Efflux pump inhibitors may inhibit the major AcrAB-TolC in Salmonella efflux systems which are the major efflux pumps responsible for multidrug resistance in Gram-negative clinical isolates.

The presented results suggest the potential application of EOs against infections, caused by biofilm-producing K. pneumoniae, to prevent biofilm formation or decrease their resistance threshold. Moreover, the combination of EOs with ciprofloxacin minimizes the antibiotic concentration used and accordingly the potential accompanying toxic side effects.

Background: Carbapenem antibiotics consider the primary treatment choice for serious Pseudomonas aeruginosa infection. Hence, the evolution of carbapenem resistance mediated by acquiring genes encoding class b enzymes is of global concern. The purpose of this article research is to explore the prevalence, drug resistance profiles, and metallo-βlactamases (MβLs) production in extensively drug-resistant carbapenem-resistant P. aeruginosa (XDR-CRPA). Methods: P. aeruginosa isolates were collected and identified according to conventional methods. Antibiotic resistance patterns were determined by single disk diffusion. Minimum inhibitory concentrations (MICs) of (imipenem, meropenem, ceftazidime, piperacillin/tazobactam, levofloxacin, and gentamicin) were determined for CRPA. A subset of the isolates collection consisting of the XDR-CRPA with the highest MICs to imipenem and meropenem were selected for the phenotypic screening of carbapenemases and MβLs production capability using the modified carbapenem inactivation (mCIM) and imipenem-EDTA combined disk (MβL-CD) methods, respectively. Then, molecular analysis, including identification by the specific primer of 16S rRNA and detection of MβL genes using polymerase chain reaction (PCR) was performed to the XDR selected isolates. Results: Among 100 P. aeruginosa isolated throughout this period, 59% exhibited reduced susceptibility rates to carbapenems. A total of 20.3% and 57% of CRPA isolates were MDR and XDR, respectively. MIC values of the CRPA revealed that these isolates exhibited high MIC 50 and MIC 90 to the six selected antibiotics. The findings of the (mCIM) assay displayed identical concordance results with the MβL-CD. Molecular investigation technique assured that 10 (90.9%) and 2 (18.1%) of the 11 XDR selected isolates are positive for bla NDM-1 and bla VIM-1 genes, respectively. Polymyxin B and colistin followed by aztreonam were the most effective antibiotics used for curing infections caused by XDR Pseudomonas aeruginosa. Conclusion: The prevalence of high XDR-CRPA in our study is a critical problem. Our present study found that the bla NDM-1 was present at a significant frequency among the selected XDR isolates, highlighting the need for establishing strict antimicrobial policies to avoid the prompt spread of these isolates.

The emergence of multi-drug-resistant (MDR) pathogenic bacteria is considered as a global problem. The aim of this study was to evaluate the antimicrobial inhibitory effects of the oily aqueous extract of Moringa peregrina Forssk against MDR clinical Salmonella enterica isolates. Four MDR S. enterica isolates were proved to have a gene mutation in amino acids codon 83 and 87 of gyrA and 67, 76 and 80 of parC gene by polymerase chain reaction (PCR) amplification and sequencing. The active components of M. pregrina extract were purified using GLC and TLC techniques and by using IR, NMR and mass spectra. The M. peregrina Forssk extract effect on bacterial cells was determined using scanning and transmission electron microscopies. Results demonstrated that M. peregrina Forssk have an excellent inhibitory effect against 34 MDR S. enterica isolates with different minimum inhibitory concentration (MIC) (109.37-437.5 mg/mL). The active component was identified as oleic acid-3 hydroxy propyl ester. The main abnormalities of Salmonella cells were observeddestruction in the cell wall that led to a reduction of protoplast besides, disruption of cytoplasmic membranes and, consequently, loss in their metabolic functions and death. This is the first report that deeply highlights the antimicrobial activity of M. peregrina Forssk against MDR clinical S. enterica isolates.

Determination of the rHLB of Garlic and Eruca oils allows the ease of preparation of stable, consistent, and non-irritant cream.