Contamination Of Milk Research Articles

Bisphenol A (BPA) Contamination in Whole Milk Marketed in Different Packages

Bisphenol A (BPA) Contamination in Whole Milk Marketed in Different Packages

ОЦЕНКА ИНФЕКЦИОННЫХ РИСКОВ МОЛОКА, РЕАЛИЗУЕМОГО В НЕ ПРЕДУСМОТРЕННЫХ ДЛЯ ТОРГОВЛИ МЕСТАХ

Milk is a good source of protein, calcium, vitamins, magnesium, casein. Its advantages are the pleasant taste, dietary features and the ability to quench thirst. However, in hygienic terms, it is not without drawbacks. In particular, milk is a beneficial environment for the development of various microorganisms, including pathogens, as a result of which it can easily become a carrier of infectious diseases. Therefore, the task was set to investigate the risks associated with the transmission of a number of dangerous zoonotic infectious diseases, in particular brucellosis and tuberculosis. To this end, organoleptic and laboratory studies were carried out on 20 samples of unpasteurized milk purchased from private individuals in different administrative districts of the city of Yerevan. Through organoleptic method the color, smell, taste, texture of milk was determined. Under laboratory conditions, pH, purity, density, total acidity, bacterial contamination of milk and the presence of brucellosis antibodies and causative agents of tuberculosis were detected. Milk samples were also examined for starch and soda content (milk adulteration).

The use of a homeopathic preparation in the treatment of subclinical form of mastitis in cows.

Mastitis is a disease of productive cows, widespread throughout the world, and characterized by significant economic damage to the dairy industry. The subclinical form of this disease is aggravated by additional difficulties with its diagnosis and the lack of clear treatment protocols. Therefore, the study of the effectiveness of diagnostic studies and the search for new methods of treatment of latent forms of mastitis is an important direction in scientific research in countries with developed dairy cattle breeding. Studies conducted on the number of dairy cows of the production cooperative "Izhevsky" of the Akmola region of the Republic of Kazakhstan showed that when using rapid tests Kenotest, Somatest, Mastidine test, and Wideside test, the same results were obtained when the disease was detected in cows. The effectiveness of the tests was at the level of 60%-62% when using the settling sample as a control. Medical procedures were carried out using the Aquaton-2 microwave radiation apparatus and a homeopathic preparation. When using physiotherapy with microwave radiation, a decrease in the level of microbial contamination of milk from the treated part of the udder by 1.5-5 times was observed. Biologically active substances of plant origin in the homeopathic preparation, due to the immunostimulating effect, made it possible to increase the level of γ-globulins in the blood serum of sick animals during the application. The complex use of both methods in the treatment of animals with a subclinical form of mastitis made it possible to reduce the level of somatic cells in the milk of the affected udder lobe to a level that cannot be determined using Kenotest in 4-6 days, which is 2-4 days faster than using these methods separately.

ПОКАЗАТЕЛИ НЕСПЕЦИФИЧЕСКОЙ РЕЗИСТЕНТНОСТИ МОЛОЧНОЙ ЖЕЛЕЗЫ КЛИНИЧЕСКИ ЗДОРОВЫХ И БОЛЬНЫХ МАСТИТОМ КОРОВ

The main role in the development of inflammatory process in the mammary gland, regardless of the action of technological factors, is played by changes in the interaction of systems of nonspecific resistance of this organ and pathogenic microflora of the environment. The article shows the results of study on the indicators of nonspecific resistance of the mammary gland of lactating cows with subclinical and clinically pronounced catarrhal mastitis. In the course of research, it has been found that even at the initial stage of subclinical mastitis in cows, a strong inflammatory reaction occurs in the mammary gland. This is evidenced by a significant increase in the number of somatic cells in its secretion by 20.2 times, in comparison with healthy animals, an increase in the number of neutrophils, with a decrease in monocytes and lymphocytes against the background of activation of the mammary gland protective function, which has been manifested by an increase in the content of lysozyme – by 36.2%, total immunoglobulins – by 82.7% times. The set up of catarrhal mastitis in cows was characterized by an increase in the inflammatory process in the udder against the background of an increase in antigenic load and suppression of the general nonspecific resistance of the mammary gland, which was manifested by a higher content of somatic cells in the udder secretion of 26.3, in comparison with healthy animals, an increase in the concentration of neutrophils by 2.5 times, with a decrease in monocytes and lymphocytes, as well as a decrease in the content of lysozyme in the secretion of the mammary gland by 19.8%, total immunoglobulins – by 50.0%, an increase in circulating immune complexes – by 2.3 times. At the same time, in cows with mastitis, microbial contamination of milk in case of subclinical and catarrhal mastitis increases by 12.7 and 43.7 times, respectively, in comparison with healthy animals.

Occurrence of Klebsiella pneumoniae and Salmonella spp. in beef and cow milk from central Kerala

Klebsiella pneumoniae is a clinically important opportunistic pathogen and Salmonella spp. is a major food-borne pathogen causing gastroenteritis worldwide. The present study was conducted to determine the occurrence of K. pneumoniae and Salmonella spp. in beef and cow milk collected from central Kerala. The study was conducted in a span of 10 months from, January 2022 to October 2022. A total of 400 samples, comprising of 200 raw cow milk samples and 200 beef samples, were collected from different milk societies and retail shops of Thrissur and Palakkad districts. The K. pneumoniae and Salmonella spp. were isolated by conventional culture techniques on MacConkey agar and Xylose lysine deoxycholate agar, respectively. When conventional culture technique was used, 57.50 per cent and 10.25 per cent samples were positive for K. pneumoniae and Salmonella spp., respectively. The molecular confirmation of K. pneumoniae was carried out by PCR targeting genus specific gyrA followed by species specific rpoB gene. Salmonella spp. was confirmed on PCR by amplifying species specific invA gene and spvC gene was targeted to evaluate the virulent nature of the isolates. Out of the 400 milk and beef samples analysed 50.75 per cent were positive for K. pneumoniae and 10.25 per cent were positive for Salmonella spp. Implementation of standard hygiene practices during production, distribution chain are required to avoid the contamination of milk and beef samples indented for human consumption.

TECHNOLOGICAL AND CLIMATE FACTORS AFFECTING MILK QUALITY OF DAIRY CATTLE

One of the most vulnerable spheres of human activity to environmental threats is agricultural production, which, on the one hand, is a source of significant emissions of greenhouse gases which is one of the causes of global warming, and, on the other hand, is the most dependent on its consequences. Ukraine has high positions in the world in many sectors of agricultural production. However, environmental threats are able to cause the transformation of the majority of the climatic and agricultural zones of Ukraine and make adjustments to the development of the agricultural sector of production. The consequences of climate change significantly affect agriculture, which is largely dependent on weather and climate conditions, and, accordingly, the country’s food security. The overview of the latest research on the establishment of the main technological and climatic factors affecting the quality of milk was carried out. It has been established that most researchers emphasize such natural factors as breed, seasonal changes of the year, temperature and humidity, age of the cow, stage of lactation and interval between lactations, state of health of the animal and technological factors such as housing conditions, milking technology, fodder and feeding rations, veterinary care. In different countries, cows react differently to heat stress, animals in countries with a hot arid climate with temperatures that exceed the upper critical index for a long time suffer the most. It has been proven that an increase in temperature above the critical temperature leads to oxidative stress of the body, a decrease in the content of dry matter, fat and protein in milk and an increase in somatic cells and microbial contamination of milk. Some researchers associate the predisposition or resistance to heat stress with a genetic component, others with a violation of the conditions of keeping and feeding animals. Thus, the development of further strategic programs to reduce the negative impact of climatic and technological conditions on the production and quality of milk should include breeding programs for creating populations of thermotolerant animals, adaptive technologies that reduce stress, feeding systems with the inclusion of innovative feed products that guarantee a reduction in greenhouse emissions, animal health and food safety.

Traditional Milking Hygiene Practices and their Effect on Raw Milk Quality of Rural Small-Scale Dairy Farmers in Kwa-Hlabisa, KwaZulu-Natal, South Africa

This study examines the impact of traditional hygienic milking practices employed by rural small-scale dairy farmers on the quality of raw milk. While advancements in technology have revolutionized hygienic milk production methods for both small- and large-scale farmers, rural small-scale milk producers, particularly in countries like Zimbabwe, continue to rely heavily on hand milking as their primary method of milk harvesting. To investigate this issue, a convergent parallel mixed research approach was utilized, involving face-to-face interviews with 53 selected rural small-scale dairy farmers using a structured questionnaire. The collected data were analyzed using descriptive, frequency, chi-square, and cross-tabulation analyses. The findings revealed that participants aged 50 and above constituted the majority (58.5%) and were more likely to report low income. Additionally, households with 8 to 11 members (38%) and those with no formal education (18.9%) were also more likely to report low income. Several parameters were identified as significantly affecting milk quality (p < 0.05), including hand washing after milking, back leg tying, washing of milking utensils, use of towels, teat dipping, milking when sick, covering of milk, mixing of fresh and old milk, and lack of milk pasteurization before consumption. The study concludes that traditional hygiene practices contribute to milk contamination by rural small-scale dairy farmers, compromising the quality of raw milk. To support these farmers, interventions such as the provision of a dairy extension officer, practical workshops, incentives, entrepreneurial skills training, and farmer-to-farmer visits are recommended.

Is it possible to change milk secretion of drugs with soy enriched diets in lactating ruminants?

Soy is the most commonly used protein supplement in beef and dairy diets. Soy, which is also used as a common protein source in animal feed, is palatable and has a good amino acid balance and high bioavailability. In vivo and in vitro interaction of flavonoids, including isoflavones such as genistein and daidzein, with several ABC transporters, including breast cancer resistance protein (BCRP/ABCG2), has been demonstrated. BCRP presence in ruminants could affect the efflux of hydrophobic toxins and drugs, including their active secretion to milk and a reduction in the withdrawal time of the drug milk residues. As a result of inhibition of efflux transporters such as BCRP, changes in drug pharmacokinetics and drug transfer into milk have been observed. In this respect, the use of forage supplemented with BCRP inhibitors may be beneficial to control drug accumulation in milk and prevent undesirable contamination of milk. It is aimed to reduce the drug withdrawal periods for dairy animals with the procedure in question. In this review, it is aimed to give information about the importance of soy-enriched diets in the nutrition of ruminants during the lactation period and the effect of transport proteins on the transfer of drugs into milk.

Rapid detection of Escherichia coli in dairy milk using static headspace-comprehensive two-dimensional gas chromatography.

A new approach is introduced for rapid and reliable bacteria detection in food. Namely, static headspace-comprehensive two-dimensional gas chromatography (HS-GC × GC) with backflushing. The introduced approach provides fast detection of Escherichia coli (E. coli) in enriched ultra-high-temperature processed (UHT) dairy milk. The presence of E. coli may be indicated by detecting microbial volatile organic compounds emanating from test solutions inoculated with E. coli. In the present investigation, HS-GC × GC analysis is preceded by conventional enrichment in nutrient broth and inoculated samples are clearly discernable from controls following as little as 15h sample enrichment. Headspace equilibration for 28min followed by an 8min GC × GC analysis of enriched test solutions reduces time-to-response by approximately one full day compared to conventional culture-based methods. The presence of ethanol, 1-propanol, and acetaldehyde may be used as a putative marker of E. coli contamination in milk and the introduced approach is able to detect single-cell initial bacterial load. Faster, reliable detection of pathogens and/or spoilage microbes in food products is desirable for the food industry. The described approach has great potential to complement the conventional workflow and be utilised for rapid microbial screening of foodstuff.

Determination of Aflatoxin M1 in Buffalo Milk and Products

This study aimed to investigate the presence of Aflatoxin M1 (AFM1) in raw buffalo milk and buffalo milk products such as cheese, yogurt, cream, and ice cream by ELISA technique. In the study, 175 samples were investigated, and it was determined that 146 (83.43%) of the samples had AFM1 concentrations below the LOD (limit of detection) value. In 29 samples (16.57%), the AFM1 concentration exceeded the LOD value, and in 7 (4%) of these, the AFM1 concentration was above the legal limits (50 ng/L). While AFM1 was not detected in raw buffalo milk samples, the presence of AFM1 in cheese, yogurt, cream, and ice cream samples was found to be 2.85%, 2.85%, 62.85%, and 14.3%, respectively. 2.85% of cheese samples and 17.1% of cream samples were found contaminated with AFM1 above the allowed legal limits (50 ng/L). As a result, it was determined that the potential for exposure to AFM1 by consuming buffalo cream was higher than the consumption of buffalo milk and other buffalo milk products. However, the detection of AFM1 above legal limits in buffalo milk products poses a serious risk to public health. Therefore, it is extremely necessary for public health to develop effective monitoring programs to control aflatoxin contamination in milk and new strategies to maintain inspections.

Human Breast Milk Contamination with Aflatoxins, Impact on Children’s Health, and Possible Control Means: A Review

Aflatoxins are natural toxicants produced mainly by species of the Aspergillus genus, which contaminate virtually all feeds and foods. Apart from their deleterious health effects on humans and animals, they can be secreted unmodified or carried over into the milk of lactating females, thereby posing health risks to suckling babies. Aflatoxin M1 (AFM1) is the major and most toxic aflatoxin type after aflatoxin B1 (AFB1). It contaminates human breast milk upon direct ingestion from dairy products or by carry-over from the parent molecule (AFB1), which is hydroxylated in the liver and possibly in the mammary glands by cytochrome oxidase enzymes and then excreted into breast milk as AFM1 during lactation via the mammary alveolar epithelial cells. This puts suckling infants and children fed on this milk at a high risk, especially that their detoxifying activities are still weak at this age essentially due to immature liver as the main organ responsible for the detoxification of xenobiotics. The occurrence of AFM1 at toxic levels in human breast milk and associated health conditions in nursing children is well documented, with developing countries being the most affected. Different studies have demonstrated that contamination of human breast milk with AFM1 represents a real public health issue, which should be promptly and properly addressed to reduce its incidence. To this end, different actions have been suggested, including a wider and proper implementation of regulatory measures, not only for breast milk but also for foods and feeds as the upstream sources for breast milk contamination with AFM1. The promotion of awareness of lactating mothers through the organization of training sessions and mass media disclosures before and after parturition is of a paramount importance for the success of any action. This is especially relevant that there are no possible control measures to ensure compliance of lactating mothers to specific regulatory measures, which can yet be appropriate for the expansion of breast milk banks in industrialized countries and emergence of breast milk sellers. This review attempted to revisit the public health issues raised by mother milk contamination with AFM1, which remains undermined despite the numerous relevant publications highlighting the needs to tackle its incidence as a protective measure for the children physical and mental health.

Arcobacter species in milk contamination: a prevalence-based systematic review and meta-analysis.

Milk is consumed raw or minimally processed and plays a role in the dissemination of pathogens of public health concerns. The present investigation is aimed at assessing the occurrence of pathogenic Arcobacter species in 2945 milk samples. Arcobacter data systematically retrieved from five repositories until 20 February 2022 according to PRISMA principles were logit transformed and fitted using a generalized linear mixed-effects model. The between-study heterogeneity was estimated as I2-value. Leave-one-out cross-validation and funnel plot with Egger's tests were used to assess the hardiness and bias in the model. The global prevalence of Arcobacter genus in the milk was 12% [95% confidence interval (CI): 7-19%; I2=87.3%, 95% CI: 83.0-90.6%] and no publication bias observed (Egger's test: P=0.112). Arcobacter genus prevalence in milk was 13% (95% CI: 5-30%), 10% (95% CI: 1-46%), and 9% (95% CI: 4-19%) in Europe, South America, and Asia, respectively. Arcobacter butzleri was the most prevalent [8% (95% CI: 4-13%)], followed by A. cryaerophilus [0.6% (95% CI: 0.2-33.2%)] and A. skirrowii [0.19% (95% CI: 0.03-1.2%)]. Also, species-specific prevalence of A. butzleri, A. cryaerophilus, and A. skirrowii varied continentally, but the test for species-specific/continental differences was not significantly different (P>0.5).

Antibiotic resistance and biofilm formation in Staphylococcus aureus isolated from dairy cows at the stage of subclinical mastitis in northern Kazakhstan.

Staphylococcus aureus is an important causative agent of subclinical bovine mastitis worldwide. The aim of this research was to study the ability of S. aureus to form biofilms. Additionally, we examined the genes involved in cell resistance and sensitivity to antibiotics. Samples were collected from December 2020 to May 2021 from Simmental and black-and-white cows. The study was carried out on a total number of 643cows, of which 278 (23 %) were in the subclinical mastitis stage. Finally, 64 S. aureus isolates were isolated and identified. The highest level of phenotypic resistance was observed to antibiotics of the tetracycline (tetracycline - 48.4 %, doxycycline - 32.8 %) and -lactam (ampicillin - 45.3 %, penicillin - 45.3 %) groups. The genes encoding antibiotic resistance were characterized with the polymerase chain reaction method: blaZ in 30isolates, mecA in 1isolate, ermC in 15isolates, aph (3) in 2isolates, tetK in 19isolates, tetM in 9isolates. The tested S. aureus isolates had the ability to form biofilms in 76.6 % ( ) of cases. Of these, 69.4 % were resistant to at least one antibiotic. The obtained results have shown that S. aureus, identified in cows with subclinical mastitis, was resistant mainly to tetracycline and -lactam antibiotics. In addition, S. aureus isolates expressed resistance genes to the above drugs and had the ability to form biofilm. This study will help to identify the extent of antibiotic resistance and monitor S. aureus contamination of raw milk.

Occurrence of Aflatoxin M1 in Three Types of Milk from Xinjiang, China, and the Risk of Exposure for Milk Consumers in Different Age-Sex Groups

Aflatoxin M1 (AFM1), a group 1 carcinogen, is a risk factor to be monitored in milk. This study aimed to investigate the occurrence of AFM1 in milk in Xinjiang, China, and to assess the risk of exposure for milk consumers in different age-sex groups. A total of 259 milk samples including pasteurized milk (93 samples), extended-shelf-life (ESL) milk (96), and raw donkey milk (70) were collected in Xinjiang from January to March in 2022. The AFM1 content of the milk samples was detected using a validated ELISA method. Of the 259 total samples analyzed for AFM1, 84 (32.4%) samples were contaminated at levels greater than the detection limit of 5 ng/L, with the maximum level of 16.5 ng/L. The positive rates of AFM1 in pasteurized milk and ESL milk were 43.0% (n = 40) and 45.8% (n = 44), respectively, and AFM1 was undetectable in donkey milk. The estimated daily intakes of AFM1 in each age group were lower than the hazard limits and were similar between male and female milk consumers. Therefore, the AFM1 contamination of milk in Xinjiang is low but still needs to be continuously monitored considering that children are susceptible to AFM1.

Contamination of Escherichia coli O157:H7 in Milk and Its Dairy Products in Depok, Cianjur, Sukabumi and Bandung

Escherichia coli O157:H7 is known as a foodborne pathogen that can infect humans as well as animals. Dairy cows are the main reservoir of E. coli O157:H7 strains. These bacteria have the potential to pollute milk through direct contact with cattle and the dairy farming environment. Bacteria can survive during the production process and dairy products such as cheese. The presence of E. coli O157:H7 in dairy products has not been widely reported in Indonesia. The purpose of this study was to examine E. coli O157:H7 in the fresh milk from livestock and dairy products obtained from supermarkets and traditional markets in Depok, Cianjur, Sukabumi, and Bandung. A conventional method for E. coli isolation and testing techniques and serotyping tests on O157 and H7 was used in the study. The results showed that 26 isolates (23.85%) of a total of 109 fresh milk samples were positive for E. coli. They were identified as E. coli O157:H7 were 17 (65.38%) of 26 E. coli isolates. In dairy products, E. coli O157:H7 was not detected. This indicates that biosafety and biosecurity in the of dairy cows need to be to prevent E. coli O157:H7 contamination in milk and their livestock environment.

Evaluation of milk productivity and milk quality of goats of different genotypes depending on the number of lactations

The results of assessing the dynamics of milk productivity of goats of different genotypes depending on the number of lactations in 305 days are presented. The level of average monthly milk yields was studied. Four groups of Saanen and Nubian breed goats of 10 animals each were formed for the experiment. Starting from the 1st month of lactation in all groups, milk yield increased continuously until the 4th month, and then went down by the end of lactation. The maximum average monthly milk yields were in the 2nd-4th months of lactation in all four groups of female goats. Average monthly milk yields were highest for goats of all genotypes and lactations in the 4th month. Saanen goats dominated over Nubian goats in the first lactation by 14.43 kg, or 15.96%, in the third by 4.23 kg, or 4.48%. The parameters of physicochemical and microbiological composition of the milk of Saanen and Nubian goats of different lactation numbers were studied. The content of the main milk nutrients: protein, fat and milk sugar, as well as minerals is higher in the Nubian goat breed in both lactations. The density and acidity of goat milk were in accordance with the GOST (All Union State standard). The freezing point of goat milk samples of both breeds and lactations ranged from 0.50-0.57 °C. The somatic cell content in the milk of goats of both genotypes ranged from 128 to 1500 thousand/cm3 and conformed to the standards. Bacterial contamination of milk of the goats of both breeds and lactations did not exceed permissible sanitary standards.

Safranine-O Incorporated in F127 Nanocarriers Reduces the Contamination of Staphylococcus aureus in Sheep’s Milk

Mastitis caused by Staphylococcus aureus uses antibiotics as conventional treatment, a practice that has led to bacterial resistance. Therefore, the photodynamic inactivation of microorganisms (PDIM), has the advantage of inactivating pathogens without leading to the selection of resistant microorganisms. The objective of the study was to evaluate the antimicrobial activity of the photosensitizer (PS) Safranine-O (Sf), incorporated in the nanocarrier Pluronic® F127 against strains of S. aureus isolated from sheep milk. The reduction of contamination in experimentally contaminated milk and Muller Hilton Broth (MHB), the formation of microbial biofilm, and its effect as post dipping in the decrease of total mesophilic aerobic and Staphylococcal counts in milk were evaluated. Three strains of S. aureus (SO1, SO3, SO4) and a coagulase-negative Staphylococcus (CNS) strain (SO2) were identified through the nuc and coa genes and all were sensitive to PDIM. The minimum inhibitory concentration (MIC) ranged from 1.18 to 18.75 mg/mL in the different isolates. The SO4 strain was resistant to Ampicillin and Trimetropim. When the microorganisms were cultivated in milk and MHB, there was a reduction in staph counts by 97.33% and 99.63%, respectively. In stainless steel coupons, photoinactivation reduced S. aureus adhesion by up to 45.92% (milk) and 99.5% (MHB) (p<0.05). The photoactivated Sf was similar to commercial lactic acid when applied as a dipping powder. These results showed that Sf mediated PDIM effectively inactivated pathogens that cause mastitis and reduced milk contamination.

Occurrence and antimicrobial susceptibility of Staphylococcus aureus in dairy farms and personnel in selected towns of West Shewa Zone, Oromia, Ethiopia.

Staphylococcus aureus is one of the foodborne disease-causing bacterial pathogens. A cross-sectional study was conducted in selected towns of the West Shewa Zone, Oromia, Ethiopia from December 2020 to April 2021. The objectives of the study were to estimate the occurrence and load of S. aureus in raw cows' milk, the antimicrobial susceptibility patterns of the S. aureus isolates, and assess the knowledge, attitude, and practice of the farmers on factors of antimicrobial resistance. A total of 311 samples from raw cows' milk (212), milkers' hands (44), and milking buckets (55) swabs were collected and tested. The disc diffusion method was used to test the antimicrobial susceptibility of the isolates. A questionnaire survey was conducted to assess the factors of milk contamination with S. aureus and antimicrobial resistance. The Chi-square test, one-way analysis of variance, and logistic regression analysis were used for data analyses. The result indicated that 16.72% (52/311) (95% CI: 12.75-21.34%) of the samples were positive for S. aureus. The occurrence of S. aureus was 22.73%, 16.51%, and 12.73% in milkers' hand swabs, cow milk, and milking bucket swabs, respectively. The mean count of S. aureus from raw cows' milk was 4.3± 1.45 log10 CFU/ml. About 88% of S aureus isolates were resistant to ampicillin while 82.9% and 70.7% of the isolates were susceptible to ciprofloxacin and cefotaxime respectively. The majority of the S. aureus isolates (61%) showed multi-drug resistance. The odds of S. aureus isolation from the milk of cows were significantly high in older cows (Adjusted Odds Ratio [AOR]: 5.54; p = 0.001), in late lactation stages (AOR: 3.6; p = 0.012), and in farms where house cleaning was done twice per week (AOR: 8.7; p = 0.001). A high percentage of farmers had insufficient knowledge, attitude, and practice (KAP) about the factors contributing to antimicrobial resistance. In conclusion, the poor milk hygienic practices, high rate of antimicrobial resistance (AMR), and inadequate KAP of farmers about factors of AMR suggest potential public health risks thus requiring training and surveillance programs.

Butyric acid-producing bacterial spore levels in conventional raw milk vary by farm

Anaerobic butyric acid-producing sporeforming bacteria (BAB) are important microbial contaminants in raw milk that may lead to premature spoilage of certain cheeses during aging. A study was conducted to determine the baseline levels of these spores in raw milk from 7 conventional Northeast United States dairy farms over a 1-yr period. The overall mean BAB concentration was 1.79 log10 most probable number per liter with spore levels differing significantly by farm. A post-hoc farm management practices survey was conducted to determine if there was an association between farm practices on BAB levels in raw milk from these farms. Survey questions included variables related to bedding, milking preparation procedures, teat and udder cleanliness scoring, holding area cleaning procedures, and udder clipping or flaming frequency. Each variable was fitted with a linear mixed-effects model, which revealed no significant association between farm-level factors and the initial BAB concentrations in raw milk; this finding was likely due to the small sample size in this study. To demonstrate the usefulness of our data beyond the initial baseline levels of BAB spores in raw milk, we used this data set to calculate minimum number of individual samples that would be needed to be collected in future studies, which was determined to be 96 to 126 samples, to evaluate the association between farm-level factors and BAB spore concentrations in raw milk. Overall, this study provides dairy industry stakeholders with baseline data on BAB spore levels in raw milk, along with a demonstration on how these data could be used in future studies to calculate sample sizes needed to assess the effect of farm management practices on BAB levels in raw milk.

Gambaran Escherichia coli resistan antibiotik asal tangan pemerah, ambing sapi, susu serta air di Peternakan Sapi Perah Kecamatan Cendana, Enrekang, Sulawesi Selatan

Objective: This study aimed to describe the resistance of E. coli to several types of antibiotics isolated from water, milker hand swabs, cow udder swabs and milk in the Enrekang dairy farm, South Sulawesi. Methods: Isolation and identification of E. coli refers to SNI 2897:2008 concerning Methods for Testing Microbial Contamination in Meat, Eggs and Milk, and their Processed Products. The test of E. coli resistance to antibiotics by disc diffusion method and interpretation of the results refers to the Clinical and Laboratory Standards Institute (CLSI). The samples were 13 milker hand swabs, 52 cow udder swabs, 52 individual milks, and 13 water used for rearing activities. Results : E. coli isolates (n=64) consisted of 7 isolates from hand swabs, 7 isolates from milking hands, 20 isolates from udder swabs, 31 isolates from milk, and 6 isolates from water. E. coli isolates were resistant to erythromycin and ampicillin as much as 78%, trimethoprim-sulfamethoxazole 34.4%, tetracycline 31%, ceftazidime 25%, chloremphenicol 22%, enrofloxacin 9.4%, and gentamicin 4.6%. The pattern of E. coli resistance to antibiotics showed that the isolates of E. coli multiple drugs were resistant to up to 7 antibiotics at once. Conclusions: E. coli isolates from milk, cows, milk and water in the Enrekang dairy farming area, South Sulawesi has developed resistance to several types of antibiotics and have the potential to spread resistance genes to other bacteria and threaten human, animal and environmental health.