جستجوی مقالات مرتبط با کلیدواژه « raw milk » در نشریات گروه « دامپزشکی »

Arcobacteria are the cause of common diseases between humans and animals and are transmitted through water and food. So far, little information has been published about the pathogenic mechanisms of Arcobacteria. These bacteria can also opportunistically infect people with weak immunity. cause severe diseases. The present study was conducted with the aim of investigating drug resistance of Arcobacter and identifying virulence and resistance genes in raw milk in Isfahan province. In this study, to detect Arcobacter, 350 samples of raw milk from 5 species of animals, including cows, sheep, goats, camels, and buffaloes, and 400 samples of milk products, including cheese, cream, butter, and traditional ice cream, were randomly selected. Samples were taken from the dairies of Isfahan city and around Isfahan and were transferred to the microbiology laboratory of Kurd University in the shortest possible time. Then, bacteria grown in Preston medium with the help of a sterile loop on CAMP medium (Merck-Germany), enriched with defibrinated sheep blood containing antibiotics such as vancomycin 2 mg/ml, polymyxin 0.005 mg/ml, tri Methoprim was 1 mg/ml, linear culture was done. Also, in order to evaluate the phenotypic antibiotic resistance, the simple disk diffusion method was used according to CLSI (2017) criteria Results showed that out of a total of 350 samples of raw milk and 400 samples of milk products examined, 18 samples were infected with at least one species of Arcobacter. These 18 cases were only isolated from raw milk and none of the milk products were infected with this bacterium. Also, out of 18 samples infected with Arcobacter species, 15 samples were infected with Arcobacter botzeleri and 3 samples were infected with Arcobacter cari aerophilus. It was concluded that the highest antibiotic resistance was also evaluated for ampicillin, amoxicillin-clavulanic acid, cephalothin, cefotaxime and tetracycline.

Campylobacter is a Gram-negative, microaerophilic bacterium that can be transmitted to humans through the consumption of raw milk, causing foodborne diseases. This study investigated the prevalence of pathogenic species in raw milk and local sheep cheese using molecular methods in Farsan city of Chaharmahal and Bakhtiari provinces in 2013. Twenty samples of raw milk and 20 samples of local sheep cheese were randomly collected from collection centers and traditional milk and dairy stores. All the samples were transferred to the laboratory as soon as possible in sterile containers under suitable cold chain conditions. DNA extraction from the samples was done using a commercial kit, and then polymerase chain reaction (PCR) was performed using appropriate primers to identify Campylobacter. Of the 20 samples of raw milk, 2 (10%) were contaminated with the bacteria, and none of the 20 samples of local cheese were infected. According to the results of the present study and the presence of the mentioned bacteria in milk, it is necessary to observe hygiene principles in the dairy industry, to process and use sufficient heat to destroy the bacteria in raw milk, and to use fast and accurate methods to identify this bacterium.

This study was conducted to investigate the contamination of raw milk with Escherichia coli and Escherichia coli O157 bacteria in Ramhormoz City, Iran. To examine the contamination levels, 50 samples of raw cow's milk were collected from various locations in Ramhormoz City, including the north, south, east, west, and suburbs, during both cold and warm seasons, with 25 samples collected in each season. The total count and MPN methods were utilized to enumerate bacteria and coliforms. Additional tests involved culturing samples on EMB and McConkey agar, as well as sorbitol-containing SMA with cefixime potassium tellurite for further analysis. The IMVIC test was employed for the differential diagnosis of E. coli. In 8 samples (16%), the total microbial load in raw milk was found to be unfavorable, although still within the standard range. The northern and southern regions exhibited the highest levels of E. coli contamination, with rates of 60% and 80% during the winter and summer seasons, respectively. A statistically significant difference was observed among various regions of Ramhormoz City regarding E. coli infection during the winter season (p<0.05). Moreover, the prevalence of E. coli O157 contamination reached 20% in the northern and southern regions during the winter season and increased to 40% in the southern region during the summer season. A statistically significant difference was also noted among different regions of Ramhormoz City concerning E. coli O157 contamination during the winter season (p<0.01). Contamination levels in raw milk tend to be higher during the hot season compared to the cold season. Therefore, it is imperative to uphold the cold chain, prevent mastitis in cows, and avoid mixing their milk with that of healthy cows. Additionally, adherence to proper principles during milk transfer, including the use of appropriate pumps and cooling tanks, as well as regular disinfection of milking equipment and implementation of Cleaning in Place (CIP) systems, is essential to mitigate the risk of raw milk contamination.

Salmonella is one of the most important bacteria which cause illnesses, may exist in raw foods. The presence of this bacterium in food also causes a decrease in the quality of productions and a decrease in the economic growth. Milk and its products are among the food that may contaminate with Salmonella both primarily and secondarily by employees, water, etc., and transmitted to human. In this study, 100 samples of raw milk and 50 samples of traditional cheese from different parts of Chaharmahal and Bakhtiari province were obtained to isolate and identify Salmonella bacteria using microbiological, and polymerase chain reaction tests. Also, the antibiotic resistance of Salmonella isolates was evaluated by the diffusion disk method. The results of microbiological tests showed that 7 samples were contaminated with salmonella. Suspicious isolates included 5 samples belonging to raw milk and 2 samples belonging to traditional cheeses. The results of PCR test revealed that 3 samples of suspected isolates of raw milk (%3) and 1 sample of suspected isolates of traditional cheese (%2) were S. typhimurium. The results of the antibiogram test on Salmonella isolates showed the highest sensitivity to Gentamicin and Ciprofloxacin, and the highest resistance to Ampicillin, Tetracycline and Trimethoprim sulfamethoxazole antibiotics. According to the results of the present study, raw milk and traditional cheeses are contaminated with Salmonella typhimurium, which are resistant to some antibiotics. Although the contamination of raw milk is removed during the heat treatment steps such as pasteurization, boiling or sterilization, traditional cheeses contaminated with this bacterium are considered a potential risk for the health of consumers. Therefore, the examination of traditional dairy products, especially cheese, in terms of preventing the occurrence of diseases in humans seems to be more necessary.

Salmonella bacteria is one of the most common food-borne pathogens that causedisease in humans and animals worldwide. Salmonella species, especially S. typhimurium and S.enteritidis, are among the most common causes of food-borneinfections worldwide. This study aimsto investigate the prevalence of S. typhimurium in raw milk and local sheep cheese by using the PCR method in the Farsan city of Chaharmahal and Bakhtiari provinces. For this purpose, from September to March 2011, 20 samples of raw milk and local sheep cheese was collected from livestock farms. S. typhimurium were confirmed by the PCR method and using species-specific ST11 and ST15 primers. Out of 20 Salmonella isolates, three were confirmed as S. Typhimurium by PCR. The results of the research showed that 15% of the samples of raw milk and local sheep cheese were contaminated with S. typhimurium, and this issue makes it more necessary to observe health standards during milking and transportation and avoid the consumption of raw milk, especially in the production of products such as cheese or ice cream...

Despite the high importance of Helicobacter pylori, the main source of the bacterium and the habits of its transmission to human populations have not been determined yet. The present study was performed to evaluate the prevalence and genotyping of Helicobacter pylori strains isolated from raw milk samples. A total of 180 raw bovine, ovine and caprine milk samples were randomly collected from Fars province. The presence of Helicobacter pylori in raw milk samples were was studied using the microbial culture. Genomic DNA was extracted from Helicobacter pylori isolates and the frequency of VacA, CagA, IceA and OipA genotypes was evaluated using polymerase chain reaction. In total, 53 out of 180 (29.44%) raw milk samples were contaminated with Helicobacter pylori. The prevalence of contamination in raw milk samples of bovine, ovine and caprine was 20, 38.33 and 30%, respectively. VacA s1a (69.71%), m1a (67.92%), s2 (62.26%) and m2 (58.49%) and cagA (50.94%) were the most abundant detected genotypes. The rarest detected genotypes were VacA s1c (7.54%), s1b (16.98%), m1b (18.86%) and iceA2 (7.54%), respectively. S1am1a (39.62%), s2m1a (32.07%), s1am2 (28.30%) and s2m2 (26.41%) were the most commonly detected combined genotypes. Raw milk, especially raw sheep milk, was considered as a carrier for transmission of virulent strains of Helicobacter pylori. The similarity in the genotyping pattern of the isolates probably indicates the similarity in the source of infection of the samples with Helicobacter pylori.

Listeria is one of the most important bacteria that contaminates milk and milk products. The main species that causes listeriosis in humans and animals and is transmitted through contaminated food is Listeria monocytogenes. For this purpose, in order to identify Listeria monocytogenes in raw milk and traditional butter, in the spring of 1400, 40 samples of raw milk (20) and traditional butter (20) were collected from traditional dairy stores in Amol city. The samples were immediately transferred to a food microbiology laboratory in cold condition. The samples were first cultured in peptone water enrichment medium and then the enriched samples were transferred to Palkam Listeria selective agar medium with selective Listeria monocytogenes supplementation. Then antimicrobial susceptibility of Listeria monocytogenes isolates was determined by disk diffusion method using the antibiotics ampicillin, gentamicin, erythromycin, chloramphenicol, tetracycline, and ciprofloxacin. From the total samples, the prevalence of Listeria species in raw milk and butter was 35% and 10%, respectively. The results of antibiotic susceptibility and resistance test of raw milk samples showed that they were resistant to ampicillin 85.7% and tetracycline 71.4% and among butter samples only erythromycin was 100% resistant and ampicillin 100% semi-resistant. The mean of the obtained results in the antibiogram test were analyzed with 95% confidence and one-way analysis of variance. The results of the present study indicate the potential risk of infection due to consumption of raw milk and traditional butter to Listeria monocytogenes and raw milk had higher risk than butter.

Due to the consumption of milk in the daily diet of humans as one of the main food groups, the health of this product is of particular importance. In this study, FTNIR and FTMID were used to evaluate the amount of tetracycline in raw milk and compared with the reference HPLC method. Forty milk samples were prepared with different concentrations of tetracycline 0, 50, 100 and 150 ppb. Also, by comparing the control sample with the samples containing tetracycline, the most changes in the near-infrared spectrum occur in the wavelength range of 5200 to 5000 and 7000 to 6800 and the changes of the middle infrared spectrum occur in the wavelength range of 700 to 600, 1700 to 1500 and 3400 to 3200 cm-1. Using these predictions, the amount of tetracycline was predicted by NIR and MIR methods with correlation coefficients of 0.99 and 0.90 and RMSEP error rates of 18.60 and 20.06, respectively. Although the correlation coefficient of both methods is high, but the error rate of the prediction method is high for both methods, especially the MIR method. But the results of the NIR spectrum are closer to the reference method (HPLC) and can replace this method. Due to the lower error rate of NIR and the advantages of this identification method compared to High Performance Liquid Chromatography, this method can be introduced as a suitable alternative to destructive methods of measuring tetracycline in milk.

Dairy products start from the farm, and for a high-quality dairy product, we need to raise quality standards. Manufacturers need to use methods that reduce mastitis and bacterial contamination of the tank milk. Using strategies to minimize raw milk contamination and control mastitis is also critical. Factors such as nutritional value, taste, health, demand, and freedom of choice are the reasons for the interest in consuming raw milk. Milk and its products are essential components of a healthy diet, but studies have shown that raw milk and unpasteurized milk can be contaminated with pathogens. At the point of sale, strategies have been put in place to reduce the risks of raw milk and its products, including reviewing microbial standards, labeling, and improving milk hygiene. Pre-harvest and post-harvest control measures are also critical for controlling raw milk pathogens. Another critical issue that producers and consumers should pay attention to is FDA membership. Proponents of raw milk are aware of the benefits, but they do not have enough information to support their claims, and given the information available, the disadvantages outweigh the benefits. The authors of many articles that have mentioned the benefits of consuming raw milk do not recommend its consumption due to the risks of contamination by the pathogen. Further scientific studies are needed to evaluate the quality of raw milk, determine the benefits of consuming it, and determine the beneficial factors in milk. Until these studies are performed, a sure way to prevent raw milk-related diseases is not to consume it.

Goat and sheep milk has received much attention due to the amount of salts, breeding and increase compared to cow's milk, and based on this, it is important to evaluate their quality in terms of chemical consumption. The purpose of this study was to investigate the consumption of raw milk in goats and sheep to cadmium by atomic absorption spectrometer method in Chaharmahal and Bakhtiari province.

In this study, 74 samples of raw goat and sheep milk from Lordegan, Saman, Kiar, Kohrang and Ardel cities were randomly collected and transported to the specialized food hygiene laboratory of Shahrekord Azad University for testing. This test was performed according to the AOAC standard. This cadmium was measured based on the furnace atomic absorption spectrometer (GFAAS) method.

The raw amount of cadmium in sheep milk sample was 3.31±1.53 and in goat milk was 2.33±1.23 ng/g. This range is within the normal range. The results of the study showed that raw cadmium in all sheep and goat milk samples was lower than the allowed amount reported by Codex (500 ng/g).

According to the results obtained from the present study, cadmium in sheep and goat milk samples is low and there is a risk of consuming consumables with the sample, but the consumables of sheep and goat milk obtained from industrial areas such as Lordegan are high compared to other areas. So, it is better to avoid in these areas and near busy highways and the aforementioned factories, including petrochemicals.

Toxoplasmosis is one of the most dangerous common protozoan diseases between humans and animals that infect humans in various ways. Contact with the infected animal, consuming contaminated food, and transmitting from mother to fetus is the most important means of transmission. Based on the recorded data, this study is the first report of Toxoplasma gondii in buffalo and camel milk in some parts of Iran. For this purpose, 440 raw milk samples of 5 species of animals were collected from Isfahan, Chaharmahal & Bakhtiari, Khuzestan, and Fars provinces during four seasons and studied for the presence of Toxoplasma gondii by nested-PCR. The results showed that 26 (5.9%) of the samples were infected with Toxoplasma gondii. The highest infection was observed in sheep milk (8%) and the lowest in buffalo milk (4.28%). The seasonal prevalence of infection was in winter (11.43%), autumn (6.8%), and spring (5.03%), while none of the samples obtained in summer the parasite was not infected. Contamination of raw milk and traditional dairy products with Toxoplasma gondii can either occur directly from infected animals or as a result of non-compliance with the principles of hygiene during the process of milking, transportation, storage, and cross-contamination. Therefore, proper pre-consumption of milk is recommended.

Staphylococcus aureus is the causing agent of endocarditis, sepsis and Staphylococcal food poisoning. The purpose of this study was to assess erythromycin sensitivity in 50 Vancomycin Resistant S. aureus (VRSA) and Vancomycin Sensitive S. aureus (VSSA) isolates from bovine raw milk and also to determine the distribution of erythromycin resistance genes among the isolates. Broth microdilution method was used to determine vancomycin resistance and minimum inhibitory concentration of erythromycin. The presence of the ermA, ermB, ermC and msrA genes encoding erythromycin resistance was examined by PCR. 84% of the isolates were susceptible while 16% were resistant to vancomycin. A single isolate of S. aureus was sensitive to erythromycin which did not possess any of the erythromycin resistance genes. 90% of the isolates were resistant to erythromycin, of which, no resistance gene were found in 24.4% and 51.1% were ermB positive. ErmA was not found in any of the isolates. Simultaneous presence of resistance genes was detected in eight isolates. There was not any significant relationship between erythromycin resistance genes and MICE. 37.5% of VRSA isolates contained none of the erythromycin resistance genes while 25% contained two resistance genes. Mean MICE of VRSA was higher than VSSA isolates. All the VRSA isolates were also erythromycin resistant. There was no significant relationship between erythromycin resistance genes and vancomycin sensitivity.

Neospora caninum is an intracellular protozoan parasite with global dissemination. This protozoa has been the main cause of abortion in dairy cows. The present research was done to study the seasonal and geographical prevalence of Neospora caninum in ruminants milk by molecular method. Four-hundred and forty raw milk samples were collected from Isfahan, Chaharmahal Va Bakhtiari, Khuzestan and Fars provinces through 4 seasons of the year and transferred to the laboratory. Extracted DNA samples by kit were analyzed in order to detect the Neospora caninum NC5 gene using the nested-PCR assay. From a total of 440 studied milk samples, 54 samples (12.27%) were infected with Neospora caninum. Cow milk had the highest (26%) and sheep milk had the lowest (4%) prevalence of Neospora caninum. Milk samples collected in winter had the highest (22.85%) and samples collected in the summer had the lowest (8.57%) prevalence of Neospora caninum. Milk samples collected from Chaharmahal Va Bakhtiari province had the highest (14.94%) and samples collected from Isfahan had the lowest (6.38%) prevalence of Neospora caninum. Regarding the relative prevalence of this parasite in raw milk, adoption of monitoring plans are required more than before. Additionally, considering the possibility of consumption of traditional dairy products and transmission of infection to human, complete boiling of milk is recommended before consumption.

Klebsiella pneumoniae is a gram-negative intestinal bacterium that causes nosocomial infections. The aim of this study was to evaluate the genotype of calcitonin-resistant genes (mcr-pmr) in Klebsiella pneumoniae isolated from raw milk by Multiplex-PCR. Samples were collected from 220 raw milk storage tanks in Tehran milk storage centers in 1977. Klebsiella pneumoniae strains were identified using standard biochemical and microbiological tests. DNA extraction was performed according to the National Center for Genetic and Biological Resources of Iran (MBK0041) kit. After PCR test in thermocycler apparatus to determine the presence of mcr and pmr genes, the samples were transferred onto 1% agarose gel and stained with ethidium bromide and then analyzed in dock gel apparatus. In this study, 60 genotypes of mcr and pmr genotypes were studied in 60 isolates of K. pneumoniae. Meanwhile, the Mcr gene was reported at a frequency of 11, (18.3%) and the Pmr gene was reported at a frequency of 7 (11.6). The trace of the two genes was investigated by Multiplex-PCR method. This seems to be the first study of two Mcr, Pmr genes, in Iran of milk samples isolated from milk storage tanks in industrial farms from Klebsiella pneumoniae and two of these genes were identified as the main marker.

Mycotoxin contamination of foodstuff and its transmission to consumers are extremely important from the public health point of view. Aflatoxin M1 (AFM1) is a hepatocarcinogenic toxin found in the milk of animals that have consumed feeds contaminated with aflatoxin B1. The aim of this study was to determine the level of AFM1 in raw milk at traditional dairy retails of the east of Mazandaran province. A total of 80 cow raw milk samples was randomly collected from retails of 10 cities of Mazandaran during March 2015. The level of AFM1 was measured by ELISA assay using commercial kits and a microplate reader. All raw milk samples contained measurable amounts of AFM1. The results showed that 6.25% of the total samples had higher concentrations permitted by the Institute of Standards and Industrial Research of Iran; moreover, 17.5% of the samples were contaminated with higher concentrations of AFM1 than the maximum allowed limit set by the European Commission. Results revealed any significant relationship in the AFM1 concentrations between the sampling cities. According to the outcomes, it can be concluded that adequate control measures at the farm level may have resulted in reduced concentrations of AFM1 in raw milk of Mazandaran province; however, frequent monitoring is crucial.

Evaluation of the microbial quality of raw milk is very important due to the increasing consumption of milk and the possibility of its converting into dairy products. The study of microbial load of raw milk and the evaluation of acute phase proteins can provide accurate information on the hygienic conditions and quality of raw milk. The present study was done to evaluate the microbial load and amyloid A measurement in bulk milk samples of animal farms of Tehran province. At first, 90 raw milk samples were collected and transferred to the laboratory. Somatic cell count of milk samples was done by electronic fluorescence. Then, total microbial, coliform, Escherichia coli, Staphylococcus aureus and mold and yeast counts were done. Amyloid A concentration in raw milk samples was determined using ELISA method. Mean count of total microbes, coliform, Escherichia coli, Staphylococcus aureus and mold and yeast were 15×105, 12×104, 29×103, 14×103 and 18×105 CFU/ml, respectively. Total microbial count in 72.23% of tested samples were higher than limit standard. Mean of somatic cell count was 3×105 cells in milliliter milk which were higher than limit standard in 61.11% of milk samples. Mean and standard deviation of amyloid A in milk samples was 551.83 ±47.96 ng/ml milk. The results of the present study show the relative quality of milk samples of animal farms of Tehran province. High number of somatic cells and also the concentration of amyloid A in raw milk samples indicate the possibility of occurrence of subclinical mastitis in the target cows.

Staphylococcus aureus is one of the most important virulence factors in milk and dairy products that may cause of several disease in human. Several virulence factors are involved in its ability to cause disease that one of the most important of them is the ability of the bacterium to produce biofilm. These bacteria are capable of producing polysaccharides and proteinaceous substances attached to the surfaces that leads to biofilm formation. In this study to assess the presence of S.aureus and distribution of genes encoding biofilm formation in the raw milk from Tehran city, a total of 99 raw milk samples was obtained from 4 big milk plants in the sterile conditions and assessed by conventional microbiological culturing methods and confirmed by PCR assayed. For this, nuc gene was used as the specific target sequence to detect S.aureus to identify the presence of fnbA, clfB, icaA, icaD genes which encode biofilm formation, the specific primers of every gene were exploited. Based on results of microbiological culturing and after confirming them with molecular ways, 4 isolates were detected as s.aureus (4.04%). The genes encoding biofilm formation, fnbA, cltB, & icaD were identified in all 4 isolates (100 %) and only one isolate (25%) contained icaD gene. Because the frequency of biofilm encoding genes separated from raw milk samples of Tehran city is considerable implementing hygienic principles is essential to control and preventing biofilm formation.