Antibacterial efficacy of silver nanoparticles (AgNPs) against metallo-ß-lactamase and extended spectrum ß-lactamase producing clinically procured isolates of Pseudomonas aeruginosa.

Resistance to carbapenems is a global threat, especially in developing countries with limited health resources. Prevalence, antibiogram, PCR detection of antibiotic resistance genes, and potency of Silver Nanoparticles (AgNPs) against multidrug-resistant (MDR) Pseudomonas aeruginosa were studied. Kirby-Bauer disc method and PCR were used to study antibiogram and drug resistance genes respectively in 255 isolates of Pseudomonas aeruginosa obtained from a tertiary care hospital. Silver nitrate (AgNO3) precursor salts were reacted with Aspergillus flavus culture filtrate to trigger the extracellular mycosynthesis of AgNPs. Mycosynthesis was first monitored regularly by visible ultraviolet spectroscopy that recorded AgNP peaks of approximately 400-470 nm. Confirmation by Transmission electron micrographs provided confirmation of AgNPs formed within a range of 5-30 nm. Individual and combined antibacterial activity of ten antibiotics and AgNPs was analyzed. Pearson correlation coefficients (r) were calculated for phenotypic and genotypic multidrug resistance. Data were evaluated using SPSS version 20. p-value < 0.05 was considered statistically significant. 61.5% were carbapenemase producers (p < 0.01). The recorded frequency of blaIMP-1, blaSHV, blaVIM, blaOXA, and blaTEM were 13%, 32%, 15%, 21%, and 43%, respectively. The reducing order of antimicrobial activity of antibiotics and AgNPs was piperacillin/tazobactam + AgNPs (31 mm), cefoxitin + AgNPs (30 mm) > amikacin + AgNPs (25 mm) > aztreonam + AgNPs (23 mm) > meropenem + AgNPs (22 mm) > imipenem + AgNPs (20 mm) > gentamycin + AgNPs (17 mm) > ciprofloxacin + AgNPs (16 mm) > cefoperazone/sulbactam + AgNPs (14 mm) ≥ ceftazidime + AgNPs (14 mm). The conjugated effect of AgNPs plus antibiotics showed a 0.15-3.51 (average of 2.09) fold-area augmentation of antimicrobial activity. AgNPs conjugated with antibiotics effectively inhibited MDR Pseudomonas aeruginosa. To the best of our understanding, this is an inaugural report from Punjab Pakistan enlisting co-expression of Metallo-ß-lactamases, extended-spectrum ß-lactamases, and AmpC-ß-lactamase plus activity of antibiotic-AgNPs.

Successful outcome using Tocilizumab in COVID-19 pneumonia with respiratory failure on a ward level.

We describe the case of a 40-year-old man of Asian ethnicity, who presented with one week history of shortness of breath, productive cough, intermittent hemoptysis, temperature, and systemic symptoms. He had a positive nasopharyngeal swab for SARS-CoV-2, standard COVID panel admission blood tests, a chest X-ray and a CT Pulmonary Angiogram. Significant bilateral infiltrates and no pulmonary embolism were identified. The patient received standard COVID-19 treatment. After 36 hours, he deteriorated requiring initiation of non-invasive ventilatory (NIV) support. In the context of worsening clinical status, the patient received Tocilizumab as a single dose with good clinical response. Early Tocilizumab intervention in appropriately selected patients should improve the outcome and length of hospitalization in COVID-19 pneumonia. It can be used as an intensive therapy unit sparing agent allowing management of critically ill patients on a ward-based level. This may further contribute to prevention of intensive therapy unit related complications and increased mortality.

Epidemiology and high incidence of metallo-ß-lactamase and AmpC-ß-lactamases in nosocomial Pseudomonas aeruginosa.

OBJECTIVES: Isolates producing metallo-ß-lactamase (MBL) have a significant impact on therapeutic and diagnostic layouts, plus their increased frequency has been reported globally. Determination of incidence of clinical isolates of Pseudomonas aeruginosa that are capable of producing MBL and AmpC-ß-lactamases making them resistant to imipenem and cefoxitin. MATERIALS AND METHODS: Out of 1159 collected samples of urine, wound swabs, blood, tissue, and pus, the isolation rate of P. aeruginosa in the period of March 2020 to February 2021 was 22.0% (255/1159). Bacterial strains that were resistant towards imipenem were further processed for detecting the ß-lactamase group of genes followed by statistical analysis of risk factors done based on clinical sample, gender, plus department of sample collection. RESULTS: The percentage of resistance against imipenem was found to be 53%. Out of 135 strains, phenotypic tests revealed MBLs incidence to be 61.5% by combination disc test and 81.5% by Modified Hodge test (MHT). Frequencies of blaIMP-1, blaVIM, blaSHV, blaTEM, and blaOXA genes were calculated to be 13%, 15%, 32%, 43%, and 21%, respectively. Co-expressions of blaMBLs (blaVIM and blaIMP-1) plus blaESBL (blaSHV, blaOXA, blaTEM) were detected using simplex and multiplex PCR. blaTEM, blaSHV, and blaOXA co-existed in 7.5% of clinical isolates. 5.5% of the isolates exhibited simultaneous expression of MBL/ESBL genes. 15% of the isolates resistant to cefoxitin were positive for the blaAmpC gene (17/114). CONCLUSION: This is a pioneer report from Pakistan that concomitantly presents expression of blaVIM and blaIMP-1 with blaTEM, blaOXA, blaSHV, and blaAmpC in isolates of P. aeruginosa.