Detection of virulence genes of Staphylococcus aureus isolated from raw beef for retail sale in the markets of Ulaanbaatar city, Mongolia.

BACKGROUND: Staphylococcus aureus (S. aureus) is a highly virulent pathogen that causes food-borne illness, food poisoning, skin and soft tissue infections, abscesses, mastitis, and bacteremia. It is common for meat and meat products to become contaminated with S. aureus due to dirty hands, food storage conditions, food production processes, and unhygienic conditions, causing food poisoning. Therefore, we aimed to isolate S. aureus strain from the raw beef and reveal virulence genes and antibiotic resistance profile from isolated S. aureus strains. METHODS: In this study, 100 samples of raw beef were collected from 4 major market stalls in Ulaanbaatar city, Mongolia. S. aureus was detected according to the ISO 6888-1:2021 standard, and the nucA gene encoding the species-specific thermonuclease was amplified and confirmed by polymerase chain reaction (PCR). In the strains of S. aureus isolated from the samples, the genes encoding the virulence factors including sea, sed, tsst, eta, etb, and mecA were amplified by multiplex PCR. These genes are encoded staphylococcal enterotoxin A, enterotoxin D, toxic shock syndrome toxin, exotoxin A, exotoxin B and penicillin-binding protein PBP 2A, respectively. Antibiotic sensitivity test was performed by the Kirby-Bauer disc diffusion method. The Clinical and Laboratory Standard Institute guidelines as CLSI M100-S27 was used for analysis of the data. RESULTS: Thirty-five percent of our samples were detected contaminated with of the S. aureus strains. Subsequently, antibiotic resistance was observed in the S. aureus contaminated samples. Among our samples, the highest rates of resistance were determined against ampicillin (97.1%), oxacillin (88.6%), and penicillin (88.6%), respectively. Three genes including mecA, sea, and tsst from six virulence genes were detected in 17% of S. aureus strain-contaminated samples by multiplex PCR. The sed, etb and eta genes were detected in the 2.9%, 11.4% and 5.7% of our samples, respectively. CONCLUSION: The results show that S. aureus related contamination is high in the raw beef for retail sale and prevalent S. aureus strains are resistant to all antibiotics used. Also, our results have demonstrated that there is a high risk for food poisoning caused by antibiotic resistant S. aureus in the raw beef and it may establish public health issues. Genes encoding for both heat-resistant and nonresistant toxicity factors were detected in the antibiotic resistant S. aureus strains and shown the highly pathogenic. Finally, our study is ensuring to need proper hygienic conditions during beef's preparation and sale.

Detection and antibiotic resistance of diarrheagenic Escherichia coli from patients with diarrhea in Ulaanbaatar, Mongolia.

INTRODUCTION: Diarrheal diseases are common with worldwide distribution, and diarrheagenic Escherichia coli (DEC) strains are the main causative agents. The present study aimed to define the association of various pathotypes of E. coli from diarrheal patients in Mongolia. METHODOLOGY: A total of 341 E. coli strains were isolated from the stool of diarrheal patients. Bacterial susceptibility to antimicrobial agents was determined by the Kirby Bauer disk diffusion method. DEC isolates were identified by HEp-2 cell adherence assay and multiplex polymerase chain reaction (PCR). RESULTS: DEC pathogens were detected in 53.7% of 341 E. coli isolates. Enteroaggregative E. coli (EAEC) was the most common DEC pathotype identified by HEp-2 adherence assay and multiplex PCR methods in 97 samples (28.4%), followed by atypical enteropathogenic E. coli (EPEC) in 50 samples (14.7%), diffusely adherent E. coli (DAEC) in 25 samples (7.3%), enterohaemorrhagic E. coli (EHEC) in 6 samples (1.8%), enterotoxigenic E. coli (ETEC) in 4 samples (1.2%), and enteroinvasive E. coli (EIEC) in 1 sample (0.3%). DEC strains had > 50% antibiotic resistance against cephalothin, ampicillin, and trimethoprim/sulfamethoxazole. All tested DEC strains were susceptible to imipenem. Among the 183 DEC strains, 27 (14.8%) were extended spectrum beta-lactamase producing isolates, and 125 (68.3%) isolates were multiple drug resistant. CONCLUSIONS: We have identified six pathotypes of DEC from the clinical isolates tested and concluded that a high prevalence of antimicrobial resistance was observed in these pathotypes. EAEC was the most common pathotype identified and this is the first report of EHEC identification in Mongolia.

Effect of intraperitoneal docetaxel on ovarian function in mice.

Taxanes are important chemotherapeutic agents used to manage breast cancer and gynaecological malignancies. However, ovarian toxicity induced by the taxane docetaxel (DOC) is of great concern. We investigated DOC-induced toxicity in the ovaries of female CD1 strain mice. The mice were divided into control (saline), DOC-5 (5 mg/kg DOC), and DOC-10 (10 mg/kg DOC) groups and administered saline or DOC on the first day of the study and two weeks later. Two weeks after the second dose, the ovaries were removed for analysis after inducing superovulation. Ovary weight, the number of secondary follicles, and the total number of follicles were reduced after DOC administration. Additionally, the expression levels of caspase-3 and the pro-apoptotic protein Bcl-2 interacting mediator of cell death (BIM) increased. Our findings suggest that high-dose DOC induces damage to growing follicles; however, it may not affect primordial follicles.Impact statementWhat is already known on this subject? Docetaxel (DOC) is one of the most effective chemotherapeutic agents used to manage various cancers. Some in-vitro studies have examined paclitaxel-induced ovarian toxicity; however, limited research on DOC is available.What do the results of this study add? We investigated DOC-induced ovarian toxicity in female CD1 strain mice at 5 mg/kg and 10 mg/kg. We found that DOC reduced ovary weight, the number of secondary follicles, and the total number of follicles, with the higher dose having a higher effect.What are the implications of these findings for clinical practice and/or further research? We believe that our study makes a significant contribution to the knowledge about the effect of DOC on ovarian function.

Effects of peripheral oxytocin administration on body weight, food intake, adipocytes, and biochemical parameters in peri- and postmenopausal female rats.

Recent studies have revealed that the administration of oxytocin has beneficial effects on the regulation of body weight, food intake, and metabolic functions, especially in obese individuals. Obesity is common in women after the menopause and drives many components of metabolic syndrome. Weight gain in menopausal women has been frequently reported. Although obesity and associated metabolic disorders are frequently observed in peri- and postmenopausal women, there are few medical interventions for these conditions. In this study, we evaluated the effects of chronic oxytocin administration on appetite, body weight, and fat mass in peri- and postmenopausal female rats. Sixteen naturally premenopausal or menopausal rats were intraperitoneally injected with oxytocin (1,000 µg/day) for 12 days. The daily changes in their body weight and food intake were measured at the same time as the oxytocin and vehicle injections. Intraperitoneally administering oxytocin for 12 days significantly reduced food intake, body weight, and visceral adipocyte size. In addition, oxytocin administration caused reductions in serum triglyceride and low-density lipoprotein-cholesterol levels, while it did not disturb hepatic or renal functions or locomotor activity. This is the first study to show the effects of oxytocin on the metabolic and feeding functions of peri- and postmenopausal female rats. Oxytocin might be a useful treatment for metabolic disorders caused by the menopause or aging.

Mental stress promotes the proliferation of endometriotic lesions in mice.

Endometriosis is a condition in which tissue similar to the womb lining begins to grow in other sites, such as the ovaries or fallopian tubes. Endometriosis can cause pelvic pain, adhesion formation, and infertility. Here, we investigated the relationship between deterioration of endometriosis and inflammation of intraperitoneal adipose tissue in mice. We created a mouse model of endometriosis, then subjected these mice to stress loading. In the experimental mice, we measured protein expression levels of prostaglandin-E2, monocyte chemoattractant protein-1, and tumor necrosis factor-α using ELISA kits. We used quantitative real-time polymerase chain reaction to measure mRNA expression levels of inflammation-related enzymes and cytokines in lesions and adipose tissues. This study sugest that endometriotic lesions may progress in the presence of psychological stress in the presence of endometriosis. In addition, inflammation of the adipose tissue around the uterus may be involved in the development of endometriosis. However, this needs further consideration. Reducing or avoiding stress as much as possible may prevent the progression of endometriosis.

Intraperitoneal administration of activin A promotes development of endometriotic lesions in a mouse model of endometriosis.

PURPOSE: This study aimed to investigate the effect of intraperitoneal administration of activin on the occurrence of endometriosis using a mouse model of endometriosis. METHODS: A mouse model of endometriosis was prepared by intraperitoneally administering endometrial tissue and blood collected from donor mice to C57BL/6J 7-8- week-old recipient mice. A total of 400 µg of activin A was intraperitoneally administered to model mice in the activin group for 5 days. Intraperitoneal endometriotic lesions were confirmed macroscopically and IL-6 and TNF-α levels in washed ascites were measured by ELISA. RESULTS: Endometriotic lesions were observed in all mice. In the activin group, the maximum diameter of endometriotic lesions was significantly larger than that in control group (4.7?1.3 vs 2.9?0.9 mm, p?0.01). The total area of the lesion was also significantly higher in the activin group than in the control group (21.1?9.9 vs 8.8?5.4 mm2,p?0.01). Furthermore, IL-6 and TNF-α levels in ascites were significantly higher in the activin group than in the control group (IL-6 : 85.8?15.3 vs 75.1?19.3 pg/ml, p?0.05 ; TNF-α : 629.8?15.4 vs 605.9?11.4 pg/ml, p?0.05). CONCLUSION: Activin promotes occurrence of endometriosis. Inflammatory cytokines are also elevated by activin administration,suggesting that they may contribute to progression of endometriosis J. Med. Invest. 66 : 123-127, February, 2019.

Lipopolysaccharide promotes early endometrial-peritoneal interactions in a mouse model of endometriosis.

PURPOSE: The aims of this study were to clarify the effects of lipopolysaccharide (LPS) on the early development of endometriosis and on the production of cytokines and chemokines in the murine peritoneal cavity. METHODS: Endometriotic lesions were induced in C57BL/6J adult female mice by intraperitoneal injection of endometrial fragments plus blood or endometrial fragments plus blood with LPS. On day 7, endometriotic lesions were assessed by gross and microscopic evaluations. Time-dependent changes in the secretion of TNF-α,IL-6,and CXCL2/MIP-2 in peritoneal lavage fluid after the intraperitoneal injection of LPS (50 µg/body) were measured by their respective enzyme-linked immunosorbent assays. RESULTS: The areas of endometriotic lesions in the LPS group (10.8 8.6 mm2) were significantly larger than those in the control group (3.1 3.7 mm2).The levels of TNF-α and IL-6 peaked within 2 hours and the level of MIP-2 reached a maximum on day 1 after the injection of LPS. CONCLUSIONS: LPS promotes development of the early stages of murine endometriotic lesions. J. Med. Invest. 66 : 70-74, February, 2019.