactamase producers among the Enterobacteriaceae isolates was done using cefoxitin (30 μg) disc. Detection of Ampicillinase C beta-lactamase producers among the screen-positive isolates was done by cefoxitin-cloxacillin double-disc synergy test. An increase in the zone size of ≥4 mm was considered as Ampicillinase C beta-lactamase producers. Point estimate and 95% Confidence Interval were calculated. Results: Among the total 481 isolates of Enterobacteriaceae, 49 (10.19%) (7.50-12.90, 95 % Confidence Interval) were detected as Ampicillinase C beta-lactamase producers among isolates of Enterobacteriaceae. Conclusions: The prevalence of Ampicillinase C beta-lactamase producers was lower than in other studies done in similar settings. Meropenem could be a drug of choice for the treatment of infections due to Ampicillinase C beta-lactamase-producing gram-negative bacteria.

Summary: Silver nanoparticles (Ag NPs) are used in sterilizing nanomaterials, medical products, textiles, food storage bags, and personal care products. Ag NPs exhibited significant antibacterial activity due to the sustained release of free Ag. Flavokawain B (FKB) is a natural chalcone extracted from the roots of the kava-kava plant Piper methysticum. In this study, Ag NPs were synthesized by the chemical method using hydrazine hydrate and poly (vinyl alcohol) as reducing and stabilizing agents, respectively. FKB-loaded Ag NPs showed a red shift and were positioned at 421 nm, indicating Ag NPs presence. The FTIR spectrum confirmed the presence of the aromatic compound's functional groups (at different absorption bands). The XRD pattern indicated the crystalline nature of the loaded Ag NPs with face-centered cubic (fcc) Ag crystals. SEM image revealed the crystalline nature of FKB-loaded Ag NPs. FESEM image revealed the loading of Ag NPs on the clear and flat surface of FKB, and a spherical shape of Ag NPs with an average size of 60 nm was obtained. The minimum inhibitory concentration (MIC) of AgFKB against Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa was found to be 100 µg/mL. However, 100 µg/mL of FKB discs did not show any inhibition zone in the activity. These findings indicated the improved antibacterial activity of FKB-loaded Ag NPs (Ag-FKB). [ABSTRACT FROM AUTHOR]

Truly miraculous medications and antibiotics have helped save untold millions of lives. Antibiotic resistance, however, is a significant issue related to health that jeopardizes the effectiveness of antibiotics and could harm everyone's health. Bacteria, not humans or animals, become antibiotic-resistant. Bacteria use quorum-sensing communication routes to manage an assortment of physiological exercises. Quorum sensing is significant for appropriate biofilm development. Antibiotic resistance occurs when bacteria establish a biofilm on a surface, shielding them from the effects of infection-fighting drugs. Acylated homoserine lactones are used as autoinducers by gram-negative microscopic organisms to impart. However, antibiotic resistance among ocular pathogens is increasing worldwide. Bacteria are a significant contributor to ocular infections around the world. Gram-negative microscopic organisms are dangerous to ophthalmic tissues. This review highlights the use of elective drug targets and treatments, for example, combinational treatment, to vanquish antibiotic-resistant bacteria. Also, it briefly portrays anti-biotic resistance brought about by gram-negative bacteria and approaches to overcome resistance with the help of quorum sensing inhibitors and nanotechnology as a promising medication conveyance approach to give insurance of anti-microbials and improve pathways for the administration of inhibitors of quorum sensing with a blend of anti-microbials to explicit target destinations and penetration through biofilms for treatment of ocular infections. It centres on the methodologies to sidestep the confinements of ocular anti-biotic delivery with new visual innovation., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Abstract Background and Objective: The spread of drug resistance in bacteria have prompted researchers to seek suitable alternative for antimicrobial drugs among various medicinal plants and nanoparticles. The aim of this study was to evaluate the effect of silver nanoparticles alone and in combination with methanol extract of Zataria multiflora on five Gram-positive and Gram-negative bacteria. Methods: Different concentrations of the nanoparticles and extract alone or in combination with each other were tested against the bacteria, using well diffusion method. Three concentration levels (lowest, average and highest) were prepared form the nanoparticles and the extract for the combination, and finally nine different combinations were prepared. Results: The extract and nanoparticles showed inhibitory effects against all the tested bacteria. The maximum diameter of growth inhibition zone in the presence of the extract and nanoparticles were observed in Streptococcus pyogenes (35.6mm) and methicillin-resistant Staphylococcus aureus (20.6mm), respectively. The maximum diameter of growth inhibition zone for the combination was measured in S. pyogenes (31mm). Conclusion: The combination of low concentrations of the plant extract and nanoparticles are more effective against bacteria, but the combination of their high concentrations reduce the antibacterial effects in some cases.

We assessed in this study the total airborne bacteria (TAB), gram-negative bacteria (GNB), and endotoxin (ET) concentrations in three Korean university laboratories and two hospital diagnostic laboratories categorized as biosafety level 1 (BL 1) or biosafety level 2 (BL 2). We also investigated the concentrations of TAB, GNB, and ET relative to the performance results of biosafety cabinets (BSCs). TAB and GNB were incubated, and ET was analyzed using the kineticLimulus amebocyte lysateassay. A total of 246 (TAB = 95, GNB = 95, ET = 56) air samples were collected from nine laboratories. TAB, GNB, and ET concentrations were significantly higher in BL 1 laboratories and in laboratories that failed the BSC performance test compared to BL 2 laboratories and laboratories that passed the BSC performance test. Correlation coefficients were calculated to determine the relationships between TAB, GNB, and ET, and it was found that TAB significantly correlated with GNB (r = 0.35,p< .01) and ET (r = 0.29,p< .01). Careful attention needs to be paid to BL 1 laboratories, and BSCs should be managed on a regular basis to improve the air quality of university and hospital laboratories. [ABSTRACT FROM AUTHOR]

RND (Resistance-Nodulation-Division) family transporters have a vital role in both intrinsic and acquired multi-drug resistance in Gram-negative bacteria. It is important to find a conserved domain in the RND family between different pathogenic bacteria for diagnostic and therapeutic purpose. Total sequences of three-component system RND efflux pumps were retrieved from NCBI nucleotide and protein database and were subjected to conservation and variation analysis using the multiple sequence alignment feature of the CLC workbench. The phylogenetic tree for main transporters was drawn and the three-dimensional structure was also evaluated. From the sequence conservation analysis, highly conserved residues with 282 base pair (94 amino acid) long were identified. The location of the highly conserved domain is positioned in the domain 1 crystallographic structure of AcrB Escherichia coli and MexB Pseudomonas aeruginosa. The main transporter component phylogenetic tree shows the clusters of different genotypes and their evolutionary association.  Each of three components of RND proteins is crucial for drug efflux, and the absence of even one component makes the entire complex totally nonfunctional. Therefore, this highly conserved region can be used to disable the RND multidrug efflux pumps. In addition, this highly conserved can also be used for diagnostic aspects.