Prevalence, genotyping and antibiotic resistance of Listeria monocytogenes and Escherichia coli in fresh beef and chicken meats marketed in Zanjan, Iran

Isolation and molecular characterization of multidrug‑resistant Escherichia coli from chicken meat

Antibiotics in animal farms play a significant role in the proliferation and spread of antibiotic-resistant genes (ARGs) and antibiotic-resistant bacteria (ARB). The dissemination of antibiotic resistance from animal facilities to the nearby environment has become an emerging concern. The present study was focused on the isolation and molecular identification of Escherichia coli (E. coli) isolates from broiler chicken meat and further access their antibiotic-resistant profile against different antibiotics. Broiler chicken meat samples were collected from 44 retail poultry slaughter shops in Prayagraj district, Uttar Pradesh, India. Standard bacteriological protocols were followed to first isolate the E. coli, and molecular characterization was performed with genus-specific PCR. Phenotypic and genotypic antibiotic-resistant profiles of all confirmed 154 E. coli isolates were screened against 09 antibiotics using the disc diffusion and PCR-based method for selected resistance genes. In antibiotic sensitivity testing, the isolates have shown maximum resistance potential against tetracycline (78%), ciprofloxacin (57.8%), trimethoprim (54.00%) and erythromycin (49.35%). E. coli bacterial isolates have shown relative resistant to amoxicillin-clavulanic acid (43.00%) and against ampicillin (44.15%). Notably, 64.28% E. coli bacteria were found to be multidrug resistant. The results of PCR assays exposed that tetA and blaTEM genes were the most abundant genes harboured by 83 (84.0%) and 82 (82.0%) out of all 99 targeted E. coli isolates, followed by 48.0% for AmpC (CITM) gene and cmlA (23.00%) for chloramphenicol resistance. It is notable that most of the isolates collected from chicken meat samples were multidrug resistant (> 3 antibiotics), with more than 80% of them carrying tetracycline (tetA) and beta-lactam gene (blaTEM). This study highlights the high risk associated with poultry products due to MDR-E. coli and promote the limited use of antibiotics in poultry farms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03950-7.

The Rapid Detection of Salmonella enterica, Listeria monocytogenes, and Staphylococcus aureus via Polymerase Chain Reaction Combined with Magnetic Beads and Capillary Electrophoresis

Food safety concerns regarding foodborne pathogen contamination have gained global attention due to its significant implications. In this study, we developed a detection system utilizing a PCR array combined with an automated magnetic bead-based system and CE technology to enable the detection of three foodborne pathogens, namely Salmonella enterica, Listeria monocytogenes, and Staphylococcus aureus. The results showed that our developed method could detect these pathogens at concentrations as low as 7.3 × 101, 6.7 × 102, and 6.9 × 102 cfu/mL, respectively, in the broth samples. In chicken samples, the limit of detection for these pathogens was 3.1 × 104, 3.5 × 103, and 3.9 × 102 cfu/g, respectively. The detection of these pathogens was accomplished without the necessity for sample enrichment, and the entire protocols, from sample preparation to amplicon analysis, were completed in approximately 3.5 h. Regarding the impact of the extraction method on detection capability, our study observed that an automated DNA extraction system based on the magnetic bead method demonstrated a 10-fold improvement or, at the very least, yielded similar results compared to the column-based method. These findings demonstrated that our developed model is effective in detecting low levels of these pathogens in the samples analyzed in this study. The PCR-CE method developed in this study may help monitor food safety in the future. It may also be extended to identify other foodborne pathogens across a wide range of food samples.

Biofilm formation, antibiotic resistance and genotyping of Shiga toxin-producing Escherichia coli isolated from retail chicken meats

1. The Shiga toxin-producing Escherichia coli (STEC) is a hazardous zoonotic agent for chicken meat consumers. This study determined the serogroups and evaluated the virulence genes, antibiotic resistance, biofilm-forming profiles and genetic relationships of STEC isolates in chicken meat.2. A total of 100 samples belonging to dressed-whole chicken and different parts of the chicken (wing, breast, thigh, drumstick) were collected between September and November 2019 from different retail markets in Kayseri, Türkiye.3. Phenotypic (identification, disc diffusion test, Congo red agar and microtitre plate tests) and molecular tests (identification, serogrouping, virulence factors, biofilm, antibiotic susceptibility, 16S rRNA sequencing and enterobacterial repetitive intergenic consensus-PCR for typing of the isolates) were carried out.4. E. coli was isolated from 35% of the samples and 35% of the samples harboured at least one STEC. Among 35 STEC isolates, 3 (8.5%), 6 (17.1%), 2 (5.7%) and 3 (8.5%) were found to be positive for fliCH2, fliCH8, fliCH11, fliCH19 genes, respectively. Out of 35 STEC positive isolates, 4 (11.4%) were identified as E. coli O157, from which 2 (5.7%) were E. coli O157:H7. E. coli O157 was detected in two (10%), one (5%), one (5%) of the thigh, drumstick and whole chicken samples, respectively.5. Biofilm-forming ability was reported in 33 (94.2%) of 35 E. coli isolates, whilst the biofilm-associated genes detected among 35 STEC isolates included csgA (88.5%), fimH (88.5%), bcsA (85.7%), agn43 (14.2%) and papC (8.5%). The STEC strains showed resistance against ampicillin (88.5%) and erythromycin (88.5%), followed by tetracycline (74.2%) and gentamicin (25.7%). However, the distribution of isolates harbouring bla_CMY, ere(A), tet(A) and aac(3)-IV antibiotic resistance genes was found to be 17.1%, 11.4%, 85.7% and 5.7%, respectively.6. ERIC-PCR showed that E. coli strains obtained from different parts and whole of chicken samples had genetic diversities. ERIC-PCR patterns grouped strains of 35 STEC into eight clusters designated A-H, with 73% similarity. Proper hygiene measures and staff training are essential for public health during poultry processing and in retail stores to control STEC.

In Vitro Assessment of Antimicrobial Activity of Phytobiotics Composition towards of Avian Pathogenic Escherichia coli (APEC) and Other E. coli Strains Isolated from Broiler Chickens

Escherichia coli infections (including APEC) in broiler chickens are not only a health and economic problem of the flock, but also a significant health threat to poultry meat consumers. The prophylactic and therapeutic effects of the phytobiotic composition on E. coli in broiler chickens were previously described. However, most of the data were related to the reference strains (for both in vitro and in vivo models). Based on the previous studies in human and animals, E. coli strains seem to be multidrug resistance. This, in turn, makes it necessary to develop effective alternative methods of treating this type of infection already at the stage of poultry production. In the present study, the antibacterial activity against various strains of E. coli (including APEC) was assessed for two innovative phytobiotics mixtures: H1, containing thymol, menthol, linalool, trans-anethole, methyl salicylate, 1,8-cineol, and p-cymene; H2, in addition to compounds from H1, containing terpinen-4-ol and γ-terpinene. The unique mixtures of phytobiotics used in the experiment were effective against various strains of E. coli, also against APEC, isolated from broiler chickens from traditional industrial breeding, as well as against those showing colistin resistance. The minimum inhibitory concentration (MIC) values for these unique mixtures were: For H1 1:512 for APEC and non-APEC E. coli strains isolated from day old chicks (DOCs), 1:512 for non-APEC, and 1:1024 for non-APEC isolated from broilers sample. For mixture H2, MIC for APEC from both type of samples (DOCs and broilers) was 1:1024 and for non-APEC (DOCs and broilers) was 1:512. The results suggest that phytobiotic compositions used in this study can be successfully used as a natural alternative to antibiotics in the treatment of E. coli infections in broiler chickens. The promising results may be a crucial point for further analyses in broiler flocks exposed to E. coli infections and where it is necessary to reduce the level of antibiotics or completely eliminate them, thus reducing the risk of foodborne infections.

Comparison of Nonthermal Decontamination Methods to Improve the Safety for Raw Beef Consumption

ABSTRACT

The object of this study was to examine nonthermal treatments to reduce foodborne pathogens in beef that is consumed raw. Foodborne illness pathogens (Escherichia coli, Salmonella, Staphylococcus aureus, and Listeria monocytogenes) were inoculated in the raw beef eye round. Death rates of foodborne illness pathogens were evaluated by nonthermal decontamination methods: high pressure processing (HPP) at 500 MPa for 2, 5, and 7 min; UV light-emitting diode (LED) radiation at 405 nm for 2, 6, and 24 h; hypochlorous acid water (HAW) at 100 ppm for 1, 3, and 5 min; 2.5% lactic acid (LA) for 1, 3, and 5 min; modified atmosphere packaging that replaced O2 to CO2 for 24 and 48 h with anaerogen (O2 levels were less than 1% and CO2 levels were 9 to 13%); and bio-gel application (BGA) for 24 and 48 h. For the bio-gel preparation, 5% sodium alginate was dissolved in 40 mL of glycerol and mixed with 0.2% CaCl2 dissolved in 60 mL of water, and this mixture was left at room temperature for solidification. Quality characteristics (color, pH, water activity, and texture) were measured after applying the practical nonthermal decontamination application. After HPP treatment for 7 min, inactivity rates were 4.4 to 6.7 Log CFU/g (100.0%) for E. coli, Salmonella, and L. monocytogenes and 1.7 Log CFU/g (98.0%) for S. aureus (P < 0.05). After treatment with UV LED for 24 h, reduced cell counts were 0.5 Log CFU/g (67.3%), 0.7 Log CFU/g (82.2%), and 0.3 Log CFU/g (47.1%) for E. coli, Salmonella, and S. aureus, respectively (P < 0.05), but no significant reduction of 0.0 Log CFU/g (4.3%) was observed for L. monocytogenes. When the beef was treated with HAW for 5 min, 0.6 Log CFU/g (73.3%) of E. coli, 0.5 Log CFU/g (66.2%) of Salmonella, 0.4 Log CFU/g (60.7%) of S. aureus, and 0.5 Log CFU/g (65.6%) of L. monocytogenes were inactivated. After the beef was treated with LA for 5 min, 1.8 Log CFU/g (98.5%) of E. coli, 3.0 Log CFU/g (99.9%) of Salmonella, 1.3 Log CFU/g (95.4%) of S. aureus, and 1.9 Log CFU/g (98.6%) of L. monocytogenes were inactivated. Modified atmosphere packaging for 48 h caused the inactivation of 0.3 Log CFU/g (51.8%) of E. coli and 0.1 Log CFU/g (19.2%) of Salmonella. After BGA treatment for 48 h, 0.3 Log CFU/g (55.2%) of E. coli and 0.4 Log CFU/g (58.7%) of Salmonella were significantly decreased (P < 0.05). HPP cooked the beef after 2 min of treatment. HAW and BGA changed the surface color of the beef, and LA reduced the pH of beef (P < 0.05). However, UV LED did not cause changes in the beef quality properties. These results indicates that UV LED can improve the food safety of raw beef without changes in beef quality.

HIGHLIGHTS