Antimicrobial resistance and genotyping ofvacA,cagA, andiceAalleles of theHelicobacter pyloristrains isolated from traditional dairy products

Assessment of virulence factors and antimicrobial resistance among the Pseudomonas aeruginosa strains isolated from animal meat and carcass samples

BACKGROUND

Pseudomonas aeruginosa bacteria are emerging causes of food spoilage and foodborne diseases. Raw meat of animal species may consider a reservoir of P. aeruginosa strains.

OBJECTIVES

The present survey was done to assess the prevalence, antibiotic resistance properties and distribution of virulence factors among the P. aeruginosa strains isolated from raw meat and carcass surface swab samples of animal species.

METHODS

Five hundred and fifty raw meat and carcass surface swab samples were collected from cattle and sheep species referred to as slaughterhouses. P. aeruginosa bacteria were identified using culture and biochemical tests. The pattern of antibiotic resistance was determined by disk diffusion. The distribution of virulence and antibiotic resistance genes was determined using polymerase chain reaction.

RESULTS

Forty-seven of 550 (8.54%) examined samples were contaminated with P. aeruginosa. The prevalence of P. aeruginosa in raw meat and carcass surface swab samples were 6.57 and 12%, respectively. P. aeruginosa isolates showed the maximum resistance rate toward penicillin (87.23%), ampicillin (85.10%), tetracycline (85.10%), gentamicin (65.95%) and trimethoprim (57.44%). The most commonly detected antibiotic resistance genes were BlaCTX-M (53.19%), blaDHA (42.55%) and blaTEM (27.65%). The most commonly detected virulence factors was ExoS (42.55%), algD (31.91%), lasA (31.91%), plcH (31.91%) and exoU (25.53%).

CONCLUSIONS

Meat and carcass surface swab samples may be sources of resistant and virulent P. aeruginosa, which pose a hygienic threat in their consumption. However, further investigations are required to identify additional epidemiological features of P. aeruginosa in meat and carcass surface samples.

Antimicrobial resistance of bacterial pathogens isolated from the infections of post maxillofacial surgery

Inappropriate antibiotic prescriptions contributed to a global issue of antimicrobial resistance. This study aimed to assess the prevalence of bacterial pathogens and antimicrobial resistance isolated from maxillofacial infections (MIs). Two hundred and twenty-two patients with different MIs were included in this study. Swab samples were taken from the site of infections. Samples were cultured, and isolated bacteria were identified using various biochemical tests. Antimicrobial resistance patterns of isolates were assessed by the disk diffusion method. The mean age of the patients was 50.8 years. The male-to-female ratio was 127/95 (P<0.05). Smoking and alcohol consumption were found in 60.36% and 37.38% of patients, respectively. Most patients had a ≤1-week infection duration (P<0.05). Abscess lesion was the most predominant infection type (P<0.05). The prevalence of aerobic bacteria among abscess, pus localization, and deep facial infections was 59.33%, 64.28%, and 46.66%, respectively. The prevalence of anaerobic bacteria among abscess, pus localization, and deep facial infections was 40.66%, 23.80%, and 53.33%, respectively. Staphylococcus aureus (10.36%) and Prevotella buccalis (8.55%) had the uppermost distribution amongst all examined samples. Isolated bacteria exhibited the uppermost resistance rate toward penicillin (65.76%), tetracycline (61.26%), gentamicin (58.10%), and ampicillin (57.65%) antimicrobials. The lowest resistance rate was obtained for linezolid (25.67%), ceftriaxone (31.08%), and azithromycin (31.08%) antimicrobials. Linezolid, ceftriaxone, and azithromycin had effective antimicrobial activities toward bacteria isolated from MIs. Therefore, cautious antibiotic prescription might decrease the prevalence of antimicrobial resistance in dental and maxillofacial infections.

Prevalence, Virulence Genes, Phylogenetic Analysis, and Antimicrobial Resistance Profile of Helicobacter Species in Chicken Meat and Their Associated Environment at Retail Shops in Egypt

Helicobacter pylori (H. pylori) and Helicobacter pullorum (H. pullorum) are frequently reported pathogens in humans and poultry, respectively. Nevertheless, the source of H. pylori is still unclear. This study aimed to detect Helicobacter spp. in chicken carcasses and to assess the antibiogram and the virulence genes of Helicobacter isolates. Three hundred chicken meat samples (100 each of chicken breast, liver, and gizzard), besides 60 swab samples from chicken processing surfaces, were collected from retail shops in Qalyubia Governorate, Egypt, and examined for the prevalence of H. pylori and H. pullorum. The 16S rRNA of three H. pylori and two H. pullorum isolates were sequenced to determine the genetic relationship between these two Helicobacter spp. Of the 300 chicken samples tested, 16 (5.33%) and 14 (4.67%) were positive for H. pylori and H. pullorum, respectively. Multiplex PCR revealed that the virulence genes vacuolating cytotoxin A (vacA)s1, cytotoxin-associated gene A (cagA), and restriction endonuclease-replacing gene A (hrgA) were detected in 66.7%, 77.8%, and 100% of H. pylori strains tested, respectively. H. pylori showed the highest resistance for clarithromycin, while H. pullorum exhibited the highest resistance towards erythromycin and ciprofloxacin. The study concluded that the chicken meat and giblets are potential sources of the virulent and antimicrobial-resistant strains of H. pylori of human origin.

Prevalence of Virulence Genes and Antigen Pattern in Helicobacter pylori-Infected Patients and the Level of Some Inflammatory Cytokines Compared with Non-infected Individuals

Background: The worldwide prevalence of Helicobacter pylori is about 50%. This bacterium needs a number of virulence factors for pathogenesis. Objectives: This study aimed to determine the prevalence of virulence genes (ureB, cytotoxin-associated gene A [cagA], and vacuolating cytotoxin [vacA]), as well as the antigenic profile in H. pylori strains. Methods: Eighty-five patients with abdominal pain, including 46 H. pylori-positive and 39 H. pylori-negative cases, were enrolled in this study. The serum levels of interleukin (IL)-17F, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ) cytokines were measured by multiplex kits and flow cytometry. After molecular identification by the ureC gene, vacA, cagA, and ureB genes were detected by polymerase chain reaction (PCR). Finally, after antigenic extraction, the whole-cell protein was exhibited by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE). Results: The prevalence of vacA, ureB, and cagA genes were 91.3%, 67.39%, and 50%, respectively. The frequency of genes and cell surface antigens were not significantly different based on the gastritis severity (P > 0.05). IL-17F significantly (P = 0.046) increased in the presence of 19.5 kDa (outer membrane protein [OMP]). Moreover, the OMP antigen significantly enhanced immunoglobulin A (IgA; P = 0.013). In the presence of the 66-kDa (ureB) antigen, the serum level of IFN-γ increased (p = 0.041). Finally, the CagA protein led to increased IgG antibody levels (p = 0.027). Conclusions: Early detection of H. pylori infection can play a crucial role in managing it. Our results suggest that IL-17F, TNF-α, and IFN-γ cytokines could be diagnostic markers. However, further studies are required to fully investigate this suggestion.

Study the relationship between Helicobacter pylori and bladder cancer

Given that bladder cancer is one of the most common cancers, and Helicobacter pylori infection also has 30-80% prevalence in different communities, this study investigates the role of H. pylori in developing bladder cancer; From December 2013 to February 2020, 200 patients with bladder tumors who underwent bladder tumor resection through the urethra in Kamkar-Arabnia Hospital were included in this study. H. pylori Ab, IgA, and IgG tests were first requested from all patients. If their antibodies were positive, other periodic tests including creatinine-sodium-potassium, Prothrombin Time (PT), Prothrombin Time Test (PTT), and International Normalized Ratio (INR), urinalysis, and culture were taken. The obtained results were analyzed using SPSS software version 25, and in the chi-square test, P <0.05 was considered a significant level; (3) Results: Based on laboratory findings, 66.5% of patients were H. pylori + (p <0.05). The result of the PCR test was positive in 4% of all patients. Besides, 6% of patients who tested positive for H. pylori Ab also showed positive PCR tests. Further studies are needed to investigate the association between H. pylori infection and bladder tumors to evaluate the proper role of H. pylori in tumors of the urinary system, especially the bladder and prostate, which have not been treated or reduced by treating H. pylori.

A survey of prevalence and phenotypic and genotypic assessment of antibiotic resistance in Staphylococcus aureus bacteria isolated from ready-to-eat food samples collected from Tehran Province, Iran

BACKGROUND

Resistant Staphylococcus aureus (S. aureus) bacteria are considered among the major causes of foodborne diseases. This survey aims to assess genotypic and phenotypic profiles of antibiotic resistance in S. aureus bacteria isolated from ready-to-eat food samples.

METHODS

According to the previously reported prevalence of S. aureus in ready-to-eat food samples, a total of 415 ready-to-eat food samples were collected from Tehran province, Iran. S. aureus bacteria were identified using culture and biochemical tests. Besides, the phenotypic antibiotic resistance profile was determined by disk diffusion. In addition, the genotypic pattern of antibiotic resistance was determined using the PCR.

RESULTS

A total of 64 out of 415 (15.42%) ready-to-eat food samples were contaminated with S. aureus. Grilled mushrooms and salad olivieh harbored the highest contamination rate of (30%), while salami samples harbored the lowest contamination rate of 3.33%. In addition, S. aureus bacteria harbored the highest prevalence of resistance to penicillin (85.93%), tetracycline (85.93%), gentamicin (73.43%), erythromycin (53.12%), trimethoprim-sulfamethoxazole (51.56%), and ciprofloxacin (50%). However, all isolates were resistant to at least four antibiotic agents. Accordingly, the prevalence of tetK (70.31%), blaZ (64.06%), aacA-D (57.81%), gyrA (50%), and ermA (39.06%) was higher than that of other detected antibiotic resistance genes. Besides, AacA-D + blaZ (48.43%), tetK + blaZ (46.87%), aacA-D + tetK (39.06%), aacA-D + gyrA (20.31%), and ermA + blaZ (20.31%) were the most frequently identified combined genotypic patterns of antibiotic resistance.

CONCLUSION

Ready-to-eat food samples may be sources of resistant S. aureus, which pose a hygienic threat in case of their consumption. However, further investigations are required to identify additional epidemiological features of S. aureus in ready-to-eat foods.

Milk and dairy products as a possible source of environmental transmission of Helicobacter pylori

Helicobacter pylori (H. pylori) is found worldwide, and it is estimated that more than 50% of the population is infected. The presence of H. pylori in the gastrointestinal tract is associated with the occurrence of serious human diseases such as chronic gastritis, duodenal ulcer or gastric cancer. Therefore, the International Agency for Research on Cancer classified H. pylori as a Group 1 carcinogen in 1994. The routes of H. pylori transmission are not yet precisely known. Many authors agree that humans may become infected by H. pylori through foodstuffs. Milk is one of the basic foods of people of all age categories. Helicobacter pylori has been isolated from milk derived from various livestock, such as cows, sheep, goat, camel or buffalo milk. This review research paper indicates that H. pylori may be present in different types of foods and suggests that consumption of milk and selected dairy products may be a source of H. pylori infection for humans.

Ligustrazine Attenuates Gastric Inflammation and Apoptosis in Helicobacter pylori-induced Gastric Epithelial Cells

Background: Stomach disorders, including gastric cancer and gastritis, are associated with the pathogenic bacterium Helicobacter pylori. Enhanced inflammation is the characteristic of H. pylori-induced gastritis. Ligustrazine exerts anti-inflammatory properties in mouse asthma models and acute kidney injury. Objectives: To determine the role of ligustrazine in H. pylori-induced gastritis. Methods: Normal gastric epithelial cell line (GES-1) was cultured with H. pylori at a multiplicity of infection (MOI) of 100: 1 for 24 hours. GES-1 cell line under H. pylori condition was incubated with 100 or 200 μM ligustrazine for 24 hours. Cell viability and apoptosis were investigated by MTT and flow cytometry assays, respectively. Inflammation was assessed by determining the levels and mRNA expression of interleukins (IL)-6/8, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein 1 (MCP-1) using ELISA and qRT-PCR analysis, respectively. Results: Helicobacter pylori infection reduced the viability and promoted the apoptosis of GES-1 cell line, accompanied by the enhanced activities of caspases 3 and 9. However, ligustrazine reversed the H. pylori-induced infection decreased viability, while increased apoptosis and caspases 3/9 activities in GES-1 cell line. Moreover, ligustrazine attenuated H. pylori-induced secretions of pro-inflammatory factors, IL-6/8, TNF-α, and MCP-1, in GES-1 cell line. The protein expression of inhibitor of NF-κB (IκBα) was downregulated in GES-1 cell line after H. pylori infection, while the protein expression levels of p65 and phosphorylation of IκBα were upregulated by H. pylori infection. On the contrary, ligustrazine decreased H. pylori-induced protein expression of IκBα, whereas increased protein expression of p65 and phosphorylation of IκBα. Conclusions: Ligustrazine exerted protective effects on H. pylori-induced gastric epithelial cells through inhibition of gastric inflammation and apoptosis and inactivation of NF-κB pathway.

Acinetobacter baumannii as a community foodborne pathogen: Peptide mass fingerprinting analysis, genotypic of biofilm formation and phenotypic pattern of antimicrobial resistance

Acinetobacter baumannii (A. baumannii) is one of the most common Gram-negative pathogens that represent a major threat to human life. Because the prevalence of Multidrug-resistant biofilm-forming A. baumannii is increasing all over the world, this may lead to outbreaks of hospital infections. Nonetheless, the role of raw meat as a reservoir for A. baumannii remains unclear. Here our research was aimed to exhibit the frequency, precise identification, and genotyping of biofilm-related genes as well as antimicrobial resistance of A. baumannii isolates of raw meat specimens. Fifty-five A. baumannii strains were recovered from 220 specimens of different animal meat and then identified by Peptide Mass Fingerprinting Technique (PMFT). All identified isolates were genotyped by the qPCR method for the existence of biofilm-related genes (ompA, bap, blaPER-1, csuE, csgA, and fimH). In addition, the antimicrobial resistance against A. baumannii was detected by the Kirby-Bauer method. Based on our findings, the frequency rate of 55 A. baumannii isolates was 46.55%, 32.50%, 15.00%, and 9.68% of sheep, chicken, cow, and camel raw meat samples, respectively. The PMFT was able to identify all strains by 100%. the percentages of csuE, ompA, bla_PER-1, bap, and csgA genes in biofilm and non-biofilm producer A. baumannii were 72.73%, 60%, 58.2%, 52.74%, and 25.45%, respectively. In contrast, the fimH was not detected in all non-biofilm and biofilm producer strains. The ompA, bap, blaPER-1, csgA were detected only in biofilm-producing A. baumannii isolates. The maximum degree of resistance was observed against amoxicillin/clavulanic acid (89.10%), gentamicin (74.55%), tetracycline (72.73%), ampicillin (65.45%), and tobramycin (52.73%). In conclusion, our investigation demonstrated the high incidence of multi-drug resistant A. baumannii in raw meat samples, with a high existence of biofilm-related virulence genes of ompA, bap, blaPER-1, csgA. Therefore, it has become necessary to take the control measures to limit the development of A. baumannii.

Prevalence and phenotypic pattern of antibiotic resistance of Acinetobacter baumannii isolated from different types of raw meat samples in Isfahan, Iran

Resistant Acinetobacter baumannii isolates are not only known as opportunistic nosocomial bacteria but may also be regarded as emerging bacterial contaminants in foods of animal origins. The present investigation was done to assess the prevalence and antibiotic resistance pattern of A. baumannii isolated from different types of raw meat samples. One hundred and ninety-four raw meat samples were collected and cultured for A. baumannii isolates. Culture-positive bacteria were also approved using the loop-mediated isothermal amplification (LAMP) technique. The disc diffusion method was used for antibiotic susceptibility testing. Out of 194 raw meat samples, 39 (20.10%) were positive for A. baumannii isolates. Ovine raw meat was the most commonly contaminated samples (32.14%). All of the culture-positive A. baumannii isolates were also approved using the LAMP assay. A. baumannii isolates harboured the highest prevalence of resistance against gentamicin (87.17%), tetracycline (79.48%), erythromycin (74.35%), azithromycin (66.66%), ciprofloxacin (58.97%), trimethoprim/sulphamethoxazole (56.41%) and rifampin (51.28%). The lowest prevalence of resistance was found against imipenem (17.94%) and chloramphenicol (28.20%). Raw bovine, ovine, caprine, camel and poultry meat samples were considered as the important sources of isolates resistant to some of the categories of antimicrobials used to treat infections caused by A. baumannii. Further studies are required to find the exact role of resistant A. baumannii isolates in the dissemination of antibiotic resistance to human population.