Molecular Characterization ofCronobacter sakazakiiin Egypt, Survival and Thermoresistance at Different Temperatures: A Potential Public Health Risk

Cronobacter spp. in foods of plant origin: occurrence, contamination routes, and pathogenic potential

Cronobacter is an emerging bacterial pathogen associated with infections such as necrotizing enterocolitis, sepsis, and meningitis in neonates and infants, related to the consumption of powdered infant formula. In addition, this bacterium can also cause infections in adults by the ingestion of other foods. Thus, this review article aims to report the occurrence and prevalence of Cronobacter spp. in foods of plant origin, as well as the possible sources and routes of contamination in these products, and the presence of pathogenic strains in these foods. Cronobacter was present in a wide variety of cereal-based foods, vegetables, herbs, spices, ready-to-eat foods, and foods from other categories. This pathogen was also found in cultivation environments, such as soils, compost, animal feces, rice and vegetable crops, as well as food processing industries, and domestic environments, thus demonstrating possible contamination routes. Furthermore, sequence types (ST) involved in clinical cases and isolates resistant to antibiotics were found in Cronobacter strains isolated from food of plant origin. The identification of Cronobacter spp. in plant-based foods is of great importance to better elucidate the vehicles and routes of contamination in the primary production chain and processing facility, until the final consumption of the food, to prevent infections.

Draft genome sequence of Cronobacter sakazakii strain MEZCS99 sequence type 3 isolated from chicken in South Africa

OBJECTIVES

Cronobacter sakazakii is an emerging opportunistic foodborne pathogen that is frequently associated with life-threatening infections such as infantile septicemia, meningitis, and necrotizing enterocolitis. The emergence of antimicrobial-resistant, livestock-associated C. sakazakii is a great public health concern. Here, we report on the first draft genome sequence of C. sakazakii strain MEZCS99 sequence type 3 (ST3) isolated from feces from a healthy chicken in KwaZulu-Natal Province, South Africa.

METHODS

The genomic DNA of C. sakazakii was sequenced using an Illumina MiSeq platform (Illumina Inc., San Diego, CA). Generated reads were trimmed and de novo assembled. The assembled contigs were analyzed for virulence and antimicrobial resistance genes, extra-chromosomal plasmids, and multilocus sequence type (MLST). To compare the sequenced strains to other previously sequenced C. sakazakii strains, available raw read sequences of C. sakazakii were downloaded and all sequence files were treated identically to generate a core genome phylogenetic tree.

RESULTS

Intrinsic beta-lactam resistance gene blaCSA-1 was detected in MEZCS99. No colistin or other antibiotic resistance genes were detected. MEZCS99 belonged to ST3 and harbored an extra-chromosomal plasmid (IncFIB (pCTU3)). The genome of MEZCS99 strain showed two CRISPR/Cas cluster arrays of I-E (n = 1) and I-F (n = 1) type.

CONCLUSION

The genome sequence of strain MEZCS99 will serve as a reference point for molecular epidemiological studies of livestock-associated C. sakazakii in Africa. In addition, this study allows in-depth analysis of the genomic structure and will provide valuable information that helps understand the pathogenesis and antimicrobial resistance of livestock-associated C. sakazakii.

Prevalence and Antimicrobial Resistance of Virulent Listeria monocytogenes and Cronobacter sakazakii in Dairy Cattle, the Environment, and Dried Milk with the In Vitro Application of Natural Alternative Control

This study aims to detect the prevalence and antimicrobial resistance of Listeria monocytogenes and Cronobacter sakazakii in three dairy households and dried milk from different suppliers, and evaluate the antimicrobial effect of rose water, rose, and orange essential oils. In total, 360 samples were collected from cattle, the environment, and dried milk (n = 30). Antimicrobial activity was evaluated with twofold microtube dilution and the time-kill method. L. monocytogenes was identified in all households (13.3%) with a prevalence in the range of 5.8–17.5%, while C. sakazakii was identified in one household (5.3%). The former and latter pathogens were highly isolated from the feces at 20% and 2.5% and bedding at 12.5% and 1.6%, respectively. L. monocytogenes was isolated only from milk at 7.5%, but C. sakazakii was not detected in either milk or dried milk. L. monocytogenes strains were screened for virulence genes (iap, hylA, and actA). All strains were positive for the iap gene, while for hlyA and actA, the percentages were (35.4% 16.6%, respectively). L. monocytogenes strains showed high resistance against sulfamethoxazole–trimethoprim (100%), followed by gentamicin, penicillin, and imipenem (95.8%, 95.8%, and 91.6%, respectively). All C. sakazakii strains were susceptible to all tested antibiotics. The bactericidal activity of orange oil was the strongest, appeared after 1 h for both pathogens, followed by rose oil and then rose water.