Isolation of Campylobacter spp. from a pig slaughterhouse and analysis of cross-contamination

Evaluation of vacuum packaging for extending the shelf life of Sardinian fermented sausage

Salsiccia sarda or Sardinian fermented sausage is a traditional dry-fermented sausage included in the list of traditional food products of Sardinia (Italy). At the request of some producing plants, the possibility of extending the shelf life of the vacuum-packed product up to 120 days was evaluated. Manufacturing of 90 samples, representing 3 different batches of Sardinian fermented sausage was carried out in two producing plants (A and B). In the packaged product and subsequently every 30 days for four months (T₀, T₃₀, T₆₀, T₁₂₀), the following analyses were conducted on all samples: physicochemical characteristics, total aerobic mesophilic count, Enterobacteriaceae count, detection of Listeria monocytogenes, Salmonella spp., mesophilic lactic acid bacteria, and coagulase-positive Staphylococci. Moreover, surfaces in contact and surfaces not in contact with food were sampled in both producing plants. Sensory profile analysis was also performed for every analysis time. At the end of the extended shelf life, pH values were equal to 5.90±0.11 (producing plant A) and 5.61±0.29 (producing plant B). Water activity mean values at T₁₂₀ were 0.894±0.02 (producing plant A) and 0.875±0.01 (producing plant B). L. monocytogenes was detected in 73.3% (33/45) of the samples from producing plant A, with mean levels of 1.12±0.76 log₁₀ CFU/g. In producing plant B, L. monocytogenes was never detected. Enterobacteriaceae were detected in 91.1% (41/45) of samples in producing plant A with mean values of 3.15±1.21 log₁₀ CFU/g, and in 35.5% (16/45) samples in producing plant B samples with mean values of 0.72±0.86 log₁₀ CFU/g. Salmonella and Staphylococcus aureus were never detected. Regarding environmental samples, the sites that were most contaminated by L. monocytogenes were the bagging table (contact surface) and processing room floor drains (non-contact surface) with a prevalence of 50% each (8/16 positive samples for both sampling sites). Sensory analysis results showed that at T₃₀ the overall sensory quality was at its highest;moreover, the visual-tactile aspect, the olfactory characteristics, the gustatory aspects, and the texture showed significant differences in samples throughout the shelf life, with a decreased intensity at 120 days of storage. Overall, the quality and sensory acceptance of the vacuumpacked Sardinian fermented sausage was not affected until 120 days of shelf-life. However, the possible contamination by L. monocytogenes calls attention to the hygienic management of the entire technological process. The environmental sampling was confirmed as a useful verification tool during control.

Isolation, identification and antibiotic resistance profile of thermophilic Campylobacter species from Bovine, Knives and personnel at Jimma Town Abattoir, Ethiopia

Thermophilic Campylobacter species are common cause of animal and human bacterial diseases with growing resistance to antimicrobials. The aim of this study was to determine the prevalence and antimicrobial susceptibility pattern of Campylobacter species from bovine, knives and personnel in Jimma Town, Ethiopia. Faecal samples and carcasses swabs were collected from cattle systematically selected from the annual plan of Jimma Municipal Abattoir. Personnel hand and knife swabs were collected after slaughtering each selected cattle. A cross-sectional study with systematic sampling method was conducted from October 2019 to September 2020 for the isolation, identification and antimicrobial susceptibility pattern of thermophilic Campylobacter species. Isolation and identification of Campylobacter species were performed according to the techniques recommended by the International Organization for Standardization, and in vitro antibiotic susceptibility testing was screened using the standard agar disc diffusion method as recommended by Clinical and Laboratory Standards Institutions. A total of 684 samples (171 samples from faeces, carcasses, knives and personnel hands, were collected independently). The overall prevalence of thermophilic Campylobacterspecies was 5.6% (38/684). Majority of the isolates were from faecal samples (12.9%, n = 22) followed by carcass swabs(4.1% n = 7), knife swabs(3.5% n = 6) and personnel hand swabs(1.8% n = 3). Isolated and identified species of C.jejuni, C. coli and C. lari accounted for 63.2%, 23.7% and 13.2%, respectively. The isolated Campylobacter species were found to be resistant to Cephalothin (100%), Ampicillin (60.5%), Cefotaxime (60.5%), Chloramphenicol (47.4%) and Tetracycline (42.1%). On the other hand, the isolates were susceptible to Nalidixic acid (86.8%), Ciprofloxacin (86.8%), Sulphamethazole (84.2%), Ceftriaxone (78.9%), Clindamycin (68.4%) and Cefixime (65.8%). 84.2% of the isolates showed multi-drug resistance for three-to-six drug classes. All the C. lari isolates were multidrug resistant. All the three isolated species of Campylobacter were resistant to Cephalothin, and most were multidrug resistant. Isolation of Campylobacter species from faecal, carcass, knife and hand swabs revealed possible risk of contamination and exposure to Campylobacter infection of those who consume raw meat. Therefore, enactment of hygienic practices during the slaughtering process, proper handling and cooking of meat and awareness creation on jurisdictional antibiotic usage are required to avoid Campylobacter infection.

Deciphering Resistome and Virulome Diversity in a Porcine Slaughterhouse and Pork Products Through Its Production Chain

We aimed to better understand resistome and virulome patterns on animal and process-area surfaces through a pig slaughterhouse to track possible contamination within the food production chain. Culture-dependent methods revealed high levels of microbial contamination, corresponding to mesophilic and pathogenic bacteria on both the animal and process-area surfaces mainly in the anesthesia (AA and AS) zone followed by “scorching and whip” (FA and FS) zone and also in the end products. To evaluate the potential risk of antibiotic resistance and virulence determinants, shotgun metagenomic DNA-sequencing of isolates from selected areas/products uncovered a high diversity and richness of antibiotic resistance genes (ARGs): 55–62 genes in the anesthesia area (AA and AS) and 35–40 in “animal-arrival zone” (MA and MS). The “scorching and whip” (FA and FS) area, however, exhibited lowered abundance of ARGs (1–6), indicating that the scalding and depilating process (an intermediate zone between “anesthesia” and “scorching and whip”) significantly decreased bacterial load by 1–3 log₁₀ but also diminished the resistome. The high prevalence of antibiotic-inactivating enzyme genes in the “animal-arrival zone” (60–65%) and “anesthesia” area (56%) were mainly represented by those for aminoglycoside (46–51%) and lincosamide (14–19%) resistance, which did not reflect selective pressures by antibiotics most commonly used in pig therapy—tetracyclines and beta-lactams. Contrary to ARGs, greater number of virulence resistance genes were detected after evisceration in some products such as kidney, which reflected the poor hygienic practices. More than 19 general virulence features—mainly adherence, secretion system, chemotaxis and motility, invasion and motility were detected in some products. However, immune evasion determinants were detected in almost all samples analyzed from the beginning of the process, with highest amounts found from the anesthesia area. We conclude that there are two main sources of contamination in a pig slaughterhouse: the microorganisms carried on the animals’ hide, and those from the evisceration step. As such, focussing control measures, e.g., enhanced disinfection procedures, on these contamination-source areas may reduce risks to food safety and consumer health, since the antibiotic and virulence determinants may spread to end products and the environment; further, ARG and virulence traits can exacerbate pathogen treatments.

Occurrences of thermophilic Campylobacter in pigs slaughtered at Morogoro slaughter slabs, Tanzania

Occurrences of thermophlic Campylobacter in pigs and pig carcasses was investigated in a cross-sectional study that was carried out in three selected slaughter slabs in Morogoro municipality, Tanzania. Before sampling, the slab hygiene, slaughter, carcass dressing, and meat handling was assessed. Fecal samples were collected from 66 slaughter pigs at the kill floor. After slaughter, a 100-cm(2) area on medial surface of the thigh muscles of dressed carcasses was sampled using sterile cotton swabs. Thereafter, the jejunal, cecal, and colon contents were also sampled. The samples were subjected to standard bacteriological examination using Skirrows protocol. In all slaughter slabs visited, it was found that pig slaughter, dressing, and meat handling was done on the ground under unhygienic condition. All the slaughter slab environment were dirty and had neither tap water or drainage systems. Thermophilic Campylobacter prevalence in slaughtered pig was 66.7% while contamination rate of dressed carcasses was 10.6%. Of the Campylobacter-positive carcasses, five (12.2%) were from the animals which were also positive to Campylobacter. The isolation rate of Campylobacter in the cecum was higher (34.8%) compared to the small intestines (28.8%) and colon (16.7%) although the difference was not statistically significant (P > 0.05). Campylobacter jejuni was the most prevalent species as it constituted 74% of all isolates, while Campylobacter coli was isolated at 26%. This suggests possible risks of infection to people through consumption of contaminated pork or through contact with infected pigs. Cecum was found to be the major part of intestine highly colonized by Campylobacter.

Clonal population structure and antimicrobial resistance of Campylobacter jejuni in chicken meat from Belgium

Campylobacter jejuni is one of the most important causes of human diarrhea worldwide. In the present work, multilocus sequence typing was used to study the genotypic diversity of 145 C. jejuni isolates from 135 chicken meat preparations sampled across Belgium. Isolates were further typed by pulsed-field gel electrophoresis, and their susceptibilities to six antimicrobials were determined. Fifty-seven sequence types (STs) were identified; 26.8% of the total typed isolates were ST-50, ST-45, or ST-257, belonging to clonal complex CC-21, CC-45, or CC-257, respectively. One clonal group comprised 22% (32/145) of all isolates, originating from five different companies and isolated over seven sampling months. Additionally, 53.1% of C. jejuni isolates were resistant to ciprofloxacin, and 48.2% were resistant to tetracycline; 28.9% (42/145) of all isolates were resistant to both ciprofloxacin and tetracycline. The correlation between certain C. jejuni clonal groups and resistance to ciprofloxacin and tetracycline was notable. C. jejuni isolates assigned to CC-21 (n = 35) were frequently resistant to ciprofloxacin (65.7%) and tetracycline (40%); however, 90% (18/20) of the isolates assigned to CC-45 were pansusceptible. The present study demonstrates that certain C. jejuni genotypes recur frequently in the chicken meat supply. The results of molecular typing, combined with data on sample sources, indicate a possible dissemination of C. jejuni clones with high resistance to ciprofloxacin and/or tetracycline. Whether certain clonal groups are common in the environment and repeatedly infect Belgian broiler flocks or whether they have the potential to persist on farms or in slaughterhouses needs further investigation.