Listeria monocytogenes are Gram-positive bacilli cause listeriosis, associated with high rates of hospitalization and mortality. A total of 1362 samples were investigated included 647 clinical samples and 715 from food. This study investigated the differences in the seasonal occurrence of L. monocytogenes in Kurdistan region-Iraq.   L. monocytogeneswas found in 48 samples (3.52%) out of 1362 samples. There were 7/642(1.09%) human clinical samples diagnosed with cold and moderate weather (November, December 2016, and January, February, April 2017). While 41/715(5.73%) of L. monocytogenesisolates were found among food samples, meat samples (n=37) and dairy samples (n=4). A total of 37/476 (7.77%) of the L. monocytogenes isolates in meat samplesweredetected during warm weather (from July through October 2016). In addition, L. monocytogenesin dairy products was found to be by 4/239 (1.68%), were isolated during the moderate season (October, November 2016, and April, May 2017). The study found that the incidence of meat contamination by L. monocytogenesincrease significantly during the warm season in comparison with other seasons. Furthermore, the cases of human Listeriosis caused correlated well with the seasonal levels of L. monocytogenesfound in dairy products. A statistically significant difference in the occurrence of L. monocytogenesisolates and seasons were identified in this study (P value= <0.05).

Listeria monocytogenes is one of the most important foodborne pathogens in human worldwide. In present study, this bacterium was isolated from different animal products and human clinical samples. The isolates were characterized by antibiotic susceptibility tests, serotyping, virulence genes and 16SrRNA sequencing. Out of 1362 investigated samples, Listeria monocytogenes were identified in 48(3.5%) of samples. Seven samples 1.1% were from human, while 41(5.7%) were from food samples. The majority of food isolates were resistant to penicillin, cephalexin, doxycycline, ampicillin and vancomycin; while variable resistance to the other antibiotics was observed. Serotyping of food and human isolates found that 7 of human isolates and 28 of food isolates belonged to serogroup 1/2a (3a). While, 8 isolates from food samples belonged to the serogroup 4b. Five fresh red meat isolates belonged to the serogroup 1/2b. All food and human isolates contained virulence genes actA, hlyA, plcA and iap genes. Phylogenetic analysis based on 16SrRNA sequencing showed that the L. monocytogenes isolated from milk were not closely related to the meat and human isolates. This data suggests that the antibacterial resistant Listeria monocytogenes are widely spread within the animal products rather than the clinical samples. The most common serogroup within the isolated strains was 1/2a (3a). Surprisingly, all isolates found to be virulent strains depending on the virulence genes detection. Therefore, it is highly recommended to apply strict biosecurity measurements on food and food processing environment to avoid or to maintain the spread of the bacterial infection within the area.

Multi-drug resistance in Listeria monocytogenes is considered a major public health problem associated with foodborne outbreaks and causes high hospitalization and mortality rates. This study aimed to investigate the antimicrobial resistant genes among Listeria monocytogenes isolated from meat and clinical samples. Phenotypically, the isolates were tested for their susceptibility against the 12 most commonly used antimicrobials in veterinary and human therapy via the disc diffusion method, while conventional PCR was performed to study the presence or absence of 14 resistance genes predicted in L. monocytogenes isolates. The study established that 30(66.66%) of L. monocytogenes isolates showed phenotypic multi-drug resistance against at least three antimicrobial classes. Furthermore, high resistance frequencies were reported among commonly used antibiotics for listeriosis therapy. The present study revealed that the investigated isolates show resistance against tetracycline 33(73.3%), ampicillin 29(64.4%), penicillin 28(62.2%), erythromycin 26(57.8%), and gentamycin, clindamycin and vancomycin 24(53.3% each). Of the 45 L. monocytogenes isolates studied, 37(82.2%) were phenotypically susceptible to meropenem, followed by ciprofloxacin 36(80.0%) and SXT 30(66.7%). PCR amplification of antimicrobial resistance genes established the occurrence of antibiotic resistance genes in all studied L. monocytogenes isolates. Notably, 41(91.11%) of these isolates exhibited more than five resistance genes. Surprisingly, penA and ampC were detected in all L. monocytogenes strains   45(100%), followed by ermB 44(97.8%), tetA 38(84.4%), tetG 32(71.1%), and vanB 30(66.7%). Moreover, vanA 22(48.9%) and tetB 18(40.0%) were detected less frequently. The lowest incidences of resistance genes were observed in L. monocytogenes carrying tetD 4(8.9%) and cmlA 6(13.3%). In conclusion, the study demonstrates that the majority of L. monocytogenes from human and meat samples displayed a high index of resistance to a variety of agents used for clinical listeriosis treatment adding further burden to the existing global antibiotic resistance problem.

Carbapenem-resistant Acinetobacter baumannii has been considered one of the major threats to patients worldwide. To evaluate carbapenemase in several clinical isolates using phenotypic and genotypic approaches. A total of 49 A. baumannii isolates were tested against imipenem and meropenem discs on Muller Hinton agar, then screened phenotypically through the modified Hodge test (MHT), combined disc test (CDT) and modified carbapenem inactivation method (mCIM). The tested isolates have been subjected to polymerase chain reaction (PCR) detection to identify some carbapenemase-encoding genes and one insertion sequence. The carbapenem resistance profile showed 96% and 94% resistance to imipenem and meropenem, respectively. MHT and mCIM were able to produce carbapenemase in 94% and 98% of isolates, respectively, while CDT was able to produce metallo-B-lactamase (MBL) only in 59.2% of isolates. The PCR amplification of blaOXA-51 has been observed in all isolates. We found blaOXA-23 in 98% of isolates. Insertion sequence ISAba1 was present in all positive blaOXA-23 strains (98%). A blaVIM gene encoding MBL was present in 71% of isolates, but none of the isolates has been positive for blaKPC and blaNDM. The high rate of carbapenem resistance in A. baumannii became a serious threat worldwide. Concerning phenotypic tests, mCIM was the most sensitive compared to MHT and CDT. This study established that blaOXA-23 and blaOXA-51 have been the most prevalent among class D carbapenemase, and blaVIM among class B carbapenemase. The present study suggests that there might be silent carbapenemase genes in carbapenem-sensitive strains.

Listeria monocytogenes is a facultative intracellular, food-borne zoonotic-bacterium causing life-threatening infections worldwide with a significant mortality rate in both humans and animals. The aim of the study was to examine the existence of five crucial virulence-associated genes (inIA, inIB, inIC, inIJ and prfA) in 48 L. monocytogenes isolates that were obtained from human and different food products using multiplex Polymerase Chain Reaction (PCR). The most frequent genes among isolates were inIC (93.8%), inIB (91.7%) and inIJ (83.3) followed by prfA (81.2%) and inIA (79.2%). Regardless of the source of bacteria, all tested isolates showed the prevalence of multiple virulence-associated genes. The presence of three virulence genes was detected in 20.8%, four of five virulence genes were found in 33.3% of isolates, and 45.8% of isolates carried all five virulence genes. In conclusion, the presence of potential virulence genes increases the pathogenicity of L. monocyogenes. Furthermore, the occurrence of multiple virulence related genes in a single isolate may imply the presence of highly virulent isolates. To investigate the connection between those genes and clinical outcomes, more research is needed.