The sensory evaluation and antimicrobial efficacy of Lactobacillus acidophilus supernatant on Salmonella enteritidis in milk.

Postbiotics are metabolites derived from living probiotic bacteria like Lactobacillus strains, during the fermentation process and/or produced in pure form on laboratory scales. These compounds, depending on the type of probiotic from which they are prepared, have specific antibacterial agents such as: organic acids, bacteriocins, short-chain fatty acids, and peptides. The objective of this study was to investigate the effect of Lactobacillus acidophilus supernatant (LAS) on the growth pattern of Salmonella enteritidis at fluctuating temperatures and the sensory evaluation of milk that contains this probiotic. Baranyi and Roberts's model determined the best-fit curve for the microbial growth. According to mathematical equations, the highest and lowest specific growth (µ max) rates of S. enteritidis were obtained at 0.055 h-1 and 0.0059 h-1 and also highest and lowest maximum generation time (MGT) values were obtained at 20.06 h and 8.85 h, respectively. Sensory evaluation by the Triangel test reveals that LAS could not establish a significant (p > .05) adverse effect on milk perceptible. Regarding the results obtained in the present study, LAS, without causing adverse sensory change, could act as a safe food additive for the control of bacterial pathogens and reducing food waste, particularly in milk and milk-containing food products.

Genotyping and antibiotic susceptibility of Campylobacter species isolated from raw milk samples in Qazvin, Iran.

OBJECTIVE: Campylobacter species are major causes of foodborne illnesses, with unpasteurized milk being a significant carrier of these bacteria, posing a public health risk. One of the challenges in managing Campylobacter infections is the emergence and spread of antibiotic resistance. We conducted a study in Qazvin, Iran, testing 84 raw cow's milk samples to determine the frequency of C. jejuni and C. coli using culture-based and multiplex PCR methods. Additionally, the disk diffusion and RAPD-PCR approaches were utilized to evaluate the phenotypic antibiotic resistance profile and genetic diversity of Campylobacter strains. RESULTS: The findings indicated that Campylobacter spp. was present in 19.05% of the samples, with C. coli being the predominant isolate. We tested eight antibiotic agents, and the resistance levels of the isolates were as follows: erythromycin 100%, tetracycline 75%, doxycycline 56.25%, ceftriaxone 43.75%, chloramphenicol 37.5%, amoxicillin-clavulanic acid 25%, nalidixic acid 12.5%, and azithromycin 6.25%. Genetic diversity analysis categorized Campylobacter isolates into 39 clusters, indicating a wide diversity among strains. However, no significant correlation was observed between antibiotic resistance and cluster patterns. These findings underscore the role of raw milk as a reservoir for Campylobacter spp. and highlight the substantial antibiotic resistance and genetic diversity within the species population.

Prevalence of Foodborne Bacterial Pathogens and Antibiotic Resistance Genes in Sweets from Local Markets in Iran.

BACKGROUND: This study aimed to investigate the prevalences of some important antibiotic-resistance genes (ARGs) and foodborne bacterial pathogens in sweet samples collected from local markets in Iran. METHODS: Forty sweet samples were collected. Foodborne pathogens and ARGs were detected in the sweet samples by conventional and multiplex PCR assays using species-specific primers. RESULTS: Staphylococcus aureus, Cronobacter sakazakii, Shigella spp., Campylobacter jejuni, and Campylobacter coli were detected and identified in 47.5%, 20%, 45%, 5%, and 30% of the sweet samples, respectively. We found S. aureus and Shigella spp. were the most prevalent bacterial pathogens. S. aureus was found to be the most frequent pathogenic bacteria profiled in these samples. We also found a significant correlation between the presence of C. coli and Cr. sakazakii. We detected the blaSHV resistance gene in 97.5% of the sweet samples; however, blaTEM was detected in only one sample (2.5%). CONCLUSIONS: Regarding these results, we suggest preventive strategies such as implementing automation of food processing; monitoring the personal hygiene and health of food handlers, and testing regularly for antibiotic resistance in raw materials and products.

Influence of menthol on biofilm formation, ergosterol content, and cell surface hydrophobicity of Candida glabrata.

Resistance to synthetic antifungals has become one of the leading public health challenges around the world. Accordingly, novel antifungal products like naturally occurring molecules can be one of the potential ways to reach efficient curative approaches to control candidiasis. This work evaluated the effect of menthol on cell surface hydrophobicity (CSH), biofilm formation, growth, and ergosterol content of Candida glabrata, a yeast with a high resistance against antifungal agents. Disc diffusion method (susceptibility to synthetic antifungals), broth micro-dilution method (Susceptibility to menthol), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction assay (biofilm formation), High-performance liquid chromatography (HPLC) technique (ergosterol content), and adherence to n-hexadecane (CSH) were employed to determine the influence of menthol against C. glabrata isolates. The minimum inhibitory concentration (MIC) range of menthol versus C. glabrata was 1250-5000 µg/mL (mean ± SD: 3375 ± 1375 µg/mL). The mean rate of C. glabrata biofilm formation was decreased up to 97.67%, 81.15%, 71.21%, 63.72%, 47.53%, 26.31%, and 0.051% at 625, 1250, 2500, 5000, 10 000, 20 000, and 40 000 µg/mL concentrations, respectively. The percentages of CSH were significant in groups treated with MIC/2 (17.51 ± 5.52%) and MIC/4 (26 ± 5.87%) concentrations of menthol. Also, the percentage changes in membrane ergosterol were 15.97%, 45.34%, and 73.40% at 0.125, 0.25, and 0.5 mg/mL concentrations of menthol, respectively, in comparison with untreated control. The results showed the menthol impact versus sessile and planktonic C. glabrata cells, and the interference with ergosterol content, CSH, and biofilm formation, which made it a potent natural antifungal.

Effects of Probiotic Saccharomyces boulardii Supernatant on Viability, Nano-Mechanical Properties of Cytoplasmic Membrane and Pro-Inflammatory Gene Expression in Human Gastric Cancer AGS Cells.

BACKGROUND: Gastric cancer has been recognized as the second most probable cause of death in humans from cancer diseases around the world. Postbiotics, supernatant, and metabolites from probiotic microorganisms have recently been used widely to prevent and treat cancer diseases in humans, without any undesirable side effects. This study explores the antiproliferative and antitumor activities of the probiotic Saccharomyces cerevisiae var. boulardii supernatant (SBS) against AGS cancer cells, a human gastric adenocarcinoma cell line. METHODS: We evaluated cell growth inhibitory and mechanical properties of the cytoplasmic membrane and the downregulation of survivin and proinflammatory genes in AGS cells treated with SBS after 24 and 48 h. RESULTS: SBS significantly inhibits the AGS cell growth, and the concentrations with IC50 values after 24 and 48 h treatments are measured as 2266 and 1956 µg/mL, respectively. Regarding the AFM images and Young`s modulus analysis, SBS significantly induces morphological changes in the cytoplasmic membrane of the treated AGS cells. Expression of survivin, NFƙB, and IL-8 genes is significantly suppressed in AGS cells treated with SBS. CONCLUSIONS: Considering the antitumor activities of SBS on AGS cell line, it can be regarded as a prospective therapeutic and preventive strategy against human stomach cancer disease.

ACE2-Inhibitory Effects of Bromelain and Ficin in Colon Cancer Cells.

Background and Objectives: Bromelain and ficin are aqueous extracts from fruits of Ananas comosus and Ficus carcia plants, used widely for medical applications. Angiotensin-converting enzyme 2 (ACE2) is a homolog of ACE, degrading Ang II to angiotensin 1-7 and decreasing the cellular concentration of Ang II. Materials and Methods: In this study, we investigated the ACE2-inhibitory, antiproliferative, and apoptosis-inducing effects of ficin and bromelain on caco-2 cells. Results: We found that bromelain and ficin significantly reduced the viability of human colon cancer cells with IC50 value concentrations of 8.8 and 4.2 mg/mL for bromelain after 24 and 48 h treatments, and 8.8 and 4.2 mg/mL for ficin after 24 and 48 h treatments, respectively. The apoptosis of the caco-2 cell line treated with bromelain was 81.04% and 56.70%, observed after 24 and 48 h. Total apoptotic proportions in caco-2 cells treated with ficin after 24 and 48 h were 83.7% and 73.0%. An amount of 1.6 mg/mL of bromelain and ficin treatments on caco-2 cells after 24 h revealed a higher decrease than that of other concentrations in the expression of ACE2 protein. Conclusions: In conclusion, bromelain and ficin can dose-dependently decrease the expression of ACE2 protein in caco-2 cells.

Molecular Mechanisms of Shigella Pathogenesis; Recent Advances.

Shigella species are the main cause of bacillary diarrhoea or shigellosis in humans. These organisms are the inhabitants of the human intestinal tract; however, they are one of the main concerns in public health in both developed and developing countries. In this study, we reviewed and summarised the previous studies and recent advances in molecular mechanisms of pathogenesis of Shigella Dysenteriae and non-Dysenteriae species. Regarding the molecular mechanisms of pathogenesis and the presence of virulence factor encoding genes in Shigella strains, species of this bacteria are categorised into Dysenteriae and non-Dysenteriae clinical groups. Shigella species uses attachment, invasion, intracellular motility, toxin secretion and host cell interruption mechanisms, causing mild diarrhoea, haemorrhagic colitis and haemolytic uremic syndrome diseases in humans through the expression of effector delivery systems, protein effectors, toxins, host cell immune system evasion and iron uptake genes. The investigation of these genes and molecular mechanisms can help us to develop and design new methods to detect and differentiate these organisms in food and clinical samples and determine appropriate strategies to prevent and treat the intestinal and extraintestinal infections caused by these enteric pathogens.

A quantitative prevalence of Escherichia coliO157 in different food samples using real-time qPCR method.

Escherichia coli serogroup O157 is the main causative agent of several intestinal and extra-intestinal foodborne diseases in humans through consumption of low-dose contaminated foods such as milk, beef, and vegetables. To date, studies regarding the quantitative prevalence of E. coli O157 in foods are so limited. Therefore, this study aimed to evaluate the quantitative prevalence rate of E. coli serogroup O157 in raw milk (n = 144), vegetable salad (n = 174), and minced beef samples (n = 108) using the real-time qPCR SYBR green melting curve method targeting the rfbA gene. First, we evaluated the method and found a sensitive and specific qPCR assay with 1 log of CFU/ml detection limit to detect E. coli O157 (Tm = 80.3 ± 0.1°C). About 2.77%, 10.18%, and 9.19% of raw milk, minced beef, and vegetable salad samples, respectively, were contaminated with E. coli O157. Minced beef and vegetable salad samples were significantly more contaminated than raw milk samples. Population average of E. coli O157 in raw milk, minced beef, and vegetable salad samples were 2.22 ± 0.57, 3.30 ± 0.40, and 1.65 ± 0.44 log CFU/ml or gr, respectively. Significantly higher levels of population of E. coli O157 were observed in minced beef samples. Minced beef can be regarded as the main food in the transmission of this foodborne pathogen. Routine quantitative rapid monitoring is strongly suggested to be carried out to prevent foodborne diseases caused by E. coli O157.

Antimicrobial susceptibility, virulence genes and genomic characterization of Trueperella pyogenes isolated from abscesses in dairy cattle.

Trueperella pyogenes is an opportunistic animal pathogen mainly associated with various suppurative infections in wild and domestic animals. Limited studies have investigated the pathogenesis of diseases caused by this pathogen. The main objective of the current study was to investigate the prevalence, phenotypic properties, virulence genotypes, antimicrobial susceptibility and genetic characterization of T. pyogenes isolated from abscess lesions in different tissues of on-farm dairy cattle. The study was performed on 150 postpartum cattle with clinical abscess symptoms on 22 farms around Tehran, Iran. Classical and disk diffusion methods are used for phenotypic characterization and antibiotic susceptibility. Detection of virulence factor encoding genes and genomic characterization of the isolates also are carried out by conventional PCR and BOX-PCR assays, respectively. Sixty-eight T. pyogenes strains (45.3%) were isolated, 12 were identified as pure cultures and the other 56 strains were isolated from mixed cultures. Seven distinct biotypes were identified among the T. pyogenes isolates. The isolates were mostly resistance to trimethoprim-sulfamethoxazole (70.6%), erythromycin (36.7%), tetracycline (26.5%) and tylosin (23.5%) antibiotics. Also, the genes plo, nanH, nanP and fimA were detected in all isolates. Forty-two isolates (61.7%) carried all virulence factor genes detected in this study. Three isolates only carried plo, nanH, nanP and fimA genes were identified as the least frequent genotype. All sixty-eight isolates and the reference strain were categorized into seven main clusters (A-G). A strong association was observed between virulence factor encoding genes, pathogenicity and biochemical biotypes in some specific clonal relationships.

Anticancer Properties of Saccharomyces boulardii Metabolite Against Colon Cancer Cells.

Saccharomyces cerevisiae var. boulardii has been used as a probiotic yeast in the medical and food industries. Colon cancers have been known as the third most common cancer type worldwide. Nowadays, cell-free extract and metabolites of probiotics have been employed for the treatment or prevention of different cancer diseases. This study investigates the anticancer properties of S. boulardii metabolites against human colon carcinoma. We evaluated cytotoxicity, apoptosis induction, and suppression of survivin, IL-8, and NFƙB gene expression effects of SBM against caco-2 cells after 24 and 48 h. IC50 concentrations of SBM were measured at 815 and 1411 µg/mL for 24 and 48 h treatments, respectively. The total proportion of apoptotic caco-2 cells treated with SBM after 24 and 48 h were calculated at 62.23 and 88.7%, respectively. Also, relative expression of survivin, IL-8, and NFƙB genes were significantly suppressed in caco-2 cells treated with SBM after 24 and 48 h. In conclusion, we found that SBM induced apoptosis, inhibited the growth rate, and suppressed the expression of the survivin, IL-8, and NFƙB genes in human colorectal cancer cells and it can be considered as a perspective supplement or drug for the treatment or prevention of colon cancer in humans.

Prevalence of foodborne and zoonotic viral pathogens in raw cow milk samples.

Foodborne and zoonotic viral pathogens are responsible for substantial morbidity and mortality worldwide. These viruses can be transmitted through foods such as dairy products to humans and cause several acute and chronic diseases. This study aimed to investigate the prevalence and profile of different foodborne and zoonotic viruses in raw cow milk samples. We collected 492 raw cow milk samples from local dairy markets in Qazvin, Iran. Then we evaluated the presence of hepatitis A virus, noroviruses, rotavirus, astrovirus, bovine leukaemia virus (BLV) and tick-borne encephalitis virus (TBEV) in samples using conventional and nested reverse transcription-polymerase chain reaction methods. We found that 34.95, 7.72, 25.81, 14.63, 66.86, 12.80 and 21.34% of raw milk samples were contaminated with norovirus GI, norovirus GII, hepatitis A virus, rotavirus, astrovirus, BLV and TBEV viruses, respectively. Interestingly, the samples collected from the city's south area revealed a higher prevalence of foodborne and zoonotic viruses. Astrovirus and its combination with norovirus GI were the most prevalent virus profiles. Also, the highest correlations were observed among the presence of rotavirus and hepatitis A viruses (0.36) and TBEV and norovirus GII (0.31). Considering the prevalence rate and virus profiles of different foodborne and zoonotic viruses in raw milk samples, hygiene practices and the pasteurization process are strongly suggested to be conducted throughout the cow milk production chain and in dairy industries to prevent infections with these pathogens.

Molecular dynamics simulations, molecular docking, and kinetics study of kaempferol interaction on Jack bean urease: Comparison of extended solvation model.

Since the urease enzyme creates gastric cancer, peptic ulcer, hepatic coma, and urinary stones in millions of people worldwide, it is essential to find strong inhibitors to help patients. Natural products are well known for their beneficial effects on health and efforts are being made to isolate the ingredients, the so-called flavonoids. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, and cosmetic applications. Kaempferol (KPF) is an antioxidant found in many fruits and vegetables. Many reports have explained the significant effects of dietary KPF in reducing the risk of chronic diseases such as cancer, ischemia, stroke, and Parkinson's. The current study aimed at investigating the inhibitory impact of KPF on Jack bean urease (JBU) using molecular dynamics (MD) simulations and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations to confirm the results obtained from isothermal titration calorimetry (ITC), extended solvation model, and docking software. In addition, UV-VIS spectrophotometry was used to study the kinetics of urease inhibition. Calorimetric and spectrophotometric determinations of the kinetic parameters of this inhibition indicate the occurrence of a reversible and noncompetitive mode. Also, the docking and MD results indicated that the urease had well adapted to the kaempferol in the binding pocket, thereby forming a stable complex. Kaempferol displayed low binding energy during MMPBSA calculations. The inhibitory potential of kaempferol was confirmed by experimental and simulation data, but in vivo investigations are also recommended to validate our results.

Morganella Morganii Infection in Hirudo Medicinalis (Iran): A Case Report.

Medicinal leeches (Hirudo medicinalis) are used in surgical and non-surgical manners. Morganella morganii is an opportunistic and zoonotic pathogenic bacterium causing serious clinical complications. In this study, we isolated, discovered and characterized M. morganii-infected H. medicinalis. We detected and identified M. morganii in all inflamed and swollen Hirudo medicinalis samples. The 16S rRNA sequence of the isolates confirmed all strains of M. morganii. All strains were sensitive to Ceftriaxone, Ceftiofur, Danofloxacin, Ciprofloxacin, Enrofloxacin, Oxytetracycline, and Meropenem and were resistant to Erythromycin, Amoxicillin, Ampicillin, Cefazolin, Colistin, Penicillin G, and Lincomycin. This pathogenic bacterium is a zoonotic pathogen, and monitoring the prevalence rate of this bacteria is strongly necessary for leeches used in human medical treatment and care. Finally, all infected leeches were treated successfully in this case report study.

Activation of apoptosis and G0/G1 cell cycle arrest along with inhibition of melanogenesis by humic acid and fulvic acid: BAX/BCL-2 and Tyr genes expression and evaluation of nanomechanical properties in A375 human melanoma cell line.

Objectives: Humic acid (HA) and Fulvic acid (FA) are major members of humic substances, which are extracted from organic sources including soil and peat. The pro-apoptotic and anti-melanogenic effects of HA and FA at the cellular and molecular levels in the A375 human melanoma cell line were examined in this study. Materials and Methods: The cytotoxicity effect of HA and FA were evaluated by cell viability assay. Apoptosis and cell cycle were investigated by flow cytometry. Real-time PCR was carried out to measure the expression of BAX, BCL-2, and Tyr genes. Moreover, the changes in nanomechanical properties were determined through atomic force microscopy (AFM). Results: It was found that HA and FA decrease cell viability with an IC50 value of 50 µg/ml (dose-dependent) for 14 hr, arrested cells in the G0/G1 phase, and increased the sub-G1 phase (induce apoptosis). Based on the AFM analysis, Young's modulus and adhesion force values were increased, also ultrastructural characteristics of cells were changed. Results of Real-time PCR revealed that HA and FA lead to a decrease in the expressions of BCL-2 and Tyr genes, and increase the BAX gene expression. Conclusion: These results exhibited that HA and FA possess pro-apoptotic effects through increasing the BAX/ BCL-2 expression in A375 cells. These molecular reports were confirmed by cellular nanomechanical assessments using AFM and flow cytometry. In addition, HA and FA inhibited melanogenesis by decreasing the expression of the Tyr gene. It is worthwhile to note that, HA and FA can be regarded to design new anti-cancer and anti-melanogenesis products.

Antibiotic Resistance and Molecular Characterization of Cronobacter sakazakii Strains Isolated from Powdered Infant Formula Milk.

BACKGROUND: Cronobacter sakazakii is a new emerging foodborne bacterial pathogen associated with severe lethal diseases such as meningitis, necrotizing enterocolitis, and septicemia in infants and neonates. Powdered infant formula milk (PIFM) has been recognized as one of the main transmission vehicles and contaminated sources of this pathogen. This study aimed to investigate the prevalence rate, genotypic and phenotypic antibiotic resistance profile, and clonal relatedness of C. sakazakii strains isolated from 364 PIFM samples collected from Tehran city, Iran. METHODS: Culture-based methods, Kirby-Bauer disk diffusion antibiotic resistance testing, conventional Polymerase Chain Reaction (PCR), and Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) assays were used in this study to detect and characterize the C. sakazakii isolates. RESULTS: We isolated 25 C. sakazakii strains from PIFM samples (6.86%). The isolates were highly resistant to amoxicillin-clavulanic acid, amoxicillin, ampicillin, cefoxitin, cefepime, erythromycin, ceftriaxone, ciprofloxacin, and chloramphenicol and susceptible to gentamicin, tetracycline, norfloxacin, and azithromycin antibiotics. The blaCTX-M-1 gene was detected in 96% of the isolates. The isolates were categorized into eight distinct clonal types using the ERIC-PCR method, showing a high genetic diversity among the isolates. However, there was a significant correlation between the genotypic and phenotypic antibiotic resistance properties of the isolates. CONCLUSIONS: Novel microbial surveillance systems for detecting multi-drug-resistant C. sakazakii are required to control the contamination of this foodborne pathogen in infant foods.

Phylogenetic analysis and antibiotic resistance of Shigella sonnei isolates.

Shigellosis is one of the most important gastric infections caused by different species of Shigella, and has been regarded as a serious threat to public health. Lineage/sublineage profile of Shigella sonnei is strongly associated with the antibiotic resistance and population structure of this pathogen. In this study, we determined the phylogeny and antibiotic resistance profiles of S. sonnei strains, isolated from 1246 stool and 580 food samples, using multiplex PCR-HRMA genotyping and Kirby-Bauer disk diffusion methods, respectively. A total of 64 S. sonnei strains were isolated (13 food and 51 clinical isolates). Multiplex PCR-HMR assay was able to differentiate the lineages II and III, and sublineages IIIb and IIIc strains successfully considering the definite melting curves and temperatures. Lineage I and sublineage IIIa strain were not isolated in this study. We also demonstrated that most of the S. sonnei strains isolated from both food and clinical samples clustered within the lineage III and sublineage IIIc. Resistance against trimethoprim-sulfamethoxazole, tetracycline, chloramphenicol, and streptomycin antibiotics were the most prevalent phenotypes among the S. sonnei lineage III and sublineage IIIc strains.

Prevalence, Antibiotic Resistance, Toxin-Typing and Genotyping of Clostridium perfringens in Raw Beef Meats Obtained from Qazvin City, Iran.

BACKGROUND: Clostridium perfringens is one of the highest prevailing spore-forming foodborne pathogens, which is widely distributed and causes severe disease and outbreaks in humans and animals. Raw meat and poultry are the main vehicles of this pathogen. In this study, we investigated the prevalence, antibiotic resistance pattern, toxin-encoding genes and genetic diversity of C. perfringens isolates from raw whole and minced meat samples purchased from local markets in Qazvin city, Iran (the source of beef cattle production was also located in Qazvin city, Iran). METHODS: We used conventional culture-based and Kirby-Bauer disk diffusion and conventional and arbitrary primer PCR methods. RESULTS: A total of 18 C. perfringens strains were isolated from 133 raw meat samples (13.53%). Up to 44.4 and 55.5% of these isolates were detected in raw minced and whole meat samples, respectively. We found that 72.2, 66.6, 61.1, 37.8 and 33.3% of the C. perfringens isolates were resistant to ampicillin, tetracycline, amoxicillin, ciprofloxacin and chloramphenicol antibiotics, respectively. Multidrug resistance was found in 38% of the isolates. Among the four main toxin genes evaluated, the Cpa gene was detected in all isolates, and 61.1% of the isolates were mostly recognized as type A C. perfringens. High levels of genetic diversity were observed among the isolates, and they were classified into five distinct groups. CONCLUSIONS: The isolates from whole meat samples were more resistant to antibiotics. However, toxin genes were more detected in the isolates from minced meat samples. Our findings suggest that contamination of raw meat products with multidrug resistant C. perfringens could be regarded as one of the concerning pathogens in these products. Comprehensive monitoring of C. perfringens isolates is strongly recommended.

Expression of virulence factor genes in co-infections with Trueperella pyogenes isolates and other bacterial pathogens; an in vivo study.

Trueperella pyogenes is an opportunistic bacterial pathogen causing several infectious diseases, including metritis, mastitis and abscesses in domestic animals such as dairy cattle. Several virulence proteins are released by T. pyogenes strains contributing to the pathogenic and causing disease potential of this pathogen. So far, many aspects of T. pyogenes pathogenesis are unknown. In this study, expression levels of plo, fimA, nanH and cbpA genes encoding pyolysin, fimbriae, neuraminidase and collagen-binding protein, respectively in T. pyogenes isolated from totally 15 metritis, mastitis and cutaneous abscesses convenience samples in response to co-culture with other pathogens including E. coli, St. dysgalactiae, S. aureus, F. necrophorum and L. plantarum strains in mice study model have been investigated. We found that expression levels of plo, fimA, nanH and cbpA genes in T. pyogenes isolates in response to co-culture with F. necrophorum and E. coli were significantly increased; however, no significant changes was seen in the level of expression of these genes in the isolates in response to co-culture with St. dysgalactiae and S. aureus. Notably, expression of all virulence factor genes was suppressed in T. pyogenes in response to co-culture with L. plantarum. We observed that L. plantarum might be used to prevent infectious diseases caused by T. pyogenes.

FTIR differentiation based on genomic DNA for species identification of Shigella isolates from stool samples.

Shigellosis is one of the major public health concerns in developing and low-income countries caused by four species of Shigella. There is an apparent need to develop rapid, cost-effective, sensitive and specific methods for differentiation of Shigella species to be used in outbreaks and health surveillance systems. We developed a sensitive and specific Fourier-transform infrared spectroscopy (FTIR) based method followed by principal component analysis (PCA) and hierarchical clustering analysis (HCA) assays to differentiate four species of Shigella isolates from stool samples. The FTIR based method was evaluated by differentiation of 91 Shigella species from each other in clinical samples using both gold standards (culture-based and agglutination methods) and developed FTIR assay; eventually, the sensitivity and specificity of the developed method were calculated. In summary, four distinct FTIR spectra associated with four species of Shigella were obtained with wide variations in three definite regions, including 1800-1550 cm-1, 1550-1100 cm-1, and 1100-800 cm-1 distinguish these species from each other. In this study, we found the FTIR method followed by PCA analysis with specificity, sensitivity, differentiation error and correct differentiation rate values of 100, 100, 0 and 100%, respectively, for identification and differentiation of all species of the Shigella in stool samples.

Essential Oils from Indigenous Iranian Plants: A Natural Weapon vs. Multidrug-Resistant Escherichia coli.

Aim of this study was to investigate the antimicrobial properties of herbal plant essential oils (EOs) from selected Iranian plant species such as Ferulago angulata, Zataria multiflora, Cuminum cyminum, and Mentha longifolia against antibiotic-resistant Escherichia coli (E. coli) strains. For this purpose, the Escherichia coli strains, isolated from raw cow's milk and local dairy products (yogurt, cream, whey, cheese, and confectionery products) collected from different areas of Hamedan province, Iran, were investigated for their resistance to antibiotics (i.e., streptomycin, tetracycline, gentamicin, chloramphenicol, ciprofloxacin, and cefixime). Thus, the E. coli strains were tested for their susceptibility to the above-mentioned essential oils. Regarding antibiotics, the E. coli strains were highly sensitive to ciprofloxacin. In relation to essential oils, the most effective antibacterial activity was observed with Zataria multiflora; also, the bacteria were semi-sensitive to Cuminum cyminum and Mentha longifolia essential oils. All strains were resistant to Ferulago angulata essential oil. According to the results, the essential oil of Zataria multiflora can be considered as a practical and alternative antibacterial strategy to inhibit the growth of multidrug-resistant E. coli of dairy origin.