scholarly journals Effects of Nisin and Lysozyme on Growth Inhibition and Biofilm Formation Capacity of Staphylococcus aureus Strains Isolated from Raw Milk and Cheese Samples

2012 ◽  
Vol 75 (9) ◽  
pp. 1627-1633 ◽  
Author(s):  
MERT SUDAGIDAN ◽  
AHMET YEMENİCİOĞLU
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Inhibition ◽  
Potential Risk ◽  
Biofilm Formation ◽  
Dairy Products ◽  
Inhibitory Concentration ◽  
Raw Milk ◽  
No Inhibition ◽  
Growth Inhibitory ◽  
Control Growth

Effects of nisin and lysozyme on growth inhibition and biofilm formation capacity of 25 Staphylococcus aureus strains isolated from raw milk (13 strains) and cheese (12 strains) were studied. Nisin was tested at concentrations between 0.5 and 25 μg/ml; the growth of all strains was inhibited at 25 μg/ml, but the resistances of strains showed a great variation at lower nisin concentrations. In contrast, lysozyme tested at concentrations up to 5.0 mg/ml showed no inhibition on the growth of strains. Nisin used at the growth inhibitory concentration prevented the biofilm formation of strains, but strains continued biofilm formation at subinhibitory nisin concentrations. Lysozyme did not affect the biofilm formation of 19 of the strains, but it caused a considerable activation in the biofilm formation capacity of six strains. Twelve of the strains contained both biofilm-related protease genes (sspA, sspB, and aur) and active proteases; eight of these strains were nisin resistant. These results suggest a potential risk of S. aureus growth and biofilm formation when lysozyme is used in the biopreservation of dairy products. Nisin can be used to control growth and biofilm formation of foodborne S. aureus, unless resistance against this biopreservative develops.

Molecular typing of staphylococcus aureus strains from Iranian raw milk and dairy products by coagulase gene polymorphisms

2015 ◽  
Vol 7 ◽  
pp. 169-177 ◽  
Author(s):  
Azar Asadollahi Dehkordi ◽  
Elahe Tajbakhsh ◽  
Forough Tajbakhsh ◽  
Faham Khamesipour ◽  
Manouchehr Momeni Shahraki ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Typing ◽  
Dairy Products ◽  
Gene Polymorphisms ◽  
Raw Milk ◽  
Milk And Dairy Products

Identification of bacterial hazards in the production of artisan fresh cheese in Cuba

2020 ◽  
Vol 87 (2) ◽  
pp. 263-265
Author(s):  
Ailin Martínez ◽  
Nivian Montes de Oca ◽  
Mabelín Armenteros ◽  
Odalys Uffo ◽  
Yamilka Riverón ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Raw Milk ◽  
Foodborne Diseases ◽  
Pathogenic Potential ◽  
Good Manufacturing Practices ◽  
Fresh Cheese ◽  
Isolated Species

AbstractArtisan fresh cheese producing farms from six provinces of Cuba were studied to identify the presence of bacterial hazards and the results are presented in this research communication. The bacterial hazards identified in milk and cheese respectively were: Listeria spp. (9.5 and 18.9%), Bacillus cereus (23.2 and 24.2%), Escherichia coli O157 (12.6 and 13.7%), Salmonella spp. (10.5 and 17.9%), and Staphylococcus aureus (29.5 and 51.6%). Listeria monocytogenes was not detected. Nine Salmonella serotypes corresponding to Salmonella enterica subsp. enterica and Salmonella enterica subsp. arizonae were isolated, whereas Salmonella Anatum was present most often. Biofilm formation by the isolated species and enterotoxin production by S. aureus strains demonstrated the pathogenic potential of the identified bacterial hazards. Results proved the presence of bacterial hazards in the raw milk and cheeses analyzed, so that good manufacturing practices must be accomplished throughout the entire production process in order to avoid the occurrence of foodborne diseases in the population.

scholarly journals Enterotoxins production, biofilm formation and antimicrobial resistance of Staphylococcus aureus strains isolated from refrigerated raw cow milk

2019 ◽  
Vol 42 ◽  
pp. e45231
Author(s):  
Camila Lampugnani ◽  
Maike Taís Maziero Montanhini ◽  
Maria Emilene Martino Campos‐Galvão ◽  
Luis Augusto Nero ◽  
Luciano dos Santos Bersot
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Raw Milk ◽  
Cow Milk ◽  
In Vitro Assays ◽  
Vitro Assay ◽  
Milk Samples ◽  
Adherence Ability

This study aimed to isolate Staphylococcus aureus in refrigerated raw cow milk, and identify the presence of enterotoxin-expression genes, enterotoxin production and adherence ability, and antimicrobial resistance potential of the isolated strains. Fifty raw milk samples obtained in different dairy farms were analyzed for S. aureus and evaluated in the isolates the presence of genes associated with the production of major staphylococcal enterotoxins and biofilm formation. In vitro assays were also performed to evaluate the production of enterotoxins and adherence ability, and the antimicrobial resistance. One half (25/50) of raw milk samples presented coagulase-positive staphylococci and 95.2% of the isolates were confirmed to be S. aureus. Among them, 42.4% were carrying genes for enterotoxins production; however, only one isolate was able to produce enterotoxins. All S. aureus isolates were carrying at least two genes associated with biofilm formation and 95.2% isolates was able to adhere upon the in vitro assay. All isolates demonstrated antimicrobial resistance potential to one or more of the tested antibiotics.

scholarly journals Effects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms

2007 ◽  
Vol 56 (4) ◽  
pp. 519-523 ◽  
Author(s):  
Antonia Nostro ◽  
Andrea Sudano Roccaro ◽  
Giuseppe Bisignano ◽  
Andreana Marino ◽  
Maria A. Cannatelli ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Oregano Essential Oil ◽  
Planktonic Growth ◽  
Subinhibitory Concentrations

The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n=6) and S. epidermidis (n=6) strains tested, the biofilm inhibitory concentration (0.125–0.500 %, v/v, for oregano, and 0.031–0.125 %, v/v, for carvacrol and thymol) and biofilm eradication concentration (0.25–1.0 %, v/v, for oregano and 0.125–0.500 %, v/v, for carvacrol and thymol) values were twofold or fourfold greater than the concentration required to inhibit planktonic growth. Subinhibitory concentrations of the oils attenuated biofilm formation of S. aureus and S. epidermidis strains on polystyrene microtitre plates.

scholarly journals Prevalence of Staphylococcus aureus, Klebsiella spp., Escherichia coli and Pseudomonas spp. in some common Bangladeshi milk and dairy products

2020 ◽  
pp. 5-9
Author(s):  
Partha Paul ◽  
Md. Zahid Al Hasan ◽  
Arup Kumar ◽  
Mohammad Hasan Chowdhury ◽  
Md. Jayed Chowdhury ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
High Temperature ◽  
Dairy Products ◽  
Raw Milk ◽  
Powdered Milk ◽  
Pseudomonas Spp ◽  
Klebsiella Spp ◽  
Milk And Dairy Products ◽  
Ultra High Temperature

The study was done to isolate Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. from raw milk, processed milk (powdered milk & ultra-high-temperature milk) and dairy products (mango milk, and ice cream). During 3 months’ time span of study, a total of ten samples were gathered where eight of the samples powdered milk (2), ultra-high-temperature milk (2), ice cream (2) & mango milk (2) were gathered from different places of Bangladesh & other 2 samples (raw milk) were collected from a cattle farm & individual households in & around Noakhali city. The samples were gathered under aseptic safety measures and were followed by plating on non-selective media (Nutrient broth) & selective media (Mannitol Salt Agar & Macconkey agar). The presumptive Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. isolates were identified by biochemical tests. Analysis of the result discovered that out of a total of 10 samples; raw milk (2), processed milk i.e. powdered milk (2), ultra-high-temperature milk (2) and dairy products i.e. mango milk (2) and ice cream (2) resulted in the isolation of 8 isolates (2.5%) of S. aureus, (12.5%) of Klebsiella spp., (2.5%) of Pseudomonas spp. & (2.5%) of Escherichia coli. Results recommended a probability of potential public health threat of Staphylococcus aureus, Klebsiella spp., Escherichia coli & Pseudomonas spp. resulting from contamination of milk and dairy products with pathogenic microorganisms is mainly due to unhygienic practices and conditions in the handling, production, and processing.

scholarly journals Determination of Minimum Inhibitory Concentration (MIC) and percentage Bacterial Growth Inhibition of essential oils against Gram Positive Bacterial pathogens

2019 ◽  
Vol 9 (3) ◽  
pp. 33-35
Author(s):  
S. Nagalakshmi ◽  
P. Saranraj ◽  
P. Sivasakthivelan
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Growth Inhibition ◽  
Essential Oils ◽  
Bacterial Growth ◽  
Inhibitory Concentration ◽  
Gram Positive ◽  
Bacterial Growth Inhibition

Essential oils and volatile constituents extracted from Aromatic plants are frequently used in folk medicine for prevention and treatment of different human diseases. The urge to develop alternative treatment strategies follows three different directions. In the present study, an attempt has been planned to determine the Minimum Inhibitory Concentration (MIC) and Percentage Growth Inhibition of Essential oils against two Gram positive bacterial pathogens, Staphylococcus aureus and Bacillus subtilis. The Essential oils selected for the present study was collected from Sidha Medicine Shop, Tirupattur, Vellore district, Tamil Nadu, India. The Broth dilution method was used for the determination of Minimum Inhibitory Concentration (MIC) of Essential oils. The Minimum Inhibitory Concentration (MIC) studies were conducted by using various concentrations of Essential oils viz., 25 µl/ml, 50 µl/ml, 75 µl/ml and 100 µ/ml. The Essential oils exhibits inhibitory activity against Gram positive bacteria in all the concentrations. Among the seven Essential oils tested, Mahualongif oil has showed maximum percentage bacterial growth inhibition when compared to other Essential oils. The inhibitory activity of Mahualongif oil was observed more in Staphylococcus aureus when compared to Bacillus subtilis. For Staphylococcus aureus, lowest inhibitory percentage was noticed in Pungam oil and for Bacillus subtilis lowest inhibitory percentage was noticed in Coconut oil. Keywords: Essential oils, Minimum inhibitory concentration (MIC), Percentage bacterial growth inhibition, Bacillus subtilis and Staphylococcus aureus.

scholarly journals Antibiogram of Biofilm Producing and Non-Producing Community Acquired-Methicillin Resistant Staphylococcus aureus Isolated from Potential Risk Population of Dharan, Nepal

2019 ◽  
Author(s):  
Jenish Shakya ◽  
Bijay Kumar Shrestha ◽  
Prince Subba ◽  
Hemanta Khanal
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Potential Risk ◽  
Biofilm Formation ◽  
Cold Chain ◽  
Multi Drug Resistance ◽  
Resistant Bacteria ◽  
Risk Population ◽  
Mannitol Salt Agar ◽  
Golden Yellow

Abstract Background Staphylococcus aureus is one of the common cause of hospital acquired infection and community acquired infections. Nowadays these organisms became resistant towards variety of drugs. MRSA is the emerging antibiotic resistant bacteria that are resistant to methicillin antibiotic and known to be the infectious pathogen causing severe infection and a cause of fatal mortality.Materials and methodology Altogether 200 nasal swabs and 200 hand swabs were obtained from participants and transported to microbiology lab in cold chain. The samples were swabbed in mannitol salt agar (MSA) containing oxacillin powder of 6mg/L and incubated at 37°C for 24 hrs. Staphylococcus aureus colonies were identified based on growth characteristics on MSA plates (golden yellow colonies), Gram stain and positive results for coagulase tube test and catalase test. The pure isolated MRSA were subjected to antibiotic susceptibility tests and biofilm formation assays.Results From our study the overall prevalence of CA-MRSA was 61.5%. Higher frequency of multi-drug resistant MRSA was isolated. The biofilm producing CA-MRSA were 51.2% which showed high drug resistance and rest (48.7%) were non-biofilm producers. There was significant association in biofilm production with multi-drug resistance (p<0.05). Ciprofloxacin was most sensitive drug against the isolates which was statistically significant (p<0.05). The resistant pattern of biofilm producers reported high ability of multi-drug resistance compared to non-biofilm producers (p<0.05). Microtitre plate method was found to be gold standard over tube and congo red agar method for screening biofilm formation. Surprisingly the emergence of VISA and VRSA strains were significantly reported from our study. The prevalence of VISA and VRSA among CA-MRSA was found to be 49.5% and 40.6% respectively among the isolates which indicates the failure of Vancomycin drug in clinical therapy.Conclusions The prevalence of CA-MRSA was found more in barbers followed by beauticians and municipal waste workers in comparison to healthy controls. This study reported the higher carriage of CA-MRSA in potential risk population along with emergence of VISA and VRSA strains. Improvement in personal hygiene and formulation of appropriate health policy helps to prevent CA-MRSA infection. This study concludes that CA-MRSA is still emerging with multi-drug resistance.

scholarly journals Chemical composition of essential oil in Mosla chinensis Maxim cv. Jiangxiangru and its inhibitory effect on Staphylococcus aureus biofilm formation

2018 ◽  
Vol 13 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Liang Peng ◽  
Yunhao Xiong ◽  
Mei Wang ◽  
Manman Han ◽  
Weilan Cai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Chemical Composition ◽  
Essential Oil ◽  
Biofilm Formation ◽  
Quantitative Method ◽  
Inhibitory Concentration ◽  
Inhibitory Effect ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Components ◽  
Major Chemical

AbstractThe essential oil of Mosla chinensis Maxim cv. Jiangxiangru is known for its antibacterial ability. This study aimed to investigate the chemical composition of Jiangxiangru essential oil and its inhibitory effect on Staphylococcus aureus biofilm formation. Gas chromatography/mass spectrometry (GC–MS) was used to determine the chemical composition of Jiangxiangru essential oil. Subsequently, the eight major chemical components were quantitatively analyzed using GC– MS, and their minimum inhibitory concentration (MIC) values against S. aureus were tested. Biofilm formation was detected by crystal violet semi-quantitative method and silver staining. Of the 59 peaks detected, 29 were identified by GC–MS. Of these peaks, thymol, carvacrol, p-cymene, γ-terpinene, thymol acetate, α-caryophyllene, 3-carene, and carvacryl acetate were present at a relatively higher concentration. The results of the quantitative test showed that thymol, carvacrol, p-cymene, and γ-terpinene were the major components of the essential oil. Among the eight reference substances, only thymol, carvacrol, and thymol acetate had lower MICs compared with the essential oil. Essential oil, carvacrol, carvacryl acetate, α-caryophyllene, and 3-carene showed the better inhibition of S. aureus biofilm formation. When one fourth of the MIC concentrations were used for these substances (0.0625 mg/mL for essential oil, 0.0305 mg/mL for carvacrol, 1.458 mg/mL for carvacryl acetate, 0.1268 mg/mL for α-caryophyllene, and 2.5975 mg/mL for 3-carene), the inhibition rates were over 80%. However, thymol, γ-terpinene, thymol acetate, and p-cymene showed a relatively poor inhibition of S. aureus biofilm formation. When 1× MIC concentrations of these substances were used, the inhibition rates were less than 50%. In conclusion, Jiangxiangru essential oil and its major components, carvacrol, carvacryl acetate, α-caryophyllene, and 3-carene, strongly inhibited biofilm formation in S. aureus.

Assessing and analysing contamination of a dairy products processing plant byStaphylococcus aureususing antibiotic resistance and PFGE

2000 ◽  
Vol 46 (12) ◽  
pp. 1108-1114 ◽  
Author(s):  
E C Tondo ◽  
MC M Guimarães ◽  
J AP Henriques ◽  
M AZ Ayub
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Antibiotic Susceptibility ◽  
Dairy Products ◽  
Dairy Product ◽  
Raw Milk ◽  
Food Handler ◽  
Processing Plant ◽  
Pfge Analysis ◽  
Antibiotic Susceptibility Test

A dairy product processing plant was studied for 2.5 years to examine contamination with Staphylococcus aureus and try to correlate the source of contamination. Cultures were submitted to an antibiotic susceptibility test (AST) and characterised by Pulsed-field Gel Electrophoresis (PFGE) analysis. Results showed that 35.2% (19/51) of food handlers were asymptomatic carriers of S. aureus, and that 90.4% (19/21) of raw milk sampled was contaminated. Staphylococcus aureus was isolated from only 10 samples among more than 3200 investigated dairy products. No S. aureus contamination was found on machinery. The AST analysis demonstrated sensitivity of tested S. aureus to oxacillin, cephalothin, vancomycin, gentamicin, and sulfamethoxazole/trimethoprim. AST analysis generated eight different phenotypic profiles, but did not allow us to identify the source of contamination in seven of ten final products. PFGE analysis proved to be a sensitive method as it generated 42 different DNA banding profiles among the 48 S. aureus investigated, demonstrating a lack of predominance of endemic strains in the plant, contrary to suggestions raised by antibiotic resistance typing. Based on PFGE genotyping, S. aureus strains isolated from four contaminated final products were similar to four S. aureus isolated from raw milk. Five final products contained S. aureus different from all other strains collected, and one showed similarity to a strain isolated from a food handler. These results suggest contamination by raw milk as the main source of contamination of the final dairy products.Key words: Staphylococcus aureus, dairy products, antibiotic susceptibility, PFGE.

scholarly journals Methicillin-Resistant Staphylococcus aureus in Raw Milk: Prevalence, SCCmec Typing, Enterotoxin Characterization, and Antimicrobial Resistance Patterns

2015 ◽  
Vol 78 (6) ◽  
pp. 1142-1146 ◽  
Author(s):  
ALESSANDRA RIVA ◽  
ELISA BORGHI ◽  
DANIELA CIRASOLA ◽  
SILVIA COLMEGNA ◽  
FRANCESCA BORGO ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Raw Milk ◽  
Antimicrobial Drugs ◽  
Methicillin Resistant ◽  
Sccmec Typing ◽  
Multiplex Pcr Assay ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Mrsa Strains

Staphylococcus aureus is a known major cause of foodborne illnesses, and raw milk and dairy products are often contaminated by enterotoxigenic and antimicrobial-resistant S. aureus strains. In the present study, 35 S. aureus strains were isolated from 383 raw milk samples collected from various dairy herds in the province of Milan (northern Italy). The isolates were characterized based on their antimicrobial susceptibility patterns and the presence of genes encoding staphylococcal enterotoxins (sea, seb, sec, sed, and see). About half (45.7%) of the strains were enterotoxigenic, and 37.1% were resistant to at least one of the antimicrobial drugs tested. Seven (20%) of 35 isolates were identified as methicillin-resistant S. aureus (MRSA), and SCCmec typing performed with a multiplex PCR assay revealed the presence of gene cassettes IV and V, typical of community-acquired MRSA, and I and II, characteristic of health care–associated MRSA. The MRSA strains were evaluated for the presence of the Panton-Valentine leukocidin gene, but this gene was not found. The results of the present study revealed the presence of toxin-producing S. aureus and MRSA strains in raw milk. MRSA and enterotoxigenic S. aureus in dairy farms are an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for monitoring and controlling the presence of S. aureus, especially MRSA, in dairy products.

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