Future scope of plant-derived bioactive compounds in the management of methicillin-resistant Staphylococcus aureus: In vitro antimicrobial and antivirulence prospects to combat MRSA.

Methicillin-resistant Staphylococcus aureus (MRSA) is a foremost human and animal pathogen with public health and veterinary significance causing hospital and community infections and contagious bovine mastitis. Due to its ability to develop multidrug resistance (MDR) and its pathogenicity, MRSA infection control is becoming a global concern. Natural antibacterial options are needed to combat MDR development and infectious dissemination. This study investigated the antimicrobial resistance and virulence genes profiling of MRSA isolates and explored the antivirulence efficacy of trans-cinnamaldehyde, thymol, and carvacrol essential oils (EOs) against multivirulent and MDR-MRSA isolates. Thirty six S. aureus isolates (25%) were retrieved, of which 34 (94.4%) were MRSA. A high prevalence of MDR (66.7%) was monitored and all 53 molecularly verified isolates possessed icaA and cna virulence genes. Moreover, 94.1% of these isolates were multivirulent with 23.5% of them carrying icaA, cna, eta, tst, and sea virulence genes. Our data proved superior in vitro antimicrobial and antivirulence activities of trans-cinnamaldehyde, thymol, and carvacrol. They inhibited the growth of multi-virulent and MDR-MRSA isolates and downregulated the transcription of examined virulence genes. Our study suggests using EOs as prospective antimicrobials with excellent antivirulence activities against MRSA isolates. We provided data regarding the eventual role of phytogenics in prevention and control of MRSA infection.

New Insights into Listeria monocytogenes Antimicrobial Resistance, Virulence Attributes and Their Prospective Correlation.

Listeriosis is one of the most common foodborne diseases caused by Listeria monocytogenes (L. monocytogenes). A poor prognosis has been recorded for the invasive listeriosis, especially neurolisteriosis. In several countries throughout the world, foodborne infections with L. monocytogenes exceeded the legal safety limits in animal sourced foods. Therefore, we decided to investigate the variability, virulence and antimicrobial resistance profiles of this pathogen. Both phenotypic and genotypic methods were used for identifying L. monocytogenes isolates and confirming their virulence profiles. The antimicrobial resistances and their correlation analysis with the existence of virulence genes were detected. Additionally, sequencing and phylogenetic analysis based on L. monocytogenes inlA and inlB genes were undertaken. The prevalence rate (11.9%) and the resistance profiles of L. monocytogenes were shocking. The multi-drug resistance (MDR) phenotypes were common among our isolates (64.9%). Fortunately, the resistance phenotypes were always associated with low virulence arrays and the MDR strains possessed low virulence fitness. Herein, the high genotypic and phenotypic diversity of L. monocytogenes isolates and their weak clonality and adaptability highlighted the difficulty in controlling and managing this pathogen. Therefore, it is important to add more restriction guidelines from national authorities on the consumption of ready to eat foods.

Sequence Analysis, Antibiogram Profile, Virulence and Antibiotic Resistance Genes of XDR and MDR Gallibacterium anatis Isolated from Layer Chickens in Egypt.

Background: Gallibacterium anatis is incriminated frequently in severe economic losses and mortalities in the poultry industry. This study aimed to detect the prevalence of G. anatis in layer chickens, sequence analysis, the antibiogram profiles, and PCR screening of virulence determinants and antibiotic resistance genes. Methods: Accordingly, 300 samples (tracheal swabs, ovary and oviduct, and lung) were randomly collected from 100 diseased layer chickens from private commercial layer farms at Elsharkia Governorate, Egypt. The bacteriological examination was carried out. The retrieved isolates were tested for 16S rRNA-23S rRNA gene sequencing, antibiogram profiling, PCR screening of virulence (gtxA, fifA, and gyrB), and antibiotic resistance genes (bla ROB, aphA1, tetB, and tetH). Results: The prevalence of G. anatis was 25% in the examined diseased layer chickens. The sequence analyses emphasized that the tested strains derived from a common ancestor and exhibited a notable genetic similarity with other G. anatis strains from USA, China, and Denmark. The isolated G. anatis strains were highly resistant to sulfamethoxazole-trimethoprim, oxytetracycline, penicillin, ampicillin, kanamycin, neomycin, and erythromycin. The PCR revealed that the retrieved G. anatis strains carried gtxA, gyrB, and fifA virulence genes with a prevalence of 100%, 100%, and 38.3%, respectively. Approximately 30.1% of the retrieved G. anatis isolates were XDR to six antimicrobial classes and harbored bla ROB, aphA1, and tetB resistance genes. Moreover, 20.5% of the isolated G. anatis strains were MDR to three different classes and carried bla ROB and tetH resistance genes. Conclusion: Briefly, this study emphasized the existence of XDR and MDR G. anatis strains in poultry. Florfenicol and norfloxacin displayed a promising antimicrobial effect against the emerging XDR and MDR G. anatis in poultry. The emergence of XDR and MDR G. anatis is considered a public health alarm.

Epidemiological investigations on microbial infection and crystals causing feline lower urinary tract disease in tomcats in Ismailia, Egypt.

Background: Feline lower urinary tract disease (FLUTD) is a common disorder associated with the dysfunction of the urinary bladder or urethra in tomcats. Aim: A prospective study was carried out on the point prevalence and odds ratio (OR) of the FLUTD in Shirazi and Baladi tomcats at Ismailia Governorate, Egypt, recording the prominent clinical manifestation and identifying the antibiogram, virulence, and antimicrobial resistance genes of the causative microorganisms. Methods: A total number of 420 tomcats admitted to the veterinary clinics of Ismailia during the period June 2020 to May 2021 were examined for FLUTD. A total of 1,260 urine samples were collected and analyzed. Results: Hematuria, dysuria, and pollakiuria were the most evident signs recorded in a total of 120 tomcats diagnosed with FLUTD. The diagnosed cases of FLUTD were associated with causes like crystals (35.83%), pyogenic microorganisms (19.16%), and mixed cases (45.00%). The prevalence revealed highly significant (p < 0.01) increases in the cases caused by Escherichia coli, E. coli mixed cases, and calcium oxalate at >4 years; Staphylococcus aureus at ≤ 2 years; amorphous urate and phosphate at 2-4 and >4 years in Shirazi and ≤2 years in Baladi; triple phosphate at ≤2 years in Shirazi and >4 years in Baladi; and S. aureus mixed cases at ≤2 years. The OR of FLUTD revealed higher odds of associations with E. coli, E. coli mixed cases, S. aureus, amorphous urate, and triple phosphate, as well as lower odds with S. aureus, calcium oxalate, amorphous phosphate, and S. aureus mixed cases. Isolated E. coli revealed higher resistance to amoxicillin (AMX, 83.4%), ceftriaxone (83.4%), ceftazidime (CAZ, 75.0%), and cefoxitin (FOX, 50.0%), and S. aureus to oxacillin (100%), FOX (100%), AMX (85.8%), CAZ (76.2%), and FOX (50.0%). S. aureus-detected virulence genes were mecA, coa, spa, and tetK, and E. coli were fimH, iss, iutA, papC, blaTEM, blaCTX-M, and tetA. About 100% of E. coli and 76.1% of S. aureus isolates exhibited multidrug resistance. Conclusion: FLUTD in tomcats is associated with higher odds in E. coli, E. coli mixed cases, and triple phosphate at older ages (>4 years) with high antimicrobial resistance in the microbial isolates contributing to the disease.