Foodborne pathogens and disease最新文献

In recent years, Salmonella infection is a major global public health concern, particularly in food safety. This study analyzed the genomes of 102 Salmonella strains isolated between 2016 and 2023 from food, foodborne disease patients, and food poisoning incidents, focusing on their molecular characteristics, antibiotic resistance genes (ARGs), and virulence genes. S. enterica serovar Enteritidis (37.3%) and S. enterica serovar Typhimurium (21.6%, including its monophasic variant 1,4,[5],12:i:-) were the main strains among 22 serotypes. Multilocus sequence typing revealed 23 sequence types (STs), with ST11, ST19, and ST34 as the most prevalent. All strains carried at least 24 ARGs. Detection rates for aac(6')-Iy, bla_TEM-1, and sul2 ranged from 44.1% to 63.7%, mainly in S. Enteritidis and S. Typhimurium. Rates for qnrS1, sul1, and aadA were 12.8% to 16.7%, while mcr-1 appeared in one ST34 S. Typhimurium strain. All strains contained at least 98 virulence genes. The genes pefABCD, mig-5, and spvBCD were in 48.0% of strains, while rck was found in 36.3%, mainly linked to S. Enteritidis and S. Typhimurium. The tssM gene was found in 37.3% of the strains, exclusively in S. Enteritidis. Core genome single nucleotide polymorphisms (cgSNPs) analysis grouped the strains into nine clusters, with 75.5% belonging to three major groups. Food poisoning event 1 was correlated with cluster 3, while events 2 and 3 were linked to cluster 1. Across events, SNP differences among strains were ≤6. Strains with SNP differences ≤10 were also found in other clusters. This method is promising for tracking sporadic cases and identifying potential foodborne safety incidents. Salmonella strains in the region exhibit substantial genetic diversity, demonstrating the efficacy of cgSNPs analysis for source tracking. Ongoing surveillance is essential given the prevalence of ARGs and virulence genes. This study provides a data foundation for local Salmonella epidemiology.

Food safety is a critical issue in the 21st century due to antibiotic-resistant bacteria causing harmful foodborne diseases. This comprehensive study meticulously examined the presence of bacterial isolates, quinolone residue, and antimicrobial resistance genes in samples of broiler and fish meat. Forty samples were collected from various locations in the Faisalabad metropolis. The samples underwent culture on various types of agar, and the Vitek 2 compact system was used to confirm the isolates along with determining the minimum inhibitory concentration of antibiotics. Additionally, polymerase chain reaction was used to identify antimicrobial-resistant genes, and an enzyme-linked immunosorbent assay (ELISA) kit was employed to detect quinolone residue in each sample. Out of 40 fish samples, 66 polymicrobials were identified with Escherichia coli being the most prevalent (26.6%), followed by Klebsiella pneumoniae (16.6%) and Acinetobacter baumannii (15%). Furthermore, 70 polymicrobial were identified in the broiler samples, with 41.6% E. coli and 15% K. pneumoniae. In fish isolates, 14 (21%) qnr gene, 18 (27.2%) bla_CTX-M, and 11 (16.6%) bla_NDM-1, and in broiler samples, 19 (27.1%) qnr gene, 19 (27.1%) bla_TEM and 22 (31.4%) bla_CTX-M, and 5 (7.1%) bla_NDM-1 were found. Eighteen (45%) broiler and 7 (17.5%) fish samples with more than 100 µg per kg (ppb) for quinolone residues. The study concluded that the increased prevalence of multidrug-resistant bacteria and quinolone residue poses a significant threat to consumer health.

Listeriosis is a rare, life-threatening bacterial infection. Prompt, appropriate antibiotic treatment is essential to save lives. We aimed to investigate antibiotic selection and listeriosis knowledge among health care providers. We first performed a retrospective study on patients with listeriosis who were treated in a hospital in China from January 2013 to March 2023. Patient characteristics and antibiotic selections were recorded. Antibiotics were classified as effective or ineffective based on the efficacy classifications listed in The Sanford Guide to Antimicrobial Therapy (50^th edition). We then conducted a questionnaire survey of health care providers to investigate their listeriosis knowledge and practices between April 2023 to May 2023. Fifteen listeriosis patients were identified, with a case fatality rate of 26.7% (4/15). Empirical treatments assessed as effective antibiotics or ineffective antibiotics were given to 33.3% (5/15) and 66.7% (10/15) of the patients, respectively. After Listeria monocytogenes was identified, 40% (6/15) of the patients received an adjustment to their antibiotics, although 50% (3/6) patients still received ineffective antibiotics. The questionnaire survey of 77 participating health care providers showed that 32.9% (24/73) of the clinicians were unaware of the appropriate antibiotics for listeriosis. Most participants (83.1%, 64/77) would read the drug sensitivity report before selecting the antibiotics. The selection of effective antibiotics differed between the infectious diseases department and other departments (p < 0.001), but did not differ between junior title and other titles (p = 0.088). Most patients with listeriosis did not receive appropriate antibiotics, which might have accounted for the high fatality rate, and may have resulted from inadequate listeriosis knowledge. More education and correct reporting of drug sensitivity results are urgently needed.

During the 2019 Chinese National Microbiological Food Safety Surveillance program, Listeria monocytogenes was detected in ice cream samples produced by Manufacturer A. By comparing the sequences of isolates derived from the ice cream with those of isolates derived from humans, we identified one human-derived isolate that was genetically indistinguishable from one ice cream-derived isolates. The patient was hospitalized with listeriosis in Beijing, China in March 2019. Food history obtained from the patient indicated that he had consumed ice cream produced by Manufacturer A during the 30-day period before the onset of illness. No cases of listeriosis were detected after the ice cream produced by Manufacturer A was removed from the shelves. Overall, this report presents the first case of L. monocytogenes infection associated with ice cream in China.

Listeriosis is a relatively rare but severe foodborne disease, which has significant public health concern of persons with underlying conditions and pregnant women. This study aimed to estimate the morbidity, mortality, and fatality rates of listeriosis over a 10-year period and clarify the epidemiological features of the pathogen in Beijing, China, based on voluntary reporting of sentinel surveillance. A total of 228 listeriosis cases were reported with annual morbidity rate of 1.054 per million inhabitants, including 113 maternal-neonatal cases with mean annual morbidity rate of 63.401 per million live births in Beijing from 2013 to 2022.The morbidity rate increased from 0.094 to 0.868 per million inhabitants from 2013 to 2019 (p for trend = 0.003). The overall and maternal-neonatal fatality rate were 31.82% and 42.86%, respectively. Four serogroups were identified in this study, and 1/2b predominated (89 strains). We observed the morbidity rate of listeriosis increased in Beijing over the past 10 years. Maternal-neonatal cases accounted for a higher proportion than that described in other countries, considering population base and fertility policy in China, official recommendations targeting pregnant women should be actively promoted.

This investigation aimed to examine the virulence genes and antimicrobial resistance profiles of Shiga toxin-producing Escherichia coli (STEC) strains found in diarrheal calves in Xinjiang between 2016 and 2022. A total of 800 samples, including 232 fecal and 568 rectal swabs from calves under 2 months old with diarrhea, were analyzed for Shiga toxin (Stx)-encoding genes using polymerase chain reaction. The study characterized the isolates based on their stx subtypes, virulence genes, O serogroups, phylogenetic groups, hemolytic phenotypes, antibiotic resistance, and resistance genes. This investigation detected 32 STEC isolates, with stx1 and stx2 genes in 37.5% and 12.5% of the isolates, respectively. Additionally, half of the isolates contained both genes. The combination of stx subtypes was predominantly observed as follows: stx1a/stx2d (31.3%), stx1a only (31.3%), stx1a/stx2a/stx2d (12.5%), stx2d only (9.4%), stx1a/stx1d/stx2d (6.2%), stx1a/stx1d (6.2%), and stx2a/stx2d (3.1%). The eae gene was found in one isolate that carried stx1, stx2, and hlyA, defining it as enterohemorrhagic E. coli. Additionally, six STEC carrying the astA gene were identified as EAST1⁺ STEC. These isolates did not correspond to the serotypes in the "top seven" category. The phylogenetic analysis revealed that most strains belonged to groups B1 (43.8%) and A (40.6%), with 56.3% exhibiting hemolytic activity. Moreover, among the 34.4% resistant isolates (2021∼2022), the drug resistance rates of STEC isolates to tetracycline, florfenicol, ceftazidime, ampicillin, cefotaxime, gentamicin, and sulphamethoxazole ranged from 21.9% to 34.4%, to streptomycin, piperacillin, ceftazidime, aztreonam-polymyxin B, and cefepime ranged from 3.1% to 18.8%. All isolates exhibited multiple drug resistance. The most common resistance genes identified were floR (31.3%), tetA (25.0%), sulR (15.6%), strA and strB (12.5%), and bla_CTX-M-1, bla_TEM-1, and mph(A) (9.4%). These findings offer valuable information that might aid in developing preventative measures and enhance the comprehension of the epidemiological characteristics of STEC in calves.

Klebsiella quasipneumoniae is a recently described species that can be differentiated from Klebsiella pneumoniae. However, in clinical settings, they are frequently misidentified as K. pneumoniae. In this study, our objective was to conduct genomic characterization and bioinformatics analysis of K. quasipneumoniae subsp. quasipneumoniae (KpII-A) isolated from a sample obtained from a retail fish market in Assam, India. Notably, this particular isolate was identified as K. pneumoniae when identified using BD Pheonix™ M50 (BD Difco, USA). This represents a serious pitfall of conventional microbiological methods for distinguishing between K. pneumoniae and K. quasipneumoniae. In this connection, identifying differences in nuclear gene content is key to avoid misidentification. The isolate was confirmed to be KpII-A using species identification by Mash Screen and whole-genome sequencing by the Illumina platform. We report the draft genome sequence of this strain, comprising of 53 contigs with an average GC content of 58.11%. The annotation revealed 5,095 protein coding sequences, 69 tRNA genes, and 4 rRNA genes. The isolated strain acknowledges the presence of oqxA, oqxB, fosA, and bla_OKP-A-3 antimicrobial resistance genes (ARGs). Additionally two phage genomes were detected in contigs 3 and 19 of the bacterial genome. Based on the multilocus sequence typing and genome sequencing, the isolate was identified as a novel sequence type, ST5655, within the species K. quasipneumoniae under the phylogroup KpII-A. The presence of antimicrobial resistance genes in KpII-A, isolated from retail fish samples, raises concerns regarding transmission across barriers in ecological niches and possible transmission to consumers. Given that fish may serve as a potential vehicle for ARG transmission, our findings are highly relevant and paramount to human health. Moreover, our study supports the robustness of the sequence-based microbial identification.

Foodborne pathogens have always been of public health concern and represent safety issues for food processors. These pathogens develop new ways to overcome antibiotics, survive in different environmental conditions, and the ability to reproduce in many hostile environments configure them as serious health hazards. Considering the huge number of microorganisms, three bacterial representatives were selected to provide a better knowledge about the question of which one is the worst enemy for humans, from the food industry point of view, taking into consideration their multiplication specificity, virulence, and resistance. As we constantly are exposed to these pathogens in our nutritional habits, this overview aims to summarize the most relevant characteristics associated with the pathogenicity, clinical symptoms and most importantly, how deadly Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus can be in the hospital and the food industry, by comparing among them. Overall, the microbiological knowledge clearly suggests that while all three pathogens are dangerous, L. monocytogenes presents the highest risk of death due to their ability to cause severe complications in vulnerable populations as it presents a range of virulence factors that facilitate evasion of the immune system and cytological effects. Additionally, it shows great resistance to standard food processing and preservation techniques, making it one of the most difficult pathogens to control. Understanding the risks and characteristics of these foodborne pathogens is essential for implementing effective control measures to prevent their occurrence in food products and to promote public health.

Salmonella is a foodborne zoonotic pathogen that threatens food safety and public health. However, few people have conducted long-term and systematic studies on Salmonella contamination in food in Yantai City. In order to investigate the situation of Salmonella contamination in food and improve the ability of early warning and control of foodborne diseases, a total of 3420 samples from 20 categories were collected from 13 monitoring points in Yantai City, from 2010 to 2023. The difference in detection rate and bacterial strain of different monitoring points, different types, and different sources of samples was compared. Of the 3420 samples, 80 were positive with a detection rate of 2.34%. Salmonella detection rates were significantly different for samples collected at different monitoring sites. Salmonella was detected only in meat and meat products and catering food, and none of the other types were detected. The detection rate of Salmonella was higher in raw animal meat and raw poultry. Samples collected at the market stage had the highest detection rate (5.81%), and there was a significant difference in detection rate between samples from different sources (χ² = 36.93, p < 0.05). Eighty-one strains of Salmonella were detected out of 3420 samples (2 different strains were detected in 1 positive sample). The serological test identified 8 groups and 27 serotypes. The dominant serum groups were group B 30.86% (25/81), group E1 23.46% (19/81), and group D 16.05% (13/81). The main dominant serotypes were Salmonella give 17.28% (14/81), Salmonella enteritidis 16.05% (13/81), and Salmonella derby 13.58% (11/81). Meat and meat products and catering food were the main food products contaminated with Salmonella. The resulting secondary contamination is the hidden threat of foodborne diseases and should be given sufficient attention.