Molecular characterization and antibiotic resistance of Staphylococcus spp. isolated from cheese processing plants

Staphylococcus aureus Isolated From Traditional Artisanal Raw Milk Cheese from Southern Brazil: Diversity, Virulence, and Antimicrobial Resistance Profile

Staphylococcus aureus is one of the primary pathogenic agents found in cheeses produced with raw milk. Some strains of S. aureus are enterotoxigenic, possessing the ability to produce toxins responsible for staphylococcal food poisoning when present in contaminated foods. This study aimed to genotypically characterize, assess the antimicrobial resistance profile, and examine the enterotoxigenic potential of strains of S. aureus isolated from artisanal colonial cheese. Additionally, a bacterial diversity assessment in the cheeses was conducted by sequencing the 16S rRNA gene. The metataxomic profile revealed the presence of 68 distinct species in the cheese samples. Fifty-seven isolates of S. aureus were identified, with highlighted resistance to penicillin in 33% of the isolates, followed by clindamycin (28%), erythromycin (26%), and tetracycline (23%). The evaluated strains also exhibited inducible resistance to clindamycin, with nine isolates considered multidrug-resistant (MDR). The agr type I was the most prevalent (62%) among the isolates, followed by agr type II (24%). Additionally, ten spa types were identified. Although no enterotoxins and their associated genes were detected in the samples and isolates, respectively, the Panton-Valentine leukocidin gene (lukS-lukF) was found in 39% of the isolates. The presence of MDR pathogens in the artisanal raw milk cheese production chain underscores the need for quality management to prevent the contamination and dissemination of S. aureus strains.

Non-aureus staphylococci and mammaliicocci (NASM): their role in bovine mastitis and One Health

Non-aureus staphylococci (NAS) are gaining importance in mastitis and public health, and some NAS have been reclassified as mammaliicocci (NASM). Bovine milk production has a major influence on the world economy, being an essential source of income for small, medium and large producers, and bovine mastitis caused by NASM can cause an economic impact. Mastitis generates financial losses due to reduced revenue, increased veterinary costs and expenses associated with animal slaughter. However, it is also a public health issue involving animal health and welfare, human health and the ecosystem. Furthermore, it is an increasingly common infection caused by NASM, including antimicrobial-resistant strains. Despite all these adverse effects that NASM can cause, some studies also point to its protective role against mastitis. Therefore, this review article addresses the negative and positive aspects that NASM can cause in bovine mastitis, the virulence of the disease and resistance factors that make it difficult to treat and, through the One Health approach, presents a holistic view of how mastitis caused by NASM can affect both animal and human health at one and the same time.

Detection of Staphylococcus Isolates and Their Antimicrobial Resistance Profiles and Virulence Genes from Subclinical Mastitis Cattle Milk Using MALDI-TOF MS, PCR and Sequencing in Free State Province, South Africa

Staphylococcus species are amongst the bacteria that cause bovine mastitis worldwide, whereby they produce a wide range of protein toxins, virulence factors, and antimicrobial-resistant properties which are enhancing the pathogenicity of these organisms. This study aimed to detect Staphylococcus spp. from the milk of cattle with subclinical mastitis using MALDI-TOF MS and 16S rRNA PCR as well as screening for antimicrobial resistance (AMR) and virulence genes. Our results uncovered that from 166 sampled cows, only 33.13% had subclinical mastitis after initial screening, while the quarter-level prevalence was 54%. Of the 50 cultured bacterial isolates, MALDI-TOF MS and 16S rRNA PCR assay and sequencing identified S. aureus as the dominant bacteria by 76%. Furthermore, an AMR susceptibility test showed that 86% of the isolates were resistant to penicillin, followed by ciprofloxacin (80%) and cefoxitin (52%). Antimicrobial resistance and virulence genes showed that 16% of the isolates carried the mecA gene, while 52% of the isolates carried the Lg G-binding region gene, followed by coa (42%), spa (40%), hla (38%), and hlb (38%), whereas sea and bap genes were detected in 10% and 2% of the isolates, respectively. The occurrence of virulence factors and antimicrobial resistance profiles highlights the need for appropriate strategies to control the spread of these pathogens.

Identification of the Enterotoxigenic Potential of Staphylococcus spp. from Raw Milk and Raw Milk Cheeses

This study aimed to genotypic and phenotypic analyses of the enterotoxigenic potential of Staphylococcus spp. isolated from raw milk and raw milk cheeses. The presence of genes encoding staphylococcal enterotoxins (SEs), including the classical enterotoxins (sea-see), non-classical enterotoxins (seg-seu), exfoliative toxins (eta-etd) and toxic shock syndrome toxin-1 (tst-1) were investigated. Isolates positive for classical enterotoxin genes were then tested by SET-RPLA methods for toxin expression. Out of 75 Staphylococcus spp. (19 Staphylococcus aureus and 56 CoNS) isolates from raw milk (49/65.3%) and raw milk cheese samples (26/34.7%), the presence of enterotoxin genes was confirmed in 73 (97.3%) of them. Only one isolate from cheese sample (1.3%) was able to produce enterotoxin (SED). The presence of up to eight different genes encoding enterotoxins was determined simultaneously in the staphylococcal genome. The most common toxin gene combination was sek, eta present in fourteen isolates (18.7%). The tst-1 gene was present in each of the analyzed isolates from cheese samples (26/34.7%). Non-classical enterotoxins were much more frequently identified in the genome of staphylococcal isolates than classical SEs. The current research also showed that genes tagged in S. aureus were also identified in CoNS, and the total number of different genes detected in CoNS was seven times higher than in S. aureus. The obtained results indicate that, in many cases, the presence of a gene in Staphylococcus spp. is not synonymous with the ability of enterotoxins production. The differences in the number of isolates with genes encoding SEs and enterotoxin production may be mainly due to the limit of detection of the toxin production method used. This indicates the need to use high specificity and sensitivity methods for detecting enterotoxin in future studies.

Stability and emetic activity of enterotoxin like X (SElX) with high carrier rate of food poisoning Staphylococcus aureus

In order to analyze and clarify the thermal stability of food poisoning Staphylococcus aureus (S. aureus) enterotoxin-like X (SElX) and the biological characteristics of digestive enzymes, and to evaluate the risk of S. aureus carrying selx gene in food poisoning, the selx gene carrying rates of 165 strains isolated from 95 food poisoning events from 2006 to 2019 were first statistically analyzed. Subsequently, the purified recombinant SElX protein was digested and heated, and the superantigen activity was verified with mouse spleen cells and peripheral blood mononuclear cells of kittens. At the same time, the emetic activity and toxicity of SElX were evaluated using the kitten vomiting animal model, mice toxin model and in vitro cell models. The results showed the selx gene carrying rate of 165 food poisoning S. aureus strains was 90.30 %. SElX had significant resistance to heat treatment and pepsin digestion (pH = 4.0 and pH = 4.5), and had good superantigen activity and emetic activity. However, there is no significant lethal effect on mice and no significant toxicity to cells. Importantly, we found that SElX had an inhibitory effect on acidic mucus of goblet cells in various segments of the small intestine. The present study investigated the stability of SElX, and confirmed the emetic activity of SElX by establishing a kitten vomiting model for the first time, suggesting that SElX is a high risk toxin of food poisoning, which will provide new ideas for the prevention and control of S. aureus food poisoning.

Characterization of coagulase-negative staphylococci and macrococci isolated from cheese in Germany

Cheese, especially ripened varieties, harbor a very complex and heterogeneous microbiota. In addition to the desired microorganisms (starter cultures) added during cheese production, potentially harmful bacteria may also enter the production chain. Regarding the latter, the focus of this study was on coagulase-negative staphylococci (CNS) and Macrococcus caseolyticus. Both are known to harbor a variety of genes coding for antibiotic resistance, including mecA, mecB, mecC, and mecD. Coagulase-negative staphylococci or macrococci carrying such genes or other virulence factors should not be present in cheese. Cheese samples (101 in total) were collected from retail sources. Coagulase-negative staphylococci and M. caseolyticus were isolated utilizing selective agars, and species were identified by phenotypical tests and partial sequencing of the sodA gene. The results allowed identification of 53 CNS strains and 19 M. caseolyticus strains. Among the CNS, 11 isolates of Staphylococcus saprophyticus and one Staphylococcus epidermidis isolate were obtained. Both species are potential human pathogens and may thus adversely affect the safety of these food products. Screening for antimicrobial resistance was performed by application of disc diffusion tests, a gradient strip-test, and 14 different PCR tests. Evidence for methicillin resistance (by either positive disc diffusion assay for cefoxitin or by mec PCR) was found in CNS isolates and M. caseolyticus (9 isolates each). Regarding other virulence factors, no genetic determinants for coagulase or the most common staphylococcal enterotoxins sea, seb, sec, sed, and see were detected in any of the CNS or M. caseolyticus isolates by PCR testing. In conclusion, the presence of facultatively pathogenic CNS and carriers of genes for antibiotic resistance in both groups of microorganisms, especially mec genes, and the respective food safety issues need further evaluation and surveillance.

Relevant safety aspects of raw milk for dairy foods processing

The concern with food safety in the milk chain begins with the quality of the raw milk. Due to the health hazard that this food can carry when contaminated, the focus of studies has turned to microbiological and chemical contaminants that may be present in raw milk. There is an essential concern about conventional pathogens (Shiga toxin-producing Escherichia coli, Salmonella spp., Listeria monocytogenes, Campylobacter spp., Salmonella spp., and coagulase-positive Staphylococcus spp.) and emerging pathogens (Arcobacter butzleri, Yersinia enterocolitica, Mycobacterium avium ssp. paratuberculosis, Helicobacter pylori, and Cronobacter sakazakii) found in raw milk and dairy products. In addition, a growing public health issue has been raised regarding antimicrobial-resistant pathogens and commensal strains found in milk and dairy products. The antibiotic residues in milk can also damage health, such as allergies, and cause technological problems in dairy products processing. This health issue extends to other chemical contaminants such as heavy metals, pesticides, polycyclic aromatic hydrocarbons, melamine, dioxins, polychlorinated biphenyls, plasticizers, and additives in milk and dairy products. Other chemical substances formed by microorganisms are also of high importance, such as biogenic amines and mycotoxins. Therefore, this chapter aimed to revise and discuss relevant biological and chemical risks to ensure the safety and quality of raw milk and dairy products.

Prevalence and antimicrobial resistance profiling of Staphylococcus aureus isolated from traditional cheese in Yunnan, China

The prevalence of staphylococcal infection and the emergence of multidrug resistance of Staphylococcus aureus (S. aureus) are major concerns in food safety and public health. This study aimed to investigate the prevalence of S. aureus isolated from traditional Chinese Rubing and Rushan cheese, antimicrobial resistance profiles, genomic characteristics, and predict antimicrobial resistance genes (ARGs). From 124 samples, 18 of 62 (29.03%) of Rubing and 5 of 62 (8.06%) of Rushan cheese were confirmed to be S. aureus positive by standard culture-based methods. Twenty-three coagulase-positive staphylococci isolates were grouped into 16 clusters by pulsed-field gel electrophoresis and subjected to routine susceptibility testing to 12 antibiotics. Those isolates exhibited high resistance to penicillin (100%), erythromycin, trimethoprim-sulphamethoxazole (34.78%), oxacillin, clindamycin, and cefoxitin (21.74%). Multidrug-resistant (MDR) S. aureus was found in 34.78% (8 of 23) of isolates. Further, S. aureus strain DC.RB_015 isolated from Rubing cheese, recognized as the most resistant to six antibiotics, was selected for whole-genome sequencing (WGS), continued with in silico approaches. S. aureus DC.RB_015 had a single chromosome size of 2,794,578 bp and a plasmid size of 22,961 bp. The strain harbored 18 predicted ARGs, including eight efflux pump genes (mepA, tet(K), arlR, arlS, norA, mgrA, tet(38), LmrS), one peptidoglycan biosynthesis gene (bacA), two β-lactams resistance genes (mecA, blaZ), and seven genes conferring other antimicrobial resistance (APH(3')-IIIa, aad(6), ErmB, SAT-4, mecR1, GlpT, murA). The results of this study expand the knowledge of S. aureus strain DC.RB_015, increase food safety awareness, and will be helpful in establishing therapeutic therapy.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03072-4.

Directed Recovery and Molecular Characterization of Antibiotic Resistance Plasmids from Cheese Bacteria

Resistance to antimicrobials is a growing problem of worldwide concern. Plasmids are thought to be major drivers of antibiotic resistance spread. The present work reports a simple way to recover replicative plasmids conferring antibiotic resistance from the bacteria in cheese. Purified plasmid DNA from colonies grown in the presence of tetracycline and erythromycin was introduced into plasmid-free strains of Lactococcus lactis, Lactiplantibacillus plantarum and Lacticaseibacillus casei. Following antibiotic selection, the plasmids from resistant transformants were isolated, analyzed by restriction enzyme digestion, and sequenced. Seven patterns were obtained for the tetracycline-resistant colonies, five from L. lactis, and one each from the lactobacilli strains, as well as a single digestion profile for the erythromycin-resistant transformants obtained in L. lactis. Sequence analysis respectively identified tet(S) and ermB in the tetracycline- and erythromycin-resistance plasmids from L. lactis. No dedicated resistance genes were detected in plasmids conferring tetracycline resistance to L. casei and L. plantarum. The present results highlight the usefulness of the proposed methodology for isolating functional plasmids that confer antibiotic resistance to LAB species, widen our knowledge of antibiotic resistance in the bacteria that inhabit cheese, and emphasize the leading role of plasmids in the spread of resistance genes via the food chain.

Antimicrobial resistance of Staphylococcus spp. isolated from organic and conventional Minas Frescal cheese producers in São Paulo, Brazil

The genus Staphylococcus is recognized worldwide as a cause of bacterial infections in humans and animals. Antibiotics used in dairy cattle combined with ineffective control can increase antimicrobial resistance. The objective of this study was to characterize 95 Staphylococcus strains isolated from organic and conventional Minas Frescal cheese production regarding antibiotic resistance (phenotype and genotype), presence of sanitizer-resistant genes and biofilm-formation genes, and SCCmec typing. Most strains (25.3%) showed higher resistance to penicillin, followed by oxacillin (21.1%) and clindamycin (11.6%). Among antibiotic resistance genes, the most prevalent were blaZ (25.3%), mecA (13.7%), lsaB (6.3%), msrA (4.2%), ant4 (3.2%), and tetM (2.1%); among sanitizer-resistance genes they were qacA/B (5.3%) and qacC (6.3%); and among biofilm, bap (4.2%), icaA (29.5%), icaD (41.1%). However, there was no statistically significant difference between organic and conventional dairy products, possibly due to the lack of synthetic antibiotic use on conventional farms during the sample collection period. Methicillin-resistant Staphylococcus aureus (MRSA) had their SCCmec identified as types I and IVc, and the methicillin-resistant coagulase-negative staphylococci had nontypeable SCCmec. These results suggest that there are antibiotic-resistant strains in both organic and conventional Minas Frescal cheese production in the state of São Paulo, Brazil. This supports the idea that improved quality control is needed from the milking stage up to the final product.

Effect of Lactobacillus rhamnosus on growth of Listeria monocytogenes and Staphylococcus aureus in a probiotic Minas Frescal cheese

This study aimed to evaluate the effect of Lactobacillus rhamnosus GG on growth of Staphylococcus aureus and Listeria monocytogenes, inoculated alone or in combination on surface of Minas Frescal cheeses, during storage for 21 days at 7 °C. Survival percentages of each individual bacterial species after exposure to in vitro simulated gastrointestinal conditions (SGC) were also determined. The addition of L. rhamnosus did not affect (P > 0.05) pH, moisture, fat, protein and texture profile of Minas Frescal cheeses. L. rhamnosus was able to survive in suitable counts (>6 Log CFU/g) in cheeses from the 7th day of storage, with high survival (>74.6-86.4%) after SGC. An inhibitory effect of L. rhamnosus on L. monocytogenes was observed in cheeses (decrease of 1.1-1.6 Log CFU/g) and after SGC (20% reduction in the survival). No inhibitory effect of L. rhamnosus was observed on S. aureus counts (P > 0.05), and this microorganism did not survive the exposure to SGC. In conclusion, the addition of L. rhamnosus in Minas Frescal cheese has a potential for L. monocytogenes inhibition. Further studies are necessary to elucidate the mechanisms involved in the inhibition process and determine the survival ability of the bacterial species evaluated in in vivo experiments.

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.

Methicillin-resistant Staphylococcus aureus in food and the prevalence in Brazil: a review

Foodborne diseases (FBD) occur worldwide and affect a large part of the population, being a cause of international concern among health authorities. Staphylococcus aureus can be transmitted by contaminated food, and it is one of the pathogens that most cause foodborne outbreaks in Brazil. Currently, this organism's ability in developing resistance to antibiotics is notorious; methicillin-resistant Staphylococcus aureus-MRSA-is known for its resistance to methicillin, oxacillin, and others. MRSA is one of the leading causes of infections, becoming a major threat to human health worldwide due to the numerous toxins that can produce. At first, the transmission of MRSA occurred in clinical environments; but in recent decades, its presence has been reported in the community, outside the hospital environment, including food and food-producing animals around the world. In this review, information about MRSA was gathered to verify MRSA incidence in the world but especially in Brazil in food samples, food handlers, food-producing animals, and food processing environments. The studies show that MRSA is easily found and in certain cases with high frequency, thus representing a potential risk to public health.

Prevalence and phylogenetic relationship among methicillin- and vancomycin-resistant Staphylococci isolated from hospital's dairy food, food handlers, and patients

Objective:

The aim of the present work was to investigate the mutual role that may be played by the served dairy food and food handlers in the transmission of methicillin- and vancomycin-resistant Staphylococcus aureus and coagulase-negative Staphylococci to patients who were hospitalized in Qena City, Egypt.

Materials and Methods:

A total of 210 samples including 90 dairy food samples which offered to the patients in the hospital, 60 nasal and hand swabs from food handlers working in the hospital, and 60 nasal and diarrheal swabs from patients suffering from diarrhea were investigated for the presence of coagulase-positive S. aureus and coagulase-negative Staphylococci, then isolates were screened for methicillin and vancomycin resistance phenotypically and genotypically. 16s rRNA gene sequencing was employed to construct the neighbor-joining tree.

Results:

Unlike food samples, both coagulase-positive S. aureus and coagulase-negative Staphylococci occurred in human samples. Methicillin- and vancomycin-resistant coagulase-negative Staphylococci could be detected in 41.7% & 20.8%, 68% & 31.9%, and 81.3% & 55.2% of isolates obtained from dairy food, food handlers, and patients’ samples, respectively. Whereas 81% & 64.3%, and 75.4% & 38.6% of coagulase-positive S. aureus obtained from food handlers and patients’ samples exhibited resistance to methicillin and vancomycin, respectively. Phenotypic resistance was confirmed molecularly through detection of mecA and vanA genes.

Conclusion:

A significant role can be played by food and food handlers in the transmission of methicillin- and vancomycin-resistant Staphylococci to patients, which has been proved in this study through the close phylogenetic relation between S. epidermidis isolated from food, food handlers, and patients’ diarrheal samples.

Characterization of coagulase-negative staphylococci from brining baths in Germany

Brining is an important step in cheese making, and using brine baths for this purpose is common practice in German dairies. Time of brining, brine concentration, and composition of the complex and heterogeneous microbiota, including coagulase-negative staphylococci (CNS), contribute to the ripening and taste of cheese. As well as producing staphylococcal enterotoxins, some CNS show antibiotic resistance; therefore, we isolated 52 strains of presumptive CNS from cheese brines from 13 factories in Germany. Species identification by sodA gene sequencing revealed that 50 isolates were CNS: 31 Staphylococcus saprophyticus, 4 Staphylococcus carnosus, 4 Staphylococcus equorum, 3 Staphylococcus sciuri, 2 Staphylococcus hominis, and 2 Staphylococcus warneri. One isolate each was identified as Staphylococcus epidermidis, Staphylococcus pasteurii, Staphylococcus succinus, and Staphylococcus xylosus. Further subtyping of the Staph. saprophyticus isolates to the subspecies level revealed the presence of 6 Staph. saprophyticus ssp. saprophyticus. Using pulsed-field gel electrophoresis with the identified Staph. saprophyticus strains, 12 independent clones were identified, resulting in the exclusion of 18 strains from further testing. In 19 of the remaining 32 CNS isolates, resistance to antibiotics was observed. Resistance was found against oxacillin (17), penicillin (5), and cefoxitin (1). Four isolates expressed resistance to both oxacillin and penicillin. No resistance was found to enrofloxacin, tetracycline, gentamicin, or erythromycin. Then, PCR analysis for antibiotic resistance genes was performed for 22 different genes. Only genes blaZ and bla_TEM were found in 7 isolates. These isolates were selected for challenge tests with different concentrations of lactic acid and NaCl to examine whether expression of antibiotic resistance was influenced by these stressors. An increase in the minimal inhibitory concentration from 0 to 2.0 µg/mL was seen for trimethoprim/sulfamethoxazole only in one isolate of Staph. saprophyticus at an increased lactic acid concentration. Finally, all isolates were tested for genetic determinants (entA, entB, entC, entD, and entE) of the most common staphylococcal enterotoxins; none of these genes were detected. We found no indication for unacceptable risks originating from the isolated CNS.

Phenotypic and genotypic characterization of Staphylococcus spp. isolated from mastitis milk and cheese processing: Study of adherence and biofilm formation

The aim of this study was to identify the phenotypic and genotypic profiles of Staphylococcus spp. isolated from mastitis milk and cheese processing plant.To evaluate the biofilm production of wild-type strains on contact surfaces by testing different factors through adhered cells and biofilm quantifications, finally, these biofilms were observed by Scanning Electron Microscopy (SEM). Congo red agar (CRA) plate method was used to identify slime production by strains. Screening of genes encoding adhesion factors and biofilm formation was carried out using PCR. After strains selection, adhesion and biofilm assays were designed testing different times (12, 48, 96 h), strains (n = 13), contact surfaces (stainless steel and polypropylene), and temperatures (5 °C and 25 °C); and then, bacterial count and crystal violet staining were conducted. Relative frequencies of positive on CRA and genes presence were determined, and Friedman test was applied for bacterial counts and OD values. Additionally, significant factors (P ≤ .05) were subjected to multiple comparisons using the Nemenyi test. The slime production in CRA was observed by visual inspection in 38.7% of strains. A large distribution of genes was described among strains, implying a high variability of genotypic profiles. Moreover, relative frequencies of CRA positive and gene presence were described. The developed assay showed that the strain, temperature, contact surface, were significant for both variables. The SEM corroborated the findings, showing greater biofilm formation on stainless steel at 25 °C. Thus, it is essential to highlight the importance of temperature control and material with low superficial energy to avoid biofilm formation by staphylococci.