Detection of coagulase gene in Staphylococcus aureus from several dairy farms in East Java, Indonesia, by polymerase chain reaction

Molecular Characteristics of Staphylococcus aureus Isolates form Food-Poisoning Outbreaks (2011-2022) in Sichuan, China

Staphylococcal food poisoning (SFP) is one of the most common foodborne diseases in the world. This study aimed to investigate the molecular epidemiological characteristics of Staphylococcus aureus isolated from SFP. A total of 103 S. aureus isolates were obtained during 2011-2022 in Sichuan, southwest China. All isolates were tested for the genomic characteristics and phylogenetic analysis by performing whole-genome sequencing. Multilocus sequence typing analysis showed 17 multilocus sequence types (STs), ST7 (23.30%), ST5 (22.33%), and ST6 (16.50%) being the most common. A total of 45 virulence genes were detected, 22 of which were staphylococcal enterotoxin (SE) genes. Among the identified SE genes, selX exhibited the highest prevalence (86.4%). All isolates carried at least one SE gene. The results of the antimicrobial resistance (AMR) gene detection revealed 41 AMR genes of 12 classes. β-lactam resistance genes (blal, blaR1, blaZ) and tetracycline resistance gene (tet(38)) exhibited a higher prevalence rate. Core genome single nucleotide polymorphism showed phylogenetic clustering of the isolates with the same region, year, and ST. The results indicated that the SFP isolates in southwest of China harbored multiple toxin and resistance genes, with a high prevalence of new SEs. Therefore, it is important to monitor the antimicrobial susceptibility and SE of S. aureus to reduce the potential risks to public health.

The first study on antimicrobial resistance of Staphylococcus aureus isolated from raw goat milk associated with subclinical mastitis in Siliragung Subdistrict, East Java, Indonesia

Background and Aim

Raw goat milk is a highly nutritious dairy product and a suitable medium for the growth of antimicrobial-resistant Staphylococcus aureus, the leading cause of subclinical mastitis. This study aimed to investigate the resistance status of S. aureus which isolated from goat milk associated with subclinical mastitis cases in Siliragung Subdistrict, Banyuwangi District, East Java, Indonesia.

Materials and Methods

The S. aureus isolates were recovered from 258 raw goat milk samples from seven different dairy goat farms. Preliminary screening of subclinical mastitis using the California mastitis test, then samples with score +3 and +4 were taken for further isolation and identification, followed by a biochemical test to determine the S. aureus. Moreover, the bacteria susceptibility test against several antimicrobials was done using the disk diffusion method.

Results

Based on our findings, a total of 66 (25.58%) raw goat milk samples were tested positive for S. aureus, of which 36.36% were identified as multidrug-resistant. Moreover, S. aureus were also identified as resistant to penicillin (81.82%), ampicillin (65.15%), erythromycin (50.52%), and gentamicin (36.09%).

Conclusion

The prevalence of S. aureus isolated from raw goat milk associated with subclinical mastitis in Siliragung Subdistrict, Banyuwangi District, Indonesia, was recorded at 25.58%. Moreover, 36.36% of S. aureus isolates were categorized as resistant to three or more classes of antibiotics. The biosafety and biosecurity procedures during the milking process should be strengthened in dairy goat farms to prevent the transmission of antimicrobial resistance among animals, humans, and environments.

The Characterization and Beta-Lactam Resistance of Staphylococcal Community Recovered from Raw Bovine Milk

Staphylococci is an opportunistic bacterial population that is permanent in the normal flora of milk and poses a serious threat to animal and human health with some virulence factors and antibiotic-resistance genes. This study was aimed at identifying staphylococcal species isolated from raw milk and to determine hemolysis, biofilm, coagulase activities, and beta-lactam resistance. The raw milk samples were collected from the Düzce (Türkiye) region, and the study data represent a first for this region. The characterization of the bacteria was performed with MALDI-TOF MS and 16S rRNA sequence analysis. The presence of coa, icaB, blaZ, and mecA was investigated with PCR. A nitrocefin chromogenic assay was used for beta-lactamase screening. In this context, 84 staphylococci were isolated from 10 different species, and the dominant species was determined as S. aureus (32.14%). Although 32.14% of all staphylococci were positive for beta hemolysis, the icaB gene was found in 57.14%, coa in 46.42%, mecA in 15.47%, and blaZ in 8.33%. As a result, Staphylococcus spp. strains that were isolated from raw milk in this study contained some virulence factors at a high level, but also contained a relatively low level of beta-lactam resistance genes. However, considering the animal–environment–human interaction, it is considered that the current situation must be monitored constantly in terms of resistance concerns. It must not be forgotten that the development of resistance is in constant change among bacteria.

Review of pork and pork products as a source for transmission of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic bacterium that can cause infection in animals and humans. Recently, MRSA from food-producing or farm animals has been identified as livestock-associated MRSA (LA-MRSA). The spread of LA-MRSA is particularly found in pork and pork products because LA-MRSA has been widely known to infect pigs. The most common type of LA-MRSA identified in pork and pork products is the clonal complex LA-MRSA 398 (LA-MRSA CC398). The MRSA strains on the surface of pork carcasses can be spread during the handling and processing of pork and pork products through human hands, cutting tools, and any surface that comes into direct contact with pork. Food infection is the main risk of MRSA in pork and pork products consumed by humans. Antibiotics to treat food infection cases due to MRSA infection include vancomycin and tigecycline. The spread of MRSA in pork and pork products is preventable by appropriately cooking and cooling the pork and pork products at temperatures above 60°C and below 5°C, respectively. It is also necessary to take other preventive measures, such as having a clean meat processing area and disinfecting the equipment used for processing pork and pork products. This review aimed to explain epidemiology, transmission, risk factors, diagnosis, public health consequences, treatment of food poisoning, and preventing the spread of MRSA in pork and pork products.

Prevalence and antibiotic resistance of Staphylococcus aureus and Escherichia coli isolated from raw milk in East Java, Indonesia

Background and Aim:

Raw milk can be a source of food-borne disease transmission and a medium for spreading antibiotic-resistant bacteria. Staphylococcus aureus and Escherichia coli are bacteria that have the pathogenic ability to attack host cells and are capable of harboring antibiotic-resistant genes. This study estimated the prevalence and antibiotic resistance of S. aureus and E. coli isolated from raw milk in East Java, Indonesia.

Materials and Methods:

Two hundred and fifty raw milk samples were collected from five dairy farms in East Java. S. aureus and E. coli were isolated using their respective selective media, whereas antibiotic susceptibility testing was performed using the Kirby–Bauer disk diffusion method. The methicillin-resistant S. aureus (MRSA) was confirmed using the oxacillin resistance screen agar test, and extended-spectrum beta-lactamase (ESBL)-producing E. coli was determined using the double-disk synergy test. The presence of mecA and blaTEM genes were screened by the polymerase chain reaction method.

Results:

Results indicated that the prevalence of S. aureus was 138 (55.2%) and that E. coli was 176 (70.4%). Of the 138 S. aureus isolated, 27 (19.6%) were MRSA, and among the 176 E. coli isolates identified, 3 (1.7%) were ESBL producers. The mecA gene was observed in 2 (7.4%) MRSA and all 3 (100%) ESBL-producing E. coli isolated harbored blaTEM genes.

Conclusion:

The presence of MRSA and ESBL-producing E. coli in raw milk is a serious public health threat, and public awareness should be raised about the dangers posed by these pathogenic organisms.

A review of horses as a source of spreading livestock-associated methicillin-resistant Staphylococcus aureus to human health

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) was first discovered in horses in 1989. Since then, LA-MRSA has begun to be considered an important strain of pathogenic bacteria in horses, which can cause LA-MRSA infection and colonization in humans with public health impacts. The anterior nares are the primary site of LA-MRSA colonization in horses, although LA-MRSA colonization may also occur in the gastrointestinal tract in horses. LA-MRSA-infected horses typically exhibit clinical infection or may not exhibit clinical infection. There are two potential risks associated with LA-MRSA colonization in horses: The possibility of disease development in horses infected with LA-MRSA and the possibility of LA-MRSA transfer to humans and other horses. The diagnosis of LA-MRSA in horses can be made by conducting in vitro sensitivity testing for oxacillin and cefoxitin, and then followed by a molecular test using polymerase chain reaction. LA-MRSA transmission in animal hospitals and on farms is most likely due to contact with horses infected or colonized by LA-MRSA. The history of prior antibiotic administration, history of prior LA-MRSA colonization, and length of equine hospitalization were described as risk factors in cases of infection and colonization of LA-MRSA in horses. Nebulized antibiotics may be a viable alternative to use in horses, but nebulized antibiotics are only used in horses that are persistently colonized with LA-MRSA. Controlling the spread of LA-MRSA in horses can be done by regularly washing horses, eradicating vectors in horse stalls such as rats, and maintaining the cleanliness of the stable and animal hospital environment. Meanwhile, cleaning hands, using gloves, and donning protective clothes are ways that humans can prevent the transmission of LA-MRSA when handling horses. This review will explain the definition of LA-MRSA in general, LA-MRSA in horses, the epi­demiology of LA-MRSA in horses, the diagnosis of LA-MRSA in horses, the transmission of LA-MRSA in horses, risk factors for spreading LA-MRSA in horses, public health impact, treatment of LA-MRSA infection in horses, and control of the spread of LA-MRSA in horses.

Usefulness of molecular typing methods for epidemiological and evolutionary studies of Staphylococcus aureus isolated from bovine intramammary infections

In cattle, Staphylococcus aureus is a major pathogen of increasing importance due to its association with intramammary infections (IMIs), which are a primary cause of antibiotic use on farms and thus of the rise in antibiotic resistance. Methicillin-resistant S. aureus (MRSA), which are frequently isolated from cases of bovine mastitis, represent a public health problem worldwide. Understanding the epidemiology and the evolution of these strains relies on typing methods. Such methods were phenotypic at first, but more recently, molecular methods have been increasingly utilized. Multiple-locus variable number tandem repeat analysis (MLVA), a high-throughput molecular method for determining genetic diversity and the emergence of host- or udder-adapted clones, appears to be the most useful PCR-based method. Despite the difficulties present in reproducibility, interlaboratory reliability, and hard work, it is agreed that pulsed-field gel electrophoresis (PFGE) remains the gold standard, particularly for short-term surveillance. Multilocus sequence typing (MLST) is a good typing method for long-term and global epidemiological investigations, but it is not suitable for outbreak investigations. Staphylococcal protein A (spa) typing is the most widely used method today for first-line typing in the study of molecular evolution, and outbreaks investigations. Staphylococcal cassette chromosome mec (SCCmec) typing has gained popularity for the evolutionary analysis of MRSA strains. Whole-genome sequencing (WGS) and DNA microarrays that represent relatively new DNA-based technologies, provide more information for tracking antibioresistant and virulent outbreak strains. They offer a higher discriminatory power, but are not suitable for routine use in clinical veterinary medicine at this time. Descriptions of the evolution of these methods, their advantages, and limitations are given in this review.

Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis Staphylococcus aureus Isolates from Bulgaria

Simple Summary

The aim of the study was to assess the resistance of bovine mastitis Staphylococcus aureus isolates to antimicrobials by comparison of laboratory methods and statistical analysis. For this, 546 mastitis milk samples at 14 farms from 9 districts in Bulgaria were examined. A total of 92 Staphylococcus aureus strains were isolated and identified. The results showed high resistance to sulfadimethoxine (87%), followed by resistance to penicillin (33.7%), erythromycin (13%), streptomycin (8.7%), tetracycline (6.5%) and gentamicin (1.1%). The comparison of the methods demonstrated more than 90% agreement for 9 tested antimicrobial drugs, hence proving reliability of results from monitoring of resistance. Considering the detected discrepancies for some of isolates, an integral evaluation through standard and modern molecular methods for Staphylococcus aureus is recommended. The results from this study add to the microbiology laboratory experience and strategies for mastitis prevention and control programmes.

Abstract

The aim of this study was to assess the resistance of bovine mastitis S. aureus isolates from farms in Bulgaria to different classes of chemotherapeutic drugs by comparison of some phenotypic and genotypic methods by means of Cohen’s kappa statistics. The study comprised 546 milk samples from subclinical and clinical mastitis at 14 farms from 9 districts in the country. A total of 92 Staphylococcus aureus strains were isolated from tested samples and identified by nuc PCR. The results demonstrated high levels of resistance to sulfadimethoxine (87%), followed by resistance to penicillin (33.7%), erythromycin (13%), streptomycin (8.7%), tetracycline (6.5%) and gentamicin (1.1%). The comparison of both phenotypic tests with respect to 9 antimicrobials revealed strong agreement with kappa coefficient 0.836. An almost complete agreement was evidenced between phenotypic resistance to penicillin and blaZ gene presence, to methicillin with mecA gene, to tetracycline with tet genes, but the agreement between erythromycin resistance and erm genes presence was moderate. This study was the first to demonstrate discrepancy between the behaviour to cefoxitin in the disk diffusion test and oxacillin in the MIC test for an isolate shown to carry the mecA gene in the subsequent genetic analysis. Considering the detected discrepancies for some of isolates, an integral evaluation through phenotypic and molecular methods for monitoring of antimicrobial resistance of Staphylococcus aureus is recommended.

Detection of mecA gene and methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and risk factors from farms in Probolinggo, Indonesia

Background: Staphylococcus aureus is commonly found in dairy cows and is a source of contamination in milk. S. aureus that are resistant to beta-lactam antibiotics (especially cefoxitin) are referred to as methicillin-resistant Staphylococcus aureus (MRSA).  The spread of MRSA cannot be separated from sanitation management during milking; it can originate from milk collected from the udder or from the hands of farmers during the milking process. The purpose of this study was to examine the level of MRSA contamination in dairy cow's milk and farmer's hand. Methods: A total of 109 samples of dairy cow's milk and 41 samples of farmer's hand swabs were collected at a dairy farm in Probolinggo, East Java, Indonesia. Samples were cultured and purified using mannitol salt agar (MSA). The profile of S. aureus resistance was established by disk diffusion test using a disk of beta-lactam antibiotics, namely oxacillin and cefoxitin. Results: The S. aureus isolates that were resistant to oxacillin and cefoxitin antibiotics were then tested for oxacillin resistance screening agar base (ORSAB) as a confirmation test for MRSA identity. S. aureus isolates suspected to be MRSA were then tested genotypically by polymerase chain reaction (PCR) method to detect the presence of the mecA gene. The results of the isolation and identification found 80 isolates (53.33%) of S. aureus. The results of the resistance test found that 42 isolates (15%) of S. aureus were resistant to oxacillin and 10 isolates (12.5%) were resistant to cefoxitin. The ORSAB test found as many as 20 isolates (47.62%) were positive for MRSA. In PCR testing to detect the presence of the mecA gene, three isolates (30%) were positive for the mecA gene. Conclusions: This study shows that several S. aureus isolates were MRSA and had the gene encoding mecA in dairy farms.

Detection of mecA gene and methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and risk factors from farms in Probolinggo, Indonesia

Background: Staphylococcus aureus is commonly found in dairy cows and is a source of contamination in milk. S. aureus that are resistant to beta-lactam antibiotics (especially cefoxitin) are referred to as methicillin-resistant Staphylococcus aureus (MRSA). The spread of MRSA cannot be separated from sanitation management during milking; it can originate from milk collected from the udder or from the hands of farmers during the milking process. The purpose of this study was to examine the level of MRSA contamination in dairy cow's milk and farmer's hand. Methods: A total of 109 samples of dairy cow's milk and 41 samples of farmer's hand swabs were collected at a dairy farm in Probolinggo, East Java, Indonesia. Samples were cultured and purified using mannitol salt agar (MSA). The profile of S. aureus resistance was established by disk diffusion test using a disk of beta-lactam antibiotics, namely oxacillin and cefoxitin. Results: The S. aureus isolates that were resistant to oxacillin and cefoxitin antibiotics were then tested for oxacillin resistance screening agar base (ORSAB) as a confirmation test for MRSA identity. S. aureus isolates suspected to be MRSA were then tested genotypically by polymerase chain reaction (PCR) method to detect the presence of the mecA gene. The results of the isolation and identification found 80 isolates (53.33%) of S. aureus. The results of the resistance test found that 42 isolates (15%) of S. aureus were resistant to oxacillin and 10 isolates (12.5%) were resistant to cefoxitin. The ORSAB test found as many as 20 isolates (47.62%) were positive for MRSA. In PCR testing to detect the presence of the mecA gene, three isolates (30%) were positive for the mecA gene. Conclusions: This study shows that several S. aureus isolates were MRSA and had the gene encoding mecA in dairy farms.

Detection of mecA gene and methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and risk factors from farms in Probolinggo, Indonesia

Background: Staphylococcus aureus is commonly found in dairy cows and is a source of contamination in milk. S. aureus that are resistant to beta-lactam antibiotics are referred to as methicillin-resistant Staphylococcus aureus (MRSA). The spread of MRSA cannot be separated from sanitation management during milking; it can originate from milk collected from the udder or from the hands of farmers during the milking process. The purpose of this study was to examine the level of MRSA contamination in dairy cow's milk and farmer's hand swabs. Methods: A total of 109 samples of dairy cow's milk and 41 samples of farmers' hand swabs were collected at a dairy farm in Probolinggo, East Java, Indonesia. Samples were cultured and purified using mannitol salt agar (MSA). The profile of S. aureus resistance was established by disk diffusion test using a disk of beta-lactam antibiotics, namely oxacillin and cefoxitin. Results: The S. aureus isolates that were resistant to oxacillin and cefoxitin antibiotics were then tested for oxacillin resistance screening agar base (ORSAB) as a confirmation test for MRSA identity. S. aureus isolates suspected to be MRSA were then tested genotypically by polymerase chain reaction (PCR) method to detect the presence of the mecA gene. The results of the isolation and identification found 80 isolates (53.33%) of S. aureus. The results of the resistance test found that 42 isolates (15%) of S. aureus were resistant to oxacillin and 10 isolates (12.5%) were resistant to cefoxitin. The ORSAB test found as many as 20 isolates (47.62%) were positive for MRSA. In PCR testing to detect the presence of the mecA gene, three isolates (30%) were positive for the mecA gene. Conclusions: This study shows that several S. aureus isolates were MRSA and had the gene encoding mecA in dairy farms.

Profile of antibiotic-resistant and presence of methicillin-resistant Staphylococcus aureus from nasal swab of dogs from several animal clinics in Surabaya, Indonesia

Aim: The research was to investigate the antibiotic resistance profile and to screen for methicillin-resistant Staphylococcus aureus (MRSA) from nasal mucosa swab of dogs. Materials and Methods: The samples were collected from three pet clinics, three K9 units, one veterinary teaching hospital, and one kennel in Surabaya. Of the 50 total samples, 24 confirmed S. aureus strains, which were used for antibiotic sensitivity tests using a disk diffusion method and screening of MRSA used oxacillin resistance screening for base (ORSAB). Results: This study showed that there were differences in antibiotic resistance patterns among different locations. Fourteen isolates were screened for MRSA by culture on ORSAB. Conclusion: MRSA carriage was found on nasal swab of dogs, and dogs can act as reservoir of MRSA for spreading to human health. Keywords: antibiotic-resistant, dogs, methicillin-resistant Staphylococcus aureus, Staphylococcus aureus.