Occurrence and antimicrobial susceptibility of Listeria monocytogenes isolated from brined white cheese in Jordan.
Listeria monocytogenes is a serious foodborne pathogen that has been isolated from different dairy food products. Several foodborne outbreaks of listeriosis have been associated with consumption of cheese. The aims of this study were to determine the occurrence of L. monocytogenes and Listeria spp. in brined white cheese (BWC) sold in Jordan, and to determine the susceptibility of isolated L. monocytogenes to antimicrobials. Three hundred and fifty samples of 5 different types of BWC (akkawi, boiled, halloumi, pasteurized, and shellal) were collected from a local market in Jordan. The ISO (11290-1) procedure was followed for isolation and identification of Listeria spp. from cheese samples and a polymerase chain reaction (PCR) technique was used for confirmation of L. monocytogenes isolates. The VITEK2 automated system was used for testing antimicrobial susceptibility of L. monocytogenes isolates. The overall prevalence of Listeria spp. in cheese sample was 27.1%. L. monocytogenes was isolated from 39 (11.1%) samples. Other isolated species were L. grayi (6.9%), L. innocua (2%), L. ivanovii (4%), L. seeligeri (2%), and L. welshimeri (0.3%). The pH values and salt concentrations of L. monocytogenes positive cheese samples ranged from 5.10 to 6.32 and 5.64 to 13.16, respectively. L. monocytogenes isolates were sensitive or intermediate susceptible to imipenem, gentamicin, linezolid, teicoplanin, vancomycin, fusidic acid, trimethoprim/sulfamethoxazole, benzylpenicillin, ciprofloxacin, erythromycin, tetracycline, and rifampicin, but resistant to fosfomycin, oxacillin, and clindamycin.
Dept of Nutrition and Food Technology, Faculty of Agriculture, Jordan Univ of Science and Technology, Irbid 22110, Jordan. tosaili@just.edu.jo
Tareq M
TM
Osaili
Anas A
AA
Al-Nabulsi
Mohammad H
MH
Taha
Murad A
MA
Al-Holy
Akram R
AR
Alaboudi
Walid M
WM
Al-Rousan
Reyad R
RR
Shaker
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007597:Jordan; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D012492:Salts
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D012492:Salts