Isolation and Detection of Drug-Resistant Bacterial Pathogens in Postoperative Wound Infections at a Tertiary Care Hospital in Saudi Arabia.

Background: Surgical site infections (SSIs), especially when caused by multidrug-resistant (MDR) bacteria, are a major healthcare concern worldwide. For optimal treatment and prevention of antimicrobial resistance, it is important for clinicians to be aware of local drug-resistant bacterial pathogens that cause SSIs. Objective: To determine the frequency patterns of drug-resistant bacterial strains causing SSIs at a tertiary care hospital in Saudi Arabia. Methods: This retrospective study was conducted at the Microbiology laboratory of Al-Noor Specialist Hospital, Makkah, Saudi Arabia, and included wound swab samples from all cases of SSI between January 01, 2017, and December 31, 2021. The swabs were processed for the identification of bacterial strains and their resistance pattern to antibiotics according to the Clinical and Laboratory Standards Institute. Results: A total of 5409 wound swabs were analyzed, of which 3604 samples (66.6%) were from male. Most samples were from the Department of Surgery (43.3%). A total of 14 bacterial strains were isolated, of which 9 were Gram-negative bacteria. The most common isolates were Klebsiella pneumoniae, followed by Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and vancomycin-resistant S. aureus (VRSA). In terms of MDR in 2021, the highest rate of carbapenem-resistance was in A. baumannii (97%). MDR was as follows: A. baumannii, 97%; K. pneumoniae, 81%; E. coli, 71%; MRSA, 60%; P. aeruginosa, 33%; VRE, 22%; and VRSA, 2%. Conclusion: This study showed that in the city of Makkah, Saudi Arabia, the rates of MDR bacteria are high, with the majority being Gram-negative.

Antimicrobial Resistance Pattern of Pseudomonas aeruginosa: An 11-Year Experience in a Tertiary Care Hospital in Makkah, Saudi Arabia.

Purpose: Pseudomonas aeruginosa (P. aeruginosa) is a common causative pathogen in healthcare settings and displays increasing levels of resistance to common antimicrobial drugs. Its capacity to resist has been reported in multiple locations across the world. This study evaluates current levels of antibiotic resistance and seeks to understand antibiotic resistance patterns in the context of the clinical isolates of P. aeruginosa. Methods: All clinical isolates were cultured at 37 °C for 24 h in different media: blood sheep agar, McConkey agar, and cystine-lactose-electrolyte-deficient agar (CLED), bacterial identification and antibiotic susceptibility patterns were determined using the Vitek-2 (bioMérieux) automated system. Results: In total, there were 61,029 patient specimens, of which 5534 were identified as non-duplicated P. aeruginosa clinical isolates, most being from males aged over 60 years. The research findings revealed that the maximum antibiotic resistance associated with P. aeruginosa isolates was found in colistin (97%), which was followed by piperacillin/tazobactam (75.8%). The maximum resistance rates in P. aeruginosa isolates were found in relation to cefepime (42.7%,) which was followed by ciprofloxacin (34.3%). Conclusion: The antibiotic resistance rate during the first six years of the research period was notably higher than in the last years, due to the application of infection control protocols and strict policies to control antibiotic prescriptions in all Saudi hospitals.

Essential Oil Analysis and Antimicrobial Evaluation of Three Aromatic Plant Species Growing in Saudi Arabia.

Arabian flora is a rich source of bioactive compounds. In this study, we investigated three aromatic plant species with the aim of finding valuable sources of antimicrobial agents against common pathogenic microorganisms. We focused especially on microorganisms, which cause outbreaks of infectious disease during mass gatherings and pilgrimages season in Saudi Arabia. The essential oils of three aromatic plant species were hydrodistilled from flowering aerial parts of Lavandula pubescens Decne. and Pulicaria incisa subsp. candolleana E.Gamal-Eldin, and from leaves, stems, ripe and unripe fruits of Juniperus procera Hochst. Ex Endl. They were subsequently analyzed by gas chromatography-mass spectrometry (GC-MS). The main constituents of L. pubescens were found to be carvacrol (55.7%), methyl carvacrol (13.4%), and ß-bisabolene (9.1%). P. incisa subsp. Candolleana essential oil was rich in linalool (33.0%), chrysanthenone (10.3%), eugenol (8.9%), and cis-chrysanthenol (8.0%); the major components of J. procera essential oil were α-pinene (31.3-62.5%) and δ-3-carene (7.3-30.3%). These essential oils were tested against thirteen American Type Culture Collection (ATCC) strains of Gram-positive and Gram-negative bacteria using the agar diffusion assay. The only effective essential oil was that of L. pubescens and the most sensitive strains were Acinetobacter baumannii, Salmonella typhimurium, Shigella sonnei, Enterococcus faecalis and Staphylococcus epidermidis. Carvacrol, the major constituent of L. pubescens, was tested on these strains and was compared with vancomycin, amikacin, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays of L. pubescens essential oil and carvacrol revealed that Gram-negative strains were more susceptible than the Gram-positive ones.

In vitro inhibitory analysis of consensus siRNAs against NS3 gene of hepatitis C virus 1a genotype.

OBJECTIVE: To explore inhibitory effects of genome-specific, chemically synthesized siRNAs (small interference RNA) against NS3 gene of hepatitis C virus (HCV) 1a genotype in stable Huh-7 (human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells. METHODS: Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin (G418) selection. The cell clones resistant to 1000 µg antibiotic concentration (G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR. RESULTS: RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested (50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24 (80%, P = 0.013) and 48 h (75%, P = 0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70% (P < 0.05) viral RNA reduction as compared to NS3-is33, which showed a 64% (P < 0.05) decrease in viral copy number. siRNA synergism (NS3-is33 + NS3-is44) decreased viral load by 84% (P < 0.05) as compared to individual inhibition by each siRNA (i.e., 64%-70% (P < 0.05)) in serum-inoculated cells. Synthetic siRNAs mixture (NS5B-is88 + NS3-is33) targeting different region of HCV genome (NS5B and NS3) also decreased HCV viral load by 85% (P < 0.05) as compared to siRNA inhibitory effects alone (70% and 64% respectively, P < 0.05). CONCLUSIONS: siRNAs directed against NS3 gene significantly decreased mRNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.

CapA, an autotransporter protein of Campylobacter jejuni, mediates association with human epithelial cells and colonization of the chicken gut.

Two putative autotransporter proteins, CapA and CapB, were identified in silico from the genome sequence of Campylobacter jejuni NCTC11168. The genes encoding each protein contain homopolymeric tracts, suggestive of phase variation mediated by a slipped-strand mispairing mechanism; in each case the gene sequence contained frameshifts at these positions. The C-terminal two-thirds of the two genes, as well as a portion of the predicted signal peptides, were identical; the remaining N-terminal portions were gene specific. Both genes were cloned and expressed; recombinant polypeptides were purified and used to raise rabbit polyclonal monospecific antisera. Using immunoblotting, expression of the ca.116-kDa CapA protein was demonstrated for in vitro-grown cells of strain NCTC11168, for 4 out of 11 recent human fecal isolates, and for 2 out of 8 sequence-typed strains examined. Expression of CapB was not detected for any of the strains tested. Surface localization of CapA was demonstrated by subcellular fractionation and immunogold electron microscopy. Export of CapA was inhibited by globomycin, reinforcing the bioinformatic prediction that the protein is a lipoprotein. A capA insertion mutant had a significantly reduced capacity for association with and invasion of Caco-2 cells and failed to colonize and persist in chickens, indicating that CapA plays a role in host association and colonization by Campylobacter. In view of this demonstrated role, we propose that CapA stands for Campylobacter adhesion protein A.