RESULTS: The genome size of LM115 and LM41 was 2,959,041 and 2,963,111 bp, respectively. These two strains shared approximately 90% homologous genes. Comparative genomics and phylogenomic analyses revealed that LM115 and LM41 were more closely related to the reference strains F2365 and EGD-e, respectively. Our virulence profiling indicated a total of 31 virulence genes shared by both analysed strains. These shared genes included those that encode for internalins and L. monocytogenes pathogenicity island 1 (LIPI-1). Both the Malaysian L. monocytogenes strains also harboured several genes associated with stress tolerance to counter the adverse conditions. Seven antibiotic and efflux pump related genes which may confer resistance against lincomycin, erythromycin, fosfomycin, quinolone, tetracycline, and penicillin, and macrolides were identified in the genomes of both strains.
CONCLUSIONS: Whole genome sequencing and comparative genomics analyses revealed two virulent L. monocytogenes strains isolated from ready-to-eat foods in Malaysia. The identification of strains with pathogenic, persistent, and antibiotic resistant potentials from minimally processed food warrant close attention from both healthcare and food industry.
Materials and Methods: A. hydrophila was biochemically identified and subjected to antibiotic susceptibility tests. The isolate was then intraperitoneally injected into red hybrid tilapia, and the mortality, clinicopathological changes, and LD50 were determined up to 240 h post-infection (hpi).
Results: The isolate demonstrated multiple antibiotic resistances (MAR) toward amikacin, ampicillin, cefotaxime, amoxicillin, trimethoprim-sulfamethoxazole, erythromycin, and streptomycin, with a MAR index of 0.5. The experimental infection of A. hydrophila at 105 CFU/mL in the red hybrid tilapia resulted in 100% mortality at 240 hpi. The LD50 was determined at 1.1×104 CFU/mL. Infected fish demonstrated occasional erratic swimming patterns, localized hemorrhages and depigmentation on the body and operculum areas, fin erosion, enlargement of the gall bladder, and hemorrhage in internal organs. Microscopic observation of infected fish revealed brain congestion, tubular necrosis, and glomerular shrinkage in the kidneys, necrosis of hepatocytes, and congestion of blood vessels in the liver.
Conclusion: The high virulence of A. hydrophila to the red hybrid tilapia emphasizes the importance of active, on-going monitoring of its prevalence in Malaysian tilapia farming.
Methods: S. aureus
strains were isolated from the nasal swabs of 200 health sciences students of a Malaysian university. Twelve classes of antibiotics were used to evaluate the antimicrobial susceptibility profiles with the macrolide-lincosamide-streptogramin B (MLSB) phenotype for inducible clindamycin resistance determined by the double-diffusion test (D-test). Carriage of resistance and virulence genes was performed by PCR onS. aureusisolates that were methicillin resistant, erythromycin resistant and/or positive for the leukocidin gene,pvl(n=15).
Results: Forty-nine isolates were viable and identified asS. aureuswith four of the isolates characterized as methicillin-resistantS. aureus(MRSA; 2.0%). All isolates were susceptible to the antibiotics tested except for penicillin (resistance rate of 49%), erythromycin (16%), oxacillin (8%), cefoxitin (8%) and clindamycin (4%). Of the eight erythromycin-resistant isolates, iMLSBwas identified in five isolates (three of which were also MRSA). The majority of the erythromycin-resistant isolates harbored themsrAgene (four iMLSB) with the remaining iMLSBisolate harboring theermCgene.
Conclusion: The presence of MRSA isolates which are also iMLSBin healthy individuals suggests that nasal carriage may play a role as a potential reservoir for the transmission of these pathogens.
DESIGN: General dental practitioners and specialists in the UAE were invited to participate in an online questionnaire survey which included questions on socio-demographics, practitioner's antibiotic prescribing preferences for various pulpal and periapical diseases, and their choice, in terms of the type, dose and duration of the antibiotic. The link to the survey questionnaire was sent to 250 invited dentists. Data were analyzed by descriptive statistics and chi-square tests for independence and level of significance was set at 0.05.
RESULTS: A total of 174 respondents participated in the survey (response rate = 70%). The respondents who prescribed antibiotics at least once a month were 38.5% while 17.2% did so, more than three times a week; amoxicillin 500 mg was the antibiotic of choice for patients not allergic to penicillin (43.7%), and in cases of penicillin allergies, erythromycin 500 mg (21.3%). There was a significant difference in the antibiotic prescribing practices of GDPs compared to endodontists and other specialties especially in clinical cases such as acute apical abscesses with swelling and moderate to severe pre-operative symptoms and retreatment of endodontic cases (p<0.05). Approximately, three quarters of the respondents (78.7%) did not prescribe a loading dose when prescribing antibiotics. About 15% respondents prescribed antibiotics to their patients if they were not accessible to patients due to a holiday/weekend.
CONCLUSIONS: In general, the antibiotic prescribing practices of UAE dentists are congruent with the international norms. However, there were occasions of inappropriate prescriptions such as in patients with irreversible pulpitis, necrotic pulps with no systemic involvement and/or with sinus tracts.