Search

Abstract Background Honey exhibits a broad spectrum of antibacterial activity against Gram‐positive and Gram‐negative bacteria, including methicillin‐resistant Staphylococcus aureus (MRSA) ones. Chitosan (Cs) is a mucoadhesive polymer that also has antibacterial properties. Special attention has been paid to the design of polymeric nanoparticles (NPs) as new nano drug delivery systems to overcome bacterial resistance and its problems. Objectives The aim of the present study is to synthesize Cs‐meropenem NPs with/without honey as an antibiofilm and antibacterial agent to inhibit Staphylococcus aureus. Methods This study synthesized meropenem and honey‐loaded Cs nanogels and subsequently characterized them by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and DLS‐zeta potential. Using the broth microdilution and crystal violet assays, the antibacterial and antibiofilm activity of meropenem and honey‐loaded Cs nanogel, free meropenem, free honey, and free Cs NPs were investigated in vitro against MRSA strains. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) was also used to test the cytotoxicity of several Cs‐NPs compound against the HEK‐293 regular cell line. Results The average size of meropenem and honey‐Cs‐NPs was reported to be 119.885 nm, and encapsulation efficiency was 88.33 ± 0.97 with stability up to 60 days at 4°C. The NPs showed enhanced antibiofilm efficacy against S. aureus at sub‐minimum inhibitory concentrations. Additionally, the cytotoxicity of meropenem and honey‐encapsulated Cs against the HEK‐293 normal cell line was insignificant. Conclusions Our findings suggested that meropenem and honey‐Cs‐NPs might be potential antibacterial and antibiofilm materials.

Abstract Background Bovine alphaherpesvirus 1 (BoHV‐1) is a serious disease with severe negative economic effects on the global cattle sector, especially in Iran. Objective This cross‐sectional study was carried out to examine the seroprevalence and associated risk factors of BoHV‐1 infection with progesterone levels and embryo death in 30‐day pregnant dairy cattle at Zagros Industrial Dairy Farm in Shahrekord, Iran. Methods Between December 2017 to February 2018, blood samples were obtained from 60 dairy cow herds. To determine whether BoHV‐1 was present, serum samples were examined using the ELISA for serum antibodies. To find progesterone (P4) in blood, the progesterone ELISA test was used. Results 96.7 % of sera tested positive for BoHV‐1 antibodies, according to the findings. Additionally, 60.34 % of blood samples that tested positive had an experience of abortion and significantly more inseminations that resulted in pregnancy, consistent with findings from other studies conducted in Iran and other nations. Conclusions Since this study is the first to document the risk factor for BoHV‐1 infection in Shahrekord, Iran, we could infer that the virus is extensively dispersed in this area.

Abstract Background Campylobacter jejuni and Campylobacter coli are the most significant Campylobacter species responsible for severe gastrointestinal disorders. Raw poultry meat is considered a source of Campylobacter transmission to the human population. Objectives The present study was aimed to assess the prevalence rate, antibiotic resistance properties, virulence characters and molecular typing of C. jejuni and C. coli strains isolated from raw poultry meat samples. Methods Three hundred and eighty raw poultry meat samples were collected and analysed for the presence of Campylobacter spp. using the microbial culture. Species identification was done using the Polymerase Chain Reaction. Disk diffusion was developed to assess the antimicrobial resistance pattern of isolates. The distribution of virulence and antimicrobial resistance genes was determined by PCR. Enterobacterial Repetitive Intergenic Consensus‐PCR was used for molecular typing. Results Campylobacter species were isolated from 6.25% of examined samples. C. jejuni and C. coli contamination rates were found to be 57.44% and 48.14%, respectively. C. jejuni strains harboured the highest resistance rate against serythromycin (42.59%), ampicillin (38.88%), ciprofloxacin (33.33%), chloramphenicol (31.48%) and tetracycline (31.48%). C. coli isolates harboured the highest resistance rate against ampicillin (73.07%), ciprofloxacin (73.07%), erythromycin (65.38%) and chloramphenicol (50%). AadE1 (44.44%), blaOXA‐61 (42.59%) and tet(O) (35.18%) were the most commonly detected resistance genes in C. jejuni and cmeB (34.61%) and blaOXA‐61 (34.61%) were the most commonly detected among C. coli strains. The most frequent virulence factors among the C. jejuni isolates were flaA (100%), ciaB (100%), racR (83.33%), dnaJ (81.48%), cdtB (81.48%), cdtC (79.62%) and cadF (74.07%). The most frequent virulence factors among the C. coli isolates were flaA (100%), ciaB (100%), pldA (65.38%) and cadF (61.53%). Conclusions The majority of C. jejuni and C. coli strains had more than 80% similarities in their ERIC‐PCR pattern, which may show their common source of transmission. The role of goose and quebec meat samples as reservoirs of virulent and antimicrobial resistant Campylobacter spp. was determined.

Abstract Background Arcobacter spp. has been considered an emerging foodborne pathogen and a hazard to human health. The dairy chain has been isolated from different sources; nevertheless, data on Arcobacter occurrence in raw milk and dairy products in Iran are still scant. Objective The present study investigates the prevalence, antimicrobial susceptibility and the presence of virulence genes of Arcobacters species isolated from milk and dairy products. Methods Then, a total of 350 raw milk samples and 400 dairy product samples were collected from dairy supply centers in Isfahan, Iran. Presumptive Arcobacter strains were obtained by enriching samples in Oxoid Arcobacter enrichment broth (AEB) followed by the filtration of enrichment product through 0.45‐μm pore size membrane filters laid onto non‐selective blood at 30°C under microaerophilic conditions. Molecular identification of Arcobacter cryaerophilus and A. butzleri was performed by Polymerase chain reaction (PCR) amplification of the 16S rRNA gene, followed by sequencing. The disc diffusion method was used to determine the antimicrobial susceptibility of isolates. Targeted resistance and virulence genes were detected using multiplex PCR. Results The results show a low recovery rate of Arcobacter spp. in milk. Arcobacters were found in all types of milk, except raw camel milk, but were absent from all dairy products. Arcobacter butzleri was the predominant species in raw milk. Detection of virulence genes shows that all virulence genes targeted were found among A. butzleri, and six (cadF, cj1349, irgA, mviN, pldA, tlyA) were found among A. cryaerophilus. All A. butzleri strains and some A. cryaerophilus strains isolated from milk were resistant to amoxicillin‐clavulanic acid and tetracycline. All A. cryaerophilus isolates from milk were susceptible to gentamycin, streptomycin, erythromycin and ciprofloxacin. The distribution of resistance genes in Arcobacter strains in milk shows that all isolates carried tet(O) and blaOXA‐61 genes. Conclusions In conclusion, the results indicate a low recovery rate of Arcobacter spp. in milk and milk products. However, a significant number of Arcobacter strains with putative virulence genes may be potential pathogens for humans and an overall increase in Arcobacter resistance to first‐line antibiotics. These results highlight the need for regular surveillance of Arcobacter strains in milk and milk products in Iran.

Abstract Background Infectious coryza (IC) is an invasive upper respiratory disease caused by Avibacterium paragallinarum that affects birds, particularly chickens. The objective of this study is to isolate, characterize and molecularly identify the bacterium A. paragallinarum in poultry birds, as well as to determine its antibiotic sensitivity and resistance. Methods A total of 10 chickens from four different Iranian farms with typical IC symptoms were used in this study. The nasal swabs were streaked onto chocolate agar plates and blood agar plates and incubated at 37°C in 5% CO2 for 24 to 48 h. As part of the identification of bacteria, bacteriological observations and polymerase chain reaction (PCR) testing are conducted. The antibiotic sensitivity tests were also performed using the disk diffusion method against A. paragallinarum and the prevalence in different farms was determined. Results By using biochemical assays and PCR analyses, seven strains of A. paragallinarum were isolated from samples of four chicken farms with typical IC clinical signs. Most isolates (4/7) showed the typical requirement for nicotinamide adenine dinucleotide (NAD) and an enriched CO2 atmosphere for growth. Three of the seven strains of A. paragallinarum were found to be novel NAD‐independent under anaerobic conditions. There was one biochemical biovar identified in terms of carbohydrate fermentation patterns, although changes in maltose carbohydrate fermentation patterns were detected in the No. 5 strain. All isolates were sensitive to gentamicin and spectinomycin. Three novel NAD‐independent strains (Nos.1, 5 and 7) were found to be multidrug‐resistant (MDR) and resistant to at least three classes of antibiotics. There was greater antibiotic resistance in the three NAD‐independent isolates than in normal NAD‐dependent bacteria. Conclusion By discovering NAD‐independent forms of A. paragallinarum, these species have a greater range than previously believed. A clear, cautious approach should be taken in diagnosing and possibly controlling IC.

Abstract Background Enterococcus faecalis is considered an opportunistic foodborne pathogen. The present study aimed to assess the prevalence, antimicrobial resistance, virulence characters, and molecular typing of E. faecalis strains isolated from seafood samples. Methods Two hundred and seventy‐six seafood samples were collected. E. faecalis was isolated from samples using bacterial culture. Furthermore, the disk diffusion assessed their antimicrobial resistance. Also, the distribution of virulence factors was determined using polymerase chain reaction (PCR) assay. Random amplified polymorphic DNA (RAPD) method was used for their molecular typing. Results Fifty‐six of 276 (20.2%) seafood samples were contaminated with E. faecalis. Fish harboured the highest contamination rate (30.0%). Isolates harboured the highest resistance rate towards oxacillin (100%), tetracycline (100%), erythromycin (100%), cefoxitin (89.2%), cefazolin (87.5%), trimethoprim‐sulfamethoxazole (85.7%), rifampin (69.6%), clindamycin (69.6%), and gentamicin (64.2%) antimicrobials. Efa (100%), ebpA (89.2%), ebpB (58.9%), ebpC (53.5%), and esp (51.7%) were the most commonly detected virulence factors among E. faecalis isolates. RAPD–PCR analysis showed 11 different molecular clusters considering the closeness of more than 80%. Conclusion Seafood samples were considered reservoirs of virulence and resistant E. faecalis strains. Different molecular clusters of isolates may reflect their diverse sources of contamination.

Abstract 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.