Numbers Of Coagulase-positive Staphylococci Research Articles

Microbiological Risks of Traditional Raw Cow's Milk Cheese (Koryciński Cheeses).

Traditional and regional foods have been increasing in popularity among consumers in Poland for many years. The observed trend of searching for natural and authentic taste encourages many producers to craft products from raw milk, including Koryciński cheeses. The aim of this study was to assess the microbiological hazards resulting from the presence of pathogenic bacteria in Koryciński cheeses available in retail trade. The tests were carried out using accredited methods, including the detection of the presence of Salmonella spp., the enumeration of Listeria monocytogenes, the enumeration of coagulase-positive staphylococci, and the detection of staphylococcal enterotoxins in food when the number of coagulase-positive staphylococci in the sample exceeded the limit of 105 cfu/g. The research material consisted of 45 Koryciński cheeses. The tests conducted revealed that Salmonella spp. was not detected in any of the examined cheeses. However, coagulase-positive staphylococci were present in 68.9% of the samples. In as many as 15 tested cheeses, the level of S. aureus contamination was above 105 cfu/g; therefore, these samples were tested for the presence of staphylococcal enterotoxins. The presence of staphylococcal enterotoxins was found in one Koryciński cheese. In four cheeses, the number of L. monocytogenes exceeded the level of 102 cfu/g, the limit specified in Regulation 2073/2005 on microbiological criteria for foodstuffs. The obtained research results confirm the validity of monitoring the microbiological quality of Koryciński cheeses and the need to increase awareness of ensuring proper hygienic conditions of production, including the increased risk associated with unpasteurized milk products.

Investigation of microbiological safety of dry cat foods marketed in Poland.

Pets are inhabiting more and more human homes every year. In 2020, the cat population in Europe was 110 million, including 6.8 million in Poland. Dry food is the most popular dietary model for cats because of its easy storage and efficient satisfaction of pet needs. The high processing temperature of dry food reduces the chance of microbial contamination, but this can occur later, during post-production or storage in the pet's caregiver's home or, in the case of weighed foods, in the store. The purpose of this study was to investigate the microbiological safety of dry feed sold in the original manufacturer's packaging and the same feed from the same manufacturers sold in a retail store by weight. Six discriminants, presence of Salmonella spp., number of coliforms, number of coagulase-positive staphylococci, determination of yeast and mould counts, Enterobacteriaceae count, Listeria monocytogenes and determination of total aerobic microbial count were used for the analysis. Then, cat food was then stored for 45 days according to the manufacturer's recommendations. Based on the samples tested both after opening and after storage, it was concluded that the dry cat food analyzed posed a law microbiological risk to animals and humans.

MICROBIOLOGICAL SAFETY AND PHYSICOCHEMICAL QUALITY PARAMETERS OF GOAT AND SHEEP CHEESE FROM HERZEGOVINA

Cheese is a semi-solid or solid milk product, obtained by curdling milk and separating the curds from the whey. The examination included 46 samples of cheese produced on agriculture farms and small mini-dairies in the territory of Herzegovina, with the emphasis that most of the samples originate from the southern sub-Mediterranean and Mediterranean regions of Herzegovina. The goal of the study was to determine the microbiological safety and physicochemical quality parameters of cheeses that are marketed as fresh goat cheese, semi-solid goat cheese, and sheep and goat bellows cheese. Of the total number of analyzed samples, 49.22% did not meet the requirements of the physicochemical and microbiological parameters of the quality, where 36.22% did not meet the physicochemical quality, and 13% did not meet the microbiological quality due to an increased number of β glucuronidase positive Escherichia coli. The presence of β glucuronidase positive Escherichia coli in cheese samples indicates insufficient hygiene during the technological process of cheese production itself. Pathogenic microorganisms Salmonella spp and Listeria monocytogenes were not isolated, and the number of coagulase-positive staphylococci and Staphylococcus aureus was within the permitted limits. This study indicates that it is necessary to standardize the physicochemical parameters in the production of cheese, as well as the use of exclusively autochthonous raw materials in the production of individual small producers and in mini-dairies engaged in this production, as is the case with the industrial production of these products in that area.

Detection and enterotoxin production of Staphylococcus aureus isolates in artisanal cheese made from raw milk

Abstract The aim of the study was to determine whether the physicochemical factors of the matrix and the traditional acid-set cheese-making conditions allow the growth of coagulase-positive staphylococci (CoPS) and the synthesis of enterotoxins, which should contribute to an objective risk assessment in cheese production related to CoPS. CoPS were isolated from 72% of acid-set cheeses ranging from 1.70 to 5.15 log10 CFU g−1. CoPS in a number ≥ 4 log10 CFU g−1 were determined in 5.56% of the acid-set cheese samples. Out of the total number of CoPS isolated from cheese, 37.62% of the isolates have been shown to produce enterotoxins. All isolated strains that produced enterotoxins were identified as Staphylococcus aureus based on the detection of spa gene by PCR. For cheese-derived isolates with CoPS number ≥ 4 log10 CFU g−1, it has been proven that they possess sec gene encoding staphylococcal enterotoxin C. According to our results, during the proper fermentation process of artisanal acid-set cheese, the conditions do not support the growth of a critical level of staphylococci or the production of enterotoxins.

EFFICACY AND SAFETY OF 20% AZELAIC ACID CREAM FOR PAPULO-PUSTULAR ACNE VULGARIS

Purpose of the study. To determine the safety and efficacy of 20% azelaic acid cream in the treatment of patients with papulopustular acne vulgaris.
 Materials and methods. 65 patients with acne vulgaris were examined. The control group consisted of 30 healthy individuals. Acne severity was evaluated according to G. Michaelsson et al. scale, Cook’s scale, absolute number of papules and pustules. Assessment of quality of life was performed. Facial skin microbiocenosis was assessed. All patients with acne vulgaris applied 20% azelaic acid cream during 15 ± 2 days.
 Results and discussion. The use of 20% azelaic acid cream contributed to the rapid regression of inflammatory acne. After 10 days of treatment, the number of papulopustular elements decreased in 3 times. After 10 days of therapy acne score according to G. Michaelsson et al. decreased in 1,5 times and after 15 days of treatment – in 1,9 times. After 10 days of therapy the acne score on the Cook’s scale decreased in 1,4 times. At the end of the study the acne score on the Cook’s scale was 2,4 points. There was a significant decrease in the total number of bacteria, the number of coagulase-positive staphylococci, quantity of Propionibacterium acnes on facial skin in 15 days after the start of therapy. A significant difference in the average value of the DLQI was fixed before (18,9 ± 0,31) and at the end (8,1 ± 0,54) of treatment.
 Conclusions. The high effectiveness of 20% azelaic acid cream in treatment of papulopustular acne vulgaris was proved. 20% azelaic acid cream provides a rapid regression of inflammatory forms of acne, reduction of total quantity of bacteria and Propionbacterium acnes on skin.

Safety Evaluation Of Sjenica Cheese With Regard To Coagulase-Positive Staphylococci And Antibiotic Resistance Of Lactic Acid Bacteria And Staphylococci

Abstract Sjenica cheese is an artisanal cheese stored in brine, traditionally produced from raw sheep’s milk in the southern part of Serbia - Sjenica Pester plateau. The aim of this study was to perform the safety evaluation of Sjenica cheese. As one of the safety criteria we considered the number of coagulase positive staphylococci and their enterotoxigenic potential. Antibiotic susceptibility/resistance patterns of autochthonous lactic acid bacteria and coagulase-positive staphylococci isolated from Sjenica cheese was also investigated. During the monitoring period of the cheese-making process, coagulase positive staphylococci did not reach the value of 105 cfu/g. Among coagulase positive staphylococci, 12 (46,15%) isolates showed enterotoxigenic potential and were identified as Staphylococcus intermedius (11 isolates) and Staphylococcus aureus (1 isolate). Vancomycin resistance was the most prevalent phenotypic resistance profile in coagulase positive staphylococci. Lactococci present the most dominant population among lactic acid bacteria. The most prevalent resistance phenotype in lactococci was resistance to streptomycin (83.33%), ampicillin and penicillin (70.83%); lactobacilli were characterized by resistance to vancomycin (62.5%) and tetracycline (54.17%), while resistance to streptomycin (82.46%) was the most prevalent phenotypic profile in enterococci. All coagulase positive staphylococci and lactic acid bacteria isolates that showed resistance to tetracycline on disc diffusion and E-test, were tested for the presence of ribosomal protection proteins, tet(M) and tet(K) genes. All isolates were positive for ribosomal protection proteins genes; 14 (60.87%) isolates showed tet(M) gene presence, while 2 lactobacilli isolates revealed the presence of tet(K) gene.

Detection of staphylococcal enterotoxins in foodstuffs of animal origin by ELISA method

Many foods of animal origin represent an excellent substrate for growth of Staphylococcus aureus and production of staphylococcal enterotoxins (SE) . Contamination of food of animal origin (milk and meat) with enterotoxigenic strains of coagulase positive staphylococci during the production cycle can lead to production of SE and to the occurrence of foodborne intoxication, due to consumption of the contaminated final product. The objective assessment of potential microbiological risk requires an adequate control of food of animal origin for the presence of S. aureus and staphylococcal enterotoxin. To determine the number of coagulase positive staphylococci, the EN ISO 6888-1 method was applied. For determination of the presence of staphylococcal enterotoxin the ELISA kit Transia was used. Out of 15 investigated milk products, coagulase-positive staphylococci were determined in two cheese samples and two ice cream samples. Staphylococci strains ranged from 2.07±0.06 to 6.78±0.13 log10 cfu/g/ml. Out of ten tested meat samples, three samples contained coagulase positive staphylococci, ranging from 2.60±0.11 to 3.38±0.14 log10 cfu/g. The presence of staphylococcal enterotoxin was determinited in one ice cream sample only, in the quantity of 1.56 ng/ml. This sample contained 2.39±0.03 log10 cfu/g/ml S. auerus.

The microbiological load of sheep milk from primary production to its processing

In the breeding with the average number of 220 sheep (zošľachtená valaška) with traditional hand milking in the Eastern Slovakia the microbiological load of milk during the process of primary production, transport, before and after pasteurisation as well as during dairy processing to cheese curd was observed. The results in three seasons were compared to those obtained at finishing of milking in the season before. The microbiological load of milk was observed using the bacteriological methods for determination of the presence of Staphylococcus sp. and other bacteria, and determination of the total number of staphylococci: a) in milliliter of pool milk sample; b) the transport control – smears from transport tank and determination of the total number of staphylococci in the tank milk sample; c) bacteriological examination of bulk tank milk in the dairy plant before and after pasteurisation, including examination of cheese curd. After pasteurisation no staphylococci were recorded as in milk as in cheese. Out of 112 strains of Staphylococcus aureus only four strain produced staphylococcal enterotoxins (SE), but in another 7 strains a gene for production of SE, type C was found. The measures introduced during the following season led to the fact that total numbers of coagulase-positive staphylococci in milk within the process of primary production and transport did not exceed the limit permitted by legislation, and after pasteurisation of milk and cheese curd they were not found at all.

Significance of coagulase-positive staphylococci for microbiological food safety

Staphylococcal foodborne intoxication, in which major symptoms are vomiting and diarrhoea, occurs after ingestion of thermostable staphylococcal enterotoxins produced in food by enterotoxigenic strains of coagulase-positive staphylococci. Staphylococcal enterotoxins are normally not or only slightly inactivated during food processing, storage, distribution or during the preparation of the food in the kitchen. Therefore, if enterotoxigenic staphylococci are able to grow in food to more then 105 - 106 cfu/g/ml before they are killed there is still a risk of intoxication with consumption. The legislation of the Republic of Serbia lays down criteria for coagulase- positive staphylococci in food. However, the number of coagulase-positive staphylococci may not always be a good indicator of the presence of staphylococal enterotoxins, and the number of cells may have already decreased although the product still contains enterotoxins. The microbiological criteria for coagulase-positive staphylococci and/or staphylococcal enterotoxins in food are essential and useful to protect public health.

Bacteriological Quality of Delicatessen Foods: Are Standards Needed?

Surveillance of seven types of delicatessen salads (chicken, egg, ham, macaroni, American potato, shrimp, and tuna) was conducted from March through July, 1974. Liver spread and sandwich spread were included in the sampling. Products were obtained from approximately 150 retail establishments. A separate surveillance of one central production unit and approximately 18 retail establishments, which it supplied, was also conducted. Twenty six percent to 85% of samples of products obtained from general retail outlets had aerobic plate count (APC) values of less than 100,000 per gram. Thirty six percent to 79% had coliform Most Probable Number (MPN) levels of less than 100 per gram, while 83 to 100% contained less than 10 Escherichia coli per gram. Some samples of each of the products contained low numbers of coagulase-positive staphylococci. Seventy one per cent to 96% of samples of various products, obtained from a central production unit, yielded APC values of less than 100,000 per gram. Forty five percent to 94% had coliform MPN values of less than 100 per gram. Two of six products contained low levels of coagulase-positive staphylococci in 9% and 2% of the samples examined.

The role of white cells and frequency of milking in the control of staphylococcal mastitis

It is suggested that the incidence of subclinical and clinical staphylococcal mastitis can be reduced by milking dairy cows three times a day at eight-hour intervals. This conclusion derives from experiments in which it was shown that the white cells suppressed the number of coagulase positive staphylococci in vitro in a milk culture in the early stages of incubation. In a herd milked twice a day at 9 and 15-hour intervals the bacterial count in udders was higher and clinical mastitis more common at the end of the long interval than at the end of the short interval.