Virulence genes distributed among Staphylococcus aureus causing wound infections and their correlation to antibiotic resistance.

BACKGROUND: Staphylococcus aureus causes many human infections, including wound infections, and its pathogenicity is mainly influenced by several virulence factors. AIM: This study aimed to detect virulence genes (hla, sea, icaA, and fnbA) in S. aureus isolated from different wound infections among Egyptian patients admitted to Minia University Hospital. This study also aimed to investigate the prevalence of these genes in methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA), and vancomycin-resistant S. aureus isolates and the resistance and sensitivity to different antibiotic classes. METHODS: A cross-sectional study was carried out from November 2019 to September 2021. Standard biochemical and microbiological tests revealed 59 S. aureus isolates. The Kirby-Bauer disc diffusion method was used to determine antibiotic susceptibility. DNA was extracted using a DNA extraction kit, and polymerase chain reaction was used to amplify all genes. RESULTS: A total of 59 S. aureus isolates were detected from 51 wound samples. MRSA isolates accounted for 91.5%, whereas MSSA isolates accounted for 8.5%. The multidrug resistance (MDR) percentage in S. aureus isolates was 54.2%. S. aureus showed high sensitivity pattern against vancomycin, linezolid, and chloramphenicol. However, a high resistance pattern was observed against oxacillin and piperacillin. sea was the most predominant gene (72.9%), followed by icaA (49.2%), hla (37.3%), and fnbA (13.6%). sea was the commonest virulence gene among MRSA isolates (72.2%), and a significant difference in the distribution of icaA was found. However, sea and icaA were the commonest genes among MSSA isolates (79.9%). The highest distribution of sea was found among ciprofloxacin-resistant isolates (95.2%). CONCLUSION: The incidence of infections caused by MDR S. aureus significantly increased with MRSA prevalence. sea is the most predominant virulence factor among antibiotic-resistant strains with a significant correlation to piperacillin, gentamicin, and levofloxacin.

Influence of selected non-antibiotic pharmaceuticals on antibiotic resistance gene transfer in Escherichia coli.

BACKGROUND: Antibiotic resistance genes (ARGs) transfer rapidly among bacterial species all over the world contributing to the aggravation of antibiotic resistance crisis. Antibiotics at sub-inhibitory concentration induce horizontal gene transfer (HRT) between bacteria, especially through conjugation. The role of common non-antibiotic pharmaceuticals in the market in disseminating antibiotic resistance is not well studied. OBJECTIVES: In this work, we indicated the effect of some commonly used non-antibiotic pharmaceuticals including antiemetic (metoclopramide HCl) and antispasmodics (hyoscine butyl bromide and tiemonium methyl sulfate) on the plasmid-mediated conjugal transfer of antibiotic resistance genes between pathogenic E. coli in the gastric intestinal tract (GIT). METHODS: Broth microdilution assay was used to test the antibacterial activity of the tested non-antibiotic pharmaceuticals. A conjugation mating system was applied in presence of the studied non-antibiotic pharmaceuticals to test their effect on conjugal transfer frequency. Plasmid extraction and PCR were performed to confirm the conjugation process. Transmission electron microscopy (TEM) was used for imaging the effect of non-antibiotic pharmaceuticals on bacterial cells. RESULTS: No antibacterial activity was reported for the used non-antibiotic pharmaceuticals. Plasmid-mediated conjugal transfer between isolates was induced by metoclopramide HCl but suppressed by hyoscine butyl bromide. Tiemonium methylsulfate slightly promoted conjugal transfer. Aggregation between cells and periplasmic bridges was clear in the case of metoclopramide HCl while in presence of hyoscine butyl bromide little affinity was observed. CONCLUSION: This study indicates the contribution of non-antibiotic pharmaceuticals to the dissemination and evolution of antibiotic resistance at the community level. Metoclopramide HCl showed an important role in the spread of antibiotic resistance.

Prevalence and resistance profile of bacteria isolated from wound infections among a group of patients in upper Egypt: a descriptive cross-sectional study.

AIM: This cross-sectional survey aimed to identify aerobic bacteria, antimicrobial resistance, and multi-drug resistance profiles of bacteria isolated from different wound infections among a group of Egyptian patients. RESULTS: Of 120 positive samples, 170 isolates were identified. Polymicrobial infections were determined in 55% of samples. The dominant Gram-positive isolated strains were Staphylococcus aureus, especially from wound infections because of accidents (71.8%). Piperacillin, methicillin, ampicillin/sulbactam, and amoxicillin/clavulanic acid were all highly resistant to S. aureus and Coagulase-negative Staphylococci. The prevalence of methicillin-resistant S. aureus in wound infections was 89.9%. S. aureus showed superior sensitivity to vancomycin (85.3%) and linezolid (81.3%). The highest prevalence of Gram-negative isolates was for Pseudomonas aeruginosa (40%), which was highly sensitive to ciprofloxacin (79.2%) and highly resistant to levofloxacin (83.3%). Several isolates revealed a multi-drug resistance profile (52.4%). The overall MDR rate of Gram-positive and Gram-negative isolates were 50% and 54.9%, respectively. CONCLUSION: The prevalence of MRSA isolated from various wound infections and MDR is a warning issue in Upper Egypt. It should implement a health education strategy and hygiene measures to prevent the spread of wound infection-causing organisms in the community.

COVID-19 awareness among a group of Egyptians and their perception toward the role of dentists in its prevention: a pilot cross-sectional survey.

AIM: The main purpose of the study is to assess the awareness of a group of Egyptians about COVID-19 infection and their perception of the role of dentists in its prevention. SUBJECTS AND METHODS: An observational cross-sectional survey included 74 participants who attended Minia University Dental Hospital, Minia City, Egypt, from 10 March to 2 April 2020. A face-to-face interview using an anonymous questionnaire was carried out in this study. The questionnaire contained 20 questions divided into three parts; the first part included the participants' baseline characteristics. The second part analyzed the participants' awareness of COVID-19 infection through ten questions. Finally, four questions outlined participants' perception of the role of dentists in preventing the spread of COVID-19. RESULTS: Overall participant awareness was adequate at 55.4%. The percentages of "good" and "poor" overall awareness scores were 40.5% and 4.1%, respectively. Most respondents' perception of dentists' role in COVID-19 prevention was poor. All baseline characteristics showed no statistically significant difference related to the participants' awareness about COVID-19 infection and its spread (p > 0.05). CONCLUSION: From the findings of the present pilot study, it can be concluded that the general population's awareness of COVID-19 infection and its route of transmission was adequate. Participants' understanding of the role of dentists in COVID-19 prevention was poor.

Virulence profiles of some Pseudomonas aeruginosa clinical isolates and their association with the suppression of Candida growth in polymicrobial infections.

Pseudomonas aeruginosa is an opportunistic pathogen that can cause a variety of diseases especially in the hospital environment. However, this pathogen also exhibits antimicrobial activity against Gram-positive bacteria and fungi. This study aimed to characterize different virulence factors, secreted metabolites and to study their role in the suppression of Candida growth. Fifteen P. aeruginosa isolates were tested for their anticandidal activity against 3 different Candida spp. by the cross-streak method. The effect on hyphae production was tested microscopically using light and scanning electron microscopy (SEM). Polymerase chain reaction was used in the detection of some virulence genes. Lipopolysaccharide profile was performed using SDS-polyacrylamide gel stained with silver. Fatty acids were analyzed by GC-MS as methyl ester derivatives. It was found that 5 P. aeruginosa isolates inhibited all tested Candida spp. (50-100% inhibition), one isolate inhibited C. glabrata only and 3 isolates showed no activity against the tested Candida spp. The P. aeruginosa isolates inhibiting all Candida spp. were positive for all virulence genes. GC-Ms analysis revealed that isolates with high anticandidal activity showed spectra for several compounds, each known for their antifungal activity in comparison to those with low or no anticandidal activity. Hence, clinical isolates of P. aeruginosa showed Candida species-specific interactions by different means, giving rise to the importance of studying microbial interaction in polymicrobial infections and their contribution to causing disease.

Prevalence of Virulence Genes and Their Association with Antimicrobial Resistance Among Pathogenic E. coli Isolated from Egyptian Patients with Different Clinical Infections.

INTRODUCTION: Escherichia (E.) coli can cause intestinal and extra-intestinal infections which ranged from mild to life-threatening infections. The severity of infection is a product of many factors including virulence properties and antimicrobial resistance. OBJECTIVES: To determine the antibiotic resistance pattern, the distribution of virulence factors and their association with one another and with some selected resistance genes. METHODS: Virulence properties were analyzed phenotypically while antimicrobial susceptibility was tested by Kirby-Bauer agar disc diffusion method. In addition, 64 E. coli isolates were tested for 6 colicin genes, fimH, hlyA, traT, csgA, crl virulence genes and bla-CTX-M-15, bla-oxa-2 , and bla-oxa-10 resistance genes by polymerase chain reaction (PCR). RESULTS: Extra-intestinal pathogenic E. coli isolated from urine and blood samples represented a battery of virulence factors and resistance genes with a great ability to produce biofilm. Also, a significant association (P<0.05) among most of the tested colicin, virulence and resistance genes was observed. The observed associations indicate the importance and contribution of the tested factors in the establishment and the progress of infection especially with Extra-intestinal E. coli (ExPEC) which is considered a great challenging health problem. CONCLUSION: There is a need for studying how to control these factors to decrease the rate and the severity of infections. The relationship between virulence factors and resistance genes is complex and needs more studies that should be specific for each area.

Antimicrobial Activity of Silver-Treated Bacteria against other Multi-Drug Resistant Pathogens in Their Environment.

Silver is a potent antimicrobial agent against a variety of microorganisms and once the element has entered the bacterial cell, it accumulates as silver nanoparticles with large surface area causing cell death. At the same time, the bacterial cell becomes a reservoir for silver. This study aims to test the microcidal effect of silver-killed E. coli O104: H4 and its supernatant against fresh viable cells of the same bacterium and some other species, including E. coli O157: H7, Multidrug Resistant (MDR) Pseudomonas aeruginosa and Methicillin Resistant Staphylococcus aureus (MRSA). Silver-killed bacteria were examined by Transmission Electron Microscopy (TEM). Agar well diffusion assay was used to test the antimicrobial efficacy and durability of both pellet suspension and supernatant of silver-killed E. coli O104:H4 against other bacteria. Both silver-killed bacteria and supernatant showed prolonged antimicrobial activity against the tested strains that extended to 40 days. The presence of adsorbed silver nanoparticles on the bacterial cell and inside the cells was verified by TEM. Silver-killed bacteria serve as an efficient sustained release reservoir for exporting the lethal silver cations. This promotes its use as a powerful disinfectant for polluted water and as an effective antibacterial which can be included in wound and burn dressings to overcome the problem of wound contamination.