scholarly journals A sampling survey of enterococci within pasteurized, fermented dairy products and their virulence and antibiotic resistance properties

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254390
Author(s):  
Solomon H. Mariam
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Target Genes ◽  
Hydrolytic Activity ◽  
Fermented Foods ◽  
Species Identity ◽  
Traditional Practice ◽  
Antibiotic Resistant ◽  
Select Group ◽  
Antibiotic Resistance Properties

Globally, fermented foods (FFs), which may be traditional or industrially-produced, are major sources of nutrition. In the traditional practice, the fermentation process is driven by communities of virtually uncharacterized microflora indigenous to the food substrate. Some of these flora can have virulent or antibiotic resistance properties, posing risk to consumers. Others, such as Enterococcus faecalis and Enterococcus faecium, may also be found in such foods. Enterococci that harbor antibiotic resistance or virulence factors can cycle among animals, food, humans and the environment, thereby transferring these harmful properties at the gene level to harmless commensals in the food matrix, animals and humans. In this work, several microbial isolates obtained from different FF sources were analyzed for their identity and virulence and/or antibiotic resistance properties. For identification aiming at enterococci, isolates that were Gram-positive and catalase- and oxidase-negative were subjected to multiple tests including for growth in broth containing 6.5% NaCl, growth and hydrolytic activity on medium containing bile-esculin, hemolytic activity on blood agar, and growth at 45°C and survival after incubation at 60°C for 30 min. Furthermore, the isolates were tested for susceptibility/resistance to a select group of antibiotics. Finally, the isolates were molecularly-characterized with respect to species identity and presence of virulence-encoding genes by amplification of target genes. Most sources contained enterococci, in addition to most of them also containing Gram-negative flora. Most of these also harbored virulence factors. Several isolates were also antibiotic-resistant. These results strongly suggest attention should be given to better control presence of such potentially pathogenic species.

scholarly journals Investigation of Some Antibiotic Resistance Genes of Indigenous Lactobacilli Isolated From Traditional Yogurt In Zanjan Province of Iran

2021 ◽  
Author(s):  
Bahare Moghimi ◽  
Maryam Ghobadi Dana ◽  
Reza Shapouri
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Food Chain ◽  
Starter Culture ◽  
Antibiotic Resistance Genes ◽  
Molecular Methods ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Fermented Foods ◽  
Antibiotic Resistant

Abstract Purpose: Given the increasing use of antibiotics on humans and livestock for treatment or as a growth stimulant, antibiotic resistance has become a general concern. The food chain and specially fermented foods could be a source of antibiotic-resistant bacteria and resistance genes. Lactic Acid Bacteria (LAB) and Lactobacilli are considered safe to use as starter culture or probiotic strains. Recently, however, antibiotic-resistant genes isolated from LABs showed the necessity of setting international regulations to reduce the risk of antibiotic resistance genes transmission via the food chain. The current study aimed to investigate the antibiotic resistance of Lactobacilli isolated from traditional yogurt samples from Zanjan province in Iran.Methods: Lactobacilli characterization and identification were carried out through biochemical and molecular methods. The disk diffusion method was applied to determine phenotype resistance using 13 antibiotic disks resistance genes presence were investigated in the isolates to determine transferability risk, respectively.Results: Based on biochemical and molecular methods, 24 isolates have been identified as Lactobacilli with multiple antibiotic-resistant phenotypes. Vancomycin resistance was a typical phenotype and genotype among isolates. On investigated Lactobacilli chromosome, Tetracycline resistance genes Chloramphenicol (cat), beta-lactam, aminoglycosides (aph (3’)-III), and aadA resistance genes have been detected. While the examined resistance genes have not been detected on the plasmids, they were all on the bacterial chromosome.Conclusion: The results showed that the investigated isolates did not carry the resistance genes on their plasmids. It, therefore, would be a good point since they probably do not transfer resistance genes to other bacteria, and they would be proper candidates to do more investigation for introducing new safe starter culture or probiotic strain to food industries.

Phage-mediated dissemination of virulence factors in pathogenic bacteria facilitated by antibiotic growth promoters in animals: a perspective

2017 ◽  
Vol 18 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Migma Dorji Tamang ◽  
Hoon Sunwoo ◽  
Byeonghwa Jeon
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Growth Promotion ◽  
Bacterial Species ◽  
Agricultural Practice ◽  
Growth Promoters ◽  
Antibiotic Resistant ◽  
The World ◽  
Antibiotic Growth Promoters

AbstractAddition of sub-therapeutic antibiotics to the feed of food-producing animals for growth promotion and disease prevention has become a common agricultural practice in many countries. The emergence of antibiotic-resistant pathogens is a looming concern associated with the use of antibiotic growth promoters (AGPs) around the world. In addition, some studies have shown that AGPs may not only affect antibiotic resistance but may also stimulate the dissemination of virulence factors via bacteriophages. Although only a few studies are currently available in the literature regarding this topic, in this article we endeavor to provide a perspective about how AGPs would impact the transmission of virulence factors by horizontal gene transfer via phages in a few pathogenic bacterial species significant to livestock production.

scholarly journals Proteomic Characterization of Antibiotic Resistance, and Production of Antimicrobial and Virulence Factors in Streptococcus Species Associated with Bovine Mastitis. Could Enzybiotics Represent Novel Therapeutic Agents Against These Pathogens?

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 302 ◽  
Author(s):  
Ana G. Abril ◽  
Mónica Carrera ◽  
Karola Böhme ◽  
Jorge Barros-Velázquez ◽  
José-Luis R. Rama ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Research Work ◽  
Bovine Mastitis ◽  
Mass Spectrometry Analysis ◽  
Resistant Bacteria ◽  
Toxic Substances ◽  
Antibiotic Resistant ◽  
Spectrometry Analysis ◽  
Species Specific

Streptococcus spp. are major mastitis pathogens present in dairy products, which produce a variety of virulence factors that are involved in streptococcal pathogenicity. These include neuraminidase, pyrogenic exotoxin, and M protein, and in addition they might produce bacteriocins and antibiotic-resistance proteins. Unjustifiable misuse of antimicrobials has led to an increase in antibiotic-resistant bacteria present in foodstuffs. Identification of the mastitis-causing bacterial strain, as well as determining its antibiotic resistance and sensitivity is crucial for effective therapy. The present work focused on the LC–ESI–MS/MS (liquid chromatography–electrospray ionization tandem mass spectrometry) analysis of tryptic digestion peptides from mastitis-causing Streptococcus spp. isolated from milk. A total of 2706 non-redundant peptides belonging to 2510 proteins was identified and analyzed. Among them, 168 peptides were determined, representing proteins that act as virulence factors, toxins, anti-toxins, provide resistance to antibiotics that are associated with the production of lantibiotic-related compounds, or play a role in the resistance to toxic substances. Protein comparisons with the NCBI database allowed the identification of 134 peptides as specific to Streptococcus spp., while two peptides (EATGNQNISPNLTISNAQLNLEDKNK and DLWC*NM*IIAAK) were found to be species-specific to Streptococcus dysgalactiae. This proteomic repository might be useful for further studies and research work, as well as for the development of new therapeutics for the mastitis-causing Streptococcus strains.

scholarly journals Phenotypic and genotypic evaluation of antibiotic resistance and molecular characterization of Streptococcus species isolated from hospital cockroaches

2020 ◽  
Author(s):  
Mohammad Chehelgerdi ◽  
Reza Ranjbar
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Bacterial Culture ◽  
Antibiotic Resistance Genes ◽  
Pcr Amplification ◽  
Hospital Environment ◽  
Streptococcus Species ◽  
Antibiotic Resistance Properties

Abstract Background The present investigation aimed to assess the antibiotic resistance properties and distribution of virulence factors in the Streptococcus spp. isolated from hospital cockroaches. Methods Six-hundred and sixty cockroach samples were collected. Cockroaches were vigorously washed with normal saline, and the achieved saline was used for bacterial culture. Isolated Streptococcus spp. were subjected to disk diffusion as well as PCR amplification of virulence factors and antibiotic resistance genes. Results Prevalence of S. pyogenes, S. agalactiae and S. pneumonia was 4.82%, 1.66% and 6.96%, respectively. The highest prevalence of S. pyogenes, S. agalactiae and S. pneumonia were found in oriental (5.71%), oriental (2.85%) and American (7.71%) cockroaches, respectively. Cfb (53.93%), cyl (52.8%), scaa (51.68%) and glna (50.56%) were the most commonly detected streptococcal virulence factors. Pbp2b (71.91%), pbp2 × (58.42%), mefA (46.06%), ermB (46.06%) and tetM (46.06%) were the most commonly detected antibiotic resistance genes. Streptococcal spp. exhibited the highest prevalence of resistance against tetracycline (80.89%), trimethoprim (65.16%), and penicillin (56.17%). Conclusion To the best of our knowledge, this is the first prevalence report of virulence factors and antibiotic resistance genes in the Streptococcal spp. isolated from American, German and oriental hospital cockroaches. Findings recommended a certain role for cockroaches in the transmission of nosocomial infections and particularly those caused by virulent and resistant Streptococcus spp. in the hospital environment.

scholarly journals Sublethal β-lactam antibiotics induce PhpP phosphatase expression and StkP kinase phosphorylation in PBP-independent β-lactam antibiotic resistance ofStreptococcus pneumoniae

2018 ◽  
Author(s):  
Yan-Ying Huang ◽  
Yan-Hong Sun ◽  
Peng Du ◽  
Xiao-Xiang Liu ◽  
Jie Yan ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pneumoniae ◽  
Gene Knockout ◽  
Hydrolytic Activity ◽  
Signal Molecules ◽  
Human Populations ◽  
Antibiotic Resistant ◽  
Lactam Antibiotic ◽  
In The Wild ◽  
High Level

AbstractStkP and PhpP ofStreptococcus pneumoniaehave been confirmed to compose a signaling couple, in which the former is a serine/threonine (Ser/Thr) kinase while the latter was annotated as a phosphotase. StkP has been reported to be involved in penicillin-binding protein (PBP)-independent penicillin resistance ofS. pneumoniae. However, the enzymatic characterization of PhpP and the role of PhpP in StkP-PhpP couple remain poorly understood. Here we showed that 1/4 minimal inhibitory concentration (MIC) of penicillin (PCN) or cefotaxime (CTX), the representatives of β-lactam antibiotics, could induce the expression ofstkPandphpPgenes and phosphorylation of StkP in PCN/CTX-sensitive strain ATCC6306 and three isolates ofS. pneumoniae(MICs: 0.02-0.5 μg/ml). The product ofphpPgene hydrolyzed PP2C type Ser/Thr phosphotase-specific RRA(pT)VA phosphopeptide substrate with the Km and Kcat values of 277.35 μmol/L and 0.71 S−1, and the hydrolytic activity was blocked by sodium fluoride, a PP2C type Ser/Thr phosphatase inhibitor. The phosphorylation levels of StkP in the fourphpPgene-knockout (ΔphpP) mutants were significantly higher than that in the wild-type strains. In particular, the MICs of PCN and CTX against the ΔphpPmutants were significantly elevated as 4-16 μg/ml. Therefore, our findings confirmed that sublethal PCN and CTX act as environmental inducers to cause the increase ofphpPandstkPgene expression and StkP phosphorylation. PhpP is a PP2C type Ser/Thr protein phosphatase responsible for dephosphorylation of StkP. Knockout of thephpPgene results in a high level of StkP phosphorylation and PBP-independent PCN/CTX resistance ofS. pneumoniae.ImportanceStreptococcus pneumoniaeis a common pathogen in human populations in many countries and areas due to the prevalence of β-lactam antibiotic-resistant pneumococcal strains. Production of β-lactamases and mutation of penicillin-binding proteins (PBP) have been considered as the major β-lactam antibiotic-resistant mechanisms in bacteria, butS. pneumoniaehas not been confirmed to produce any β-lactamases and many pneumococcal strains present PBP mutation-independent β-lactam antibiotic resistance. StkP is a Ser/Thr kinase ofS. pneumoniaeto compose a signal-couple with PhpP protein. The present study demonstrated that the PhpP is a PP2C-type phosphotase for dephosphorylation of StkP and the sublethal penicillin (PCN) or cefotaxime (CTX) acted as environmental signal molecules to induce the expression of PhpP. The knockout of PhpP-encoding gene caused the PCN/CTX resistance generation of PCN/CTX-sensitive pneumococcal strains. All the data indicate that StkP-PhpP couple ofS. pneumoniaeis involved in PBP mutation-independent β-lactam antibiotic resistance by phosphorylation of StkP.

Vegetables and Restaurant Salads as a Reservoir for Shiga Toxigenic Escherichia coli: Distribution of Virulence Factors, O-Serogroups, and Antibiotic Resistance Properties

2016 ◽  
Vol 79 (7) ◽  
pp. 1154-1160 ◽  
Author(s):  
AMIR SHAKERIAN ◽  
EBRAHIM RAHIMI ◽  
PARDIS EMAD
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Close Contact ◽  
Polluted Water ◽  
E Coli ◽  
Vegetable Samples ◽  
Total Prevalence ◽  
Significant Difference ◽  
Antibiotic Resistance Properties

ABSTRACT Close contact of vegetables with soil, polluted water, and animal manure and unsanitary conditions during processing of restaurant salads led us to study the distribution of virulence factors, O-serogroups, and antibiotic resistance properties in Shiga toxigenic Escherichia coli (STEC) isolated from vegetables and salads. Samples of vegetables and salad (n =420) were collected and evaluated for the presence of E. coli using culture and a PCR assay. Total prevalence of E. coli in studied samples was 49.5%. E. coli was found in 49.6% of vegetable samples and 49% of salad samples. Leek and traditional salad had the highest incidence of E. coli. Significant differences in the incidence of E. coli were found between the hot and cold seasons. Of the 149 E. coli isolates from vegetable samples, 130 (87%) were STEC, and of the 59 E. coli isolates from salad samples, 50 (84%) were STEC. The most commonly detected virulence factors were stx1 and eaeA. A significant difference was found between the frequency of the attaching and effacing and the enterohemorrhagic E. coli subtypes. Serogroups O26 (46% of isolates), O157 (14%), O121 (10%), and O128 (9%) were the most commonly detected serogroups among the STEC strains. The tetA, sul1, aac(3)-IV, dfrA1, blaSHV, and CITM antibiotic resistance genes were found in 96, 47.7, 90, 51, 27, and 93% of isolates, respectively. The highest levels of resistance were found against ampicillin (96.6% of isolates), tetracycline (87%), and gentamicin (90%). This study shows the importance of vegetables and salads as potential sources of E. coli infection.

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