scholarly journals Molecular screening of the entA gene of Enterococcus faecium isolated from Food and clinical sources

2020 ◽  
Vol 14 (1) ◽  
pp. 79-85
Author(s):  
Andalus Sabah Atiyah ◽  
Marwa H. ALKhafaji

Background: The microbial production of substances that have the potency to suppress the growth of other microorganisms is probably one of the prevalent defense strategy developed in nature, microorganisms produce a variable bunch of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. Objective: The purpose of the present study was to isolate and identify Enterococcus faecium isolates then detecting its ability of carrying the gene responsible for enterocin production in this species. Materials and methods: Out of 50 samples from different sources (food and clinical sources) were collected for the Enterococcus faecium isolation, and the isolated bacteria Enterococcus faecium (37) isolates were detected for their harboring of Enterocin A gene (entA), using conventional PCR technique. Results: The identification revealed that 37(74%) isolates were considered as Enterococcus faecium, 20 isolates (54.05%) out of food samples (10 samples were collected from dairies, 7 from vegetables and 3 from fish samples), and 17 isolates 45.9% out of clinical samples (11 from stool and 6 from urine source). Genotypic Detection done by the amplification of the enterocin coding gene (ent A),  and the results revealed that all the isolates were harboring that gene despite of the phonotypical differences, that they amplified entA gene and the PCR product size (362 bp) was detected using agarose gel electrophoresis. Conclusions: This study indicates the presence of Enterococcus spp. in food and clinical sources and the ability of these bacteria to produce antibacterial substances which is active against closely related clinical isolates.

2020 ◽  
pp. 3164-3171
Author(s):  
Andalus S. Atiyah ◽  
Marwa H. Alkhafaji

The microbial production of substances that have the ability to inhibit the growth of other microorganisms is possibly the most common defense strategy developed in nature. Microorganisms produce a variable collection of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. The aim of the present study was to isolate and identify Enterococcus spp. and  its most prevalent species from food samples and determine its antibacterial activity against Staphylococcus aureus isolates. A total of 50 food samples from different sources (dairy products (20 samples) and vegetables and fish (15 samples each)) were collected from different local markets in Baghdad and cultured. Enterococcus spp were isolated from only 32 food samples. E. faecium was the most predominant species which was recovered from 20 samples (62.5 %), 10 dairies, 7 vegetables, and 2 fish. E. faecalis was found in 8 samples (25 %), 5 vegetables and 3 fish.  E. avium was recovered 6.25% as well as E. gallinarium (2 samples for each) Enterococcus avium were all isolated from dairy products but Enterococcus gallinarium one sample isolated from dairies and the other from fish. This study indicates the presence of Enterococcus spp. in the food samples and the ability of these bacteria to produce antibacterial substances which are active against closely related clinical isolates.


1999 ◽  
Vol 62 (10) ◽  
pp. 1103-1110 ◽  
Author(s):  
JER-SHENG LIN ◽  
HAU-YANG TSEN

Salmonella Typhimurium is one of the most important Salmonella serovars that may cause foodborne disease and human salmonellosis infection. Detection of this organism in the clinical samples of persons with gastroenteritis and the food samples associated with such persons may allow us to trace the cause of disease. Because malic acid dehydrogenase, an enzyme of the citric acid cycle, is common to organisms, the gene (mdh) coding for this enzyme was selected for the design of Salmonella Typhimurium-specific polymerase chain reaction (PCR) primers. By comparison of the mdh gene sequences of Salmonella Typhimurium and other Salmonella serotypes and of some isolates of other genera, two oligonucleotides were designed and used as PCR primers for the specific detection of Salmonella Typhimurium. The molecular weight of the PCR product was 261 bp as expected. Salmonella serovars other than Salmonella Typhimurium and isolates of other genera in the Enterobacteriaceae that is closely related to Salmonella did not generate any false-positive results. When this primer pair was used for the detection of Salmonella Typhimurium cells artificially inoculated into human stool specimens and food samples, such as milk and raw chicken meat, levels as low as 100 CFU per 0.1 g of stool specimen or per ml of milk or food homogenate could be detected if an 8- to 12-h preculture step using combined lactose-tetrathionate broth was performed prior to the PCR.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed O. El-Gendy ◽  
Dag A. Brede ◽  
Tamer M. Essam ◽  
Magdy A. Amin ◽  
Shaban H. Ahmed ◽  
...  

AbstractNosocomial infections caused by enterococci are an ongoing global threat. Thus, finding therapeutic agents for the treatment of such infections are crucial. Some Enterococcus faecalis strains are able to produce antimicrobial peptides called bacteriocins. We analyzed 65 E. faecalis isolates from 43 food samples and 22 clinical samples in Egypt for 17 common bacteriocin-encoding genes of Enterococcus spp. These genes were absent in 11 isolates that showed antimicrobial activity putatively due to bacteriocins (three from food, including isolate OS13, and eight from clinical isolates). The food-isolated E. faecalis OS13 produced bacteriocin-like inhibitory substances (BLIS) named enterocin OS13, which comprised two peptides (enterocin OS13α OS13β) that inhibited the growth of antibiotic-resistant nosocomial E. faecalis and E. faecium isolates. The molecular weights of enterocin OS13α and OS13β were determined as 8079 Da and 7859 Da, respectively, and both were heat-labile. Enterocin OS13α was sensitive to proteinase K, while enterocin OS13β was resistant. Characterization of E. faecalis OS13 isolate revealed that it belonged to sequence type 116. It was non-hemolytic, bile salt hydrolase-negative, gelatinase-positive, and sensitive to ampicillin, penicillin, vancomycin, erythromycin, kanamycin, and gentamicin. In conclusion, BLIS as enterocin OS13α and OS13β represent antimicrobial agents with activities against antibiotic-resistant enterococcal isolates.


Author(s):  
Andrea Lauková ◽  
Anna Kandričáková ◽  
Eva Bino

This study investigated eight types of Slovak dry fermented meat products (salami and sausages) that are available on the market and were produced by three different producers in different regions of Slovakia. The total counts of enterococci in these products ranged from 2.0 up to 6.0 cfu/g (log10). Three species were identified among the 15 selected enterococcal strains; Enterococcus faecium (8 strains), Enterococcus faecalis (3) and Enterococcus hirae (4). They were hemolysis-negative (γ-hemolysis) with a biofilm-forming ability, which was evaluated as low-grade biofilm formation, susceptible to conventional antibiotics and mainly susceptible to lantibiotic bacteriocins, namely, gallidermin and nisin; they even showed a higher susceptibility to gallidermin than to nisin. They were also susceptible to enterocin–durancin, but most strains showed resistance to enterocin A/P. This study indicated that bacteriocins can play a key role in preventing and/or protecting from undesirable bacterial multiplication or contamination in the food industry and that they have great potential for further experimental applications.


2013 ◽  
Vol 33 (5) ◽  
pp. 575-580 ◽  
Author(s):  
Ana Claudia F. Borges de Campos ◽  
Nara R. Souza ◽  
Patrícia H.C. da Silva ◽  
Ângela P. Santana

O objetivo deste trabalho foi realizar o isolamento e analisar o perfil de resistência antimicrobiana de Enterococcus de carcaças de frango resfriadas e congeladas comercializadas no Distrito Federal, detectando genes de resistência antimicrobiana e identificando as espécies Enterococcus faecalis e Enterococcus faecium por reação polimerase em cadeia. Foram analisadas 100 carcaças de frangos, das quais foram isoladas 50 cepas de Enterococcus spp., sendo 42% de E. faecalis e 2% de E. faecium. O teste de susceptibilidade antimicrobiana demonstrou que todas as cepas isoladas apresentaram resistência a pelo menos um antimicrobiano, dos quais 90,47% das cepas de E. faecalis, 100% das cepas de E. Faecium e 82,14% dos Enterococcus spp. apresentaram resistência à Tetraciclina; 80,95% das cepas de E. faecalis e 35,71% das cepas de Enterococcus spp. foram resistentes à Eritromicina; 39,28% dos Enterococcus spp. e 23,80% dos E. faecalis à Ciprofloxacina e 28,57% dos E. faecalis apresentaram resistência ao Cloranfenicol. Foram detectados os genes de resistência antimicrobiana erm(B), vanC-1, aph(3')-llla, ant(6)-la, vanB, vanA, aac(6')-le-aph(2'')-la, erm(A) e tet(M) - este último mais frequente. Estes resultados sugerem sérios problemas para a Saúde Pública, uma vez que esses microrganismos podem possuir a capacidade de transmitir genes de resistência antimicrobiana para outros microrganismos presentes na microbiota intestinal de humanos e animais, podendo inviabilizar o uso destas drogas para tratamentos clínicos.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Paul Attien ◽  
Haziz Sina ◽  
Wardi Moussaoui ◽  
Gaëlle Zimmermann-Meisse ◽  
Thomas Dadié ◽  
...  

The aim of our study was to investigate the microbial quality of meat products and on some clinical samples in Abidjan focused onStaphylococcusgenus and the toxin production profile ofStaphylococcus aureus(S. aureus) isolated. Bacteria were collected from 240 samples of three meat products sold in Abidjan and 180 samples issued from clinical infections. The strains were identified by both microbiological and MALDI-TOF-MS methods. The susceptibility to antibiotics was determined by the disc diffusion method. The production of Panton-Valentine Leukocidin, LukE/D, and epidermolysins was screened using radial gel immunodiffusion. The production of staphylococcal enterotoxins and TSST-1 was screened by a Bio-Plex Assay. We observed that 96/240 of meat samples and 32/180 of clinical samples were contaminated byStaphylococcus. Eleven species were isolated from meats and 4 from clinical samples. Forty-twoS. aureusstrains were isolated from ours samples. Variability of resistance was observed for most of the tested antibiotics but none of the strains displays a resistance to imipenem and quinolones. We observed that 89% of clinicalS. aureuswere resistant to methicillin against 58% for those issued from meat products. AllS. aureusisolates issued from meat products produce epidermolysins whereas none of the clinical strains produced these toxins. The enterotoxins were variably produced by both clinical and meat product samples.


2021 ◽  
Vol 32 (2) ◽  
pp. 303-312
Author(s):  
MD. BOKTHIER RAHMAN ◽  
MD. SAZEDUL HOQUE ◽  
SUPRAKASH CHAKMA ◽  
SHAIDA AKTER ◽  
S.M. OASIQUL AZAD ◽  
...  

The study was conducted in aims to investigate the effects of frozen storage and cooking conditionson proximate compositions and formaldehyde content (FA) in some selected fish from three different sourcesin Bangladesh. Proximate composition in fresh and final frozen samples was determined by standard AOACmethod and FA content in fresh, frozen stored, and cooked samples was determined by spectrophotometricmethod. Among the studied fishes, marine fish contained higher protein (except Rita), lipid, and ash followedby estuarine and culture fish samples. Protein, moisture and ash content decreased and lipid content increasedsignificantly (p<0.05) during frozen storage for all samples and sources. The FA was lower in cultured fishsamples compared to that of the river and marine fish samples, both at fresh and end of frozen storage. Atfresh condition, FA content in all samples ranged from 0.41 to 0.71µg/g, 0.51 to 0.89µg/g, and 0.73 to1.69µg/g which increased to 0.95 to 2.11µg/g, 1.74 to 1.95µg/g, and 3.22 to 5.20µg/g at end of the storageperiod, respectively (p<0.05). Further, FA content significantly decreased after cooking in all the fishsamples (p<0.05). However, irrespective of fish species and sources, the FA content was higher than WHOrecommended value (0.2 µg/g). The study findings revealed that longer frozen storage of fish could be apublic health concern to the consumers.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5007
Author(s):  
Małgorzata Szultka-Młyńska ◽  
Daria Janiszewska ◽  
Paweł Pomastowski ◽  
Michał Złoch ◽  
Wojciech Kupczyk ◽  
...  

The bacterial infection of post-operative wounds is a common health problem. Therefore, it is important to investigate fast and accurate methods of identifying bacteria in clinical samples. The aim of the study was to analyse the use of the MALDI-TOF MS technique to identify microorganism wounds that are difficult to heal. The most common bacteria are Escherichia coli, Staphylococcus spp., and Enterococcus spp. We also demonstrate the effect of culture conditions, such as the used growth medium (solid: Brain Heart Infusion Agar, Mueller Hilton Agar, Glucose Bromocresol Purple Agar, and Vancomycin Resistance Enterococci Agar Base and liquid: Tryptic Soy Broth and BACTEC Lytic/10 Anaerobic/F), the incubation time (4, 6, and 24h), and the method of the preparation of bacterial protein extracts (the standard method based on the Bruker guideline, the Sepsityper method) to identify factors and the quality of the obtained mass spectra. By comparing the protein profiles of bacteria from patients not treated with antibiotics to those treated with antibiotics based on the presence/absence of specific signals and using the UniProt platform, it was possible to predict the probable mechanism of the action of the antibiotic used and the mechanism of drug resistance.


Author(s):  
Yara Elahi ◽  
Ramin Mazaheri Nezhad Fard ◽  
Arash Seifi ◽  
Saeideh Mahfouzi ◽  
Ali Akbar Saboor Yaraghi

Background: Bacteriophages are viruses that infect bacteria. Bacteriophages are widely distributed in various environments. The prevalence of bacteriophages in water sources, especially wastewaters, is naturally high. These viruses affect evolution of most bacterial species. Bacteriophages are able to integrate their genomes into the chromosomes of their hosts as prophages and hence transfer resistance genes to the bacterial genomes. Enterococci are commensal bacteria that show high resistance to common antibiotics. For example, prevalence of vancomycin-resistant enterococci has increased within the last decades. Methods: Enterococcal isolates were isolated from clinical samples and morphological, phenotypical, biochemical, and molecular methods were used to identify and confirm their identity. Bacteriophages extracted from water sources were then applied to isolated Enterococcus faecium (E. faecium). In the next step, the bacterial genome was completely sequenced and the existing prophage genome in the bacterial genome was analyzed. Results: In this study, E. faecium EntfacYE was isolated from a clinical sample. The EntfacYE genome was analyzed and 88 prophage genes were identified. The prophage content included four housekeeping genes, 29 genes in the group of genes related to replication and regulation, 25 genes in the group of genes related to structure and packaging, and four genes belonging to the group of genes associated with lysis. Moreover, 26 genes were identified with unknown functions. Conclusion: In conclusion, genome analysis of prophages can lead to a better understanding of their roles in the rapid evolution of bacteria.


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