Prevalence Of Methicillin-resistant Staphylococcus Aureus Research Articles

Resistome, Virulome, and Clonal Variation in Methicillin-Resistant Staphylococcus aureus (MRSA) in Healthy Swine Populations: A Cross-Sectional Study.

This cross-sectional study investigates the methicillin-resistant Staphylococcus aureus (MRSA): its prevalence, antimicrobial resistance, and molecular characteristics in healthy swine populations in central Portugal. A total of 213 samples were collected from pigs on twelve farms, and MRSA prevalence was assessed using selective agar plates and confirmed via molecular methods. Antimicrobial susceptibility testing and whole genome sequencing (WGS) were performed to characterize resistance profiles and genetic determinants. Among the 107 MRSA-positive samples (83.1% prevalence), fattening pigs and breeding sows exhibited notably high carriage rates. The genome of 20 isolates revealed the predominance of the ST398 clonal complex, with diverse spa types identified. Antimicrobial susceptibility testing demonstrated resistance to multiple antimicrobial agents, including penicillin, cefoxitin, and tetracycline. WGS analysis identified a diverse array of resistance genes, highlighting the genetic basis of antimicrobial resistance. Moreover, virulence gene profiling revealed the presence of genes associated with pathogenicity. These findings underscore the significant prevalence of MRSA in swine populations and emphasize the need for enhanced surveillance and control measures to mitigate zoonotic transmission risks. Implementation of prudent antimicrobial use practices and targeted intervention strategies is essential to reducing MRSA prevalence and safeguarding public health. Continued research efforts are warranted to elucidate transmission dynamics and virulence potential, ultimately ensuring food safety and public health protection.

Prevalence and Antibiogram of Methicillin Resistant Staphylococcus aureus Nasal Carriage among Apparently Healthy University Staff and Students in Kaduna, Nigeria

Methicillin Resistant Staphylococcus aureus (MRSA) has been frequently implicated in healthcare-associated infections. Hence, the objective of this paper was to investigate the prevalence and antibiogram of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among apparently healthy University staff and students in Kaduna, Nigeria. A total of 250 nasal swab samples were collected alongside demographic data. Gram staining and biochemical tests were carried out to identify the Staphylococcus aureus. Methicillin-resistance was determined phenotypically using cefoxitin disc. Antibiotics susceptibility testing of the MRSA isolates was carried out using agar diffusion method and the multidrug resistance determined. Out of the 250 nasal samples collected, 41 (16.4%) were confirmed to be S. aureus, out of which 25(61.0%) were methicillin resistant. Students from Faculties of Science and Medicine harboured higher percentages of MRSA (69.2% and 60.0%, respectively) in their nasal cavity. Gentamicin (84%) and ciprofloxacin (72%) were the most active antibacterial agents against the MRSA isolates. High level of resistance was recorded amongst the MRSA isolates to amoxicillin (80.0%), cotrimoxazole (52.0%), erythromycin (32.0%) and streptomycin (32.0%).Multidrug resistance was recorded in 48% of the MRSA isolates. In conclusion, there was a high prevalence of MRSA (61.0%) among Staff and students of Kaduna State University. Irrational use of antibiotics especially in the community and without prescription might be responsible for this.

Isolation and encapsulation of bacteriophage with chitosan nanoparticles for biocontrol of multidrug-resistant methicillin-resistant Staphylococcus aureus isolated from broiler poultry farms

This study was divided into two parts. The first part, the determination of methicillin-resistant Staphylococcus aureus (MRSA) prevalence in 25 broiler chicken farms, with the detection of multidrug resistant MRSA strains. The prevalence of MRSA was 31.8% (159 out of 500 samples) at the level of birds and it was 27% (27 out of 100) in the environmental samples. The highest antimicrobial resistance of the recovered MRSA strains was recorded to streptomycin (96%). All isolates (100%) had multidrug resistance (MDR) to four or more antibiotics with 16 distinct antibiotic resistant patterns, and multiple antibiotic resistance index (MARI) of 0.4–1. The second part, implementing novel biocontrol method for the isolated multidrug resistant MRSA strains through the isolation of its specific phage and detection of its survival rate at different pH and temperature degrees and lytic activity with and without encapsulation by chitosan nanoparticles (CS-NPs). Encapsulated and non-encapsulated MRSA phages were characterized using transmission electron microscope (TEM). Encapsulation of MRSA phage with CS-NPs increasing its lytic activity and its resistance to adverse conditions from pH and temperature. The findings of this study suggested that CS-NPs act as a protective barrier for MRSA phage for the control of multidrug resistant MRSA in broiler chicken farms.

The Prevalence and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Before and After the COVID-19 Pandemic in a Tertiary Saudi Hospital.

Methicillin-resistant Staphylococcusaureus (MRSA) has become a major public health problem all over the world. After the 2019 coronavirus illness (COVID-19), the pandemic may have influenced research priorities and resource allocation, potentially affecting the ability to monitor MRSA trends. The study aimed to evaluate the prevalence of S. aureus, including MRSA infections, and their antimicrobial susceptibilities over the years 2019 and 2020 in a tertiary hospital in Makkah City, KSA. A total of 2128 and 1515 laboratory (lab) samples were collected during the years 2019 and 2020, respectively. From these samples, the prevalence of S. aureus, including MRSA, and their antibiotic susceptibility were identified using standard, automated, and molecular microbiological methods. The present study shows that the lab prevalence ofall S. aureus during 2019 was found to be 35.5%, of which MRSA was 44.8%. During 2020, the frequency of S. aureus strains was 16%, of which MRSA was 41.2%. The most common MRSA isolated during both years were colonizing pus swabs and urine samples. The results showed that MRSA susceptibility against antimicrobial agents in 2019 was as follows: vancomycin (100%), linezolid (100%), trimethoprim-sulfamethoxazole (88%), and doxycycline (34.2%). The MRSA strains isolated during 2020 were as follows: vancomycin (100%), linezolid (96%), trimethoprim-sulfamethoxazole (100%), and doxycycline (24.3%). There was no significant difference in the incidence and antimicrobial resistance rates of MRSA over the two years. It was concluded that the prevalence rates of MRSA have not increased in 2020 when compared to 2019. Vancomycin, linezolid, trimethoprim-sulfamethoxazole, and doxycycline remain susceptible to the positive collected MRSA strains. There was no significant difference between the prevalence and antimicrobial resistance rates of MRSA between 2019 and 2020. Continued research efforts are needed to address this persistent public health threat. Strategies to control the spread of MRSA should include early detection of MRSA and surveillance, even during pandemics.

Prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) at a maternity and children hospital in Saudi Arabia: A cross-sectional study

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) pathogens are considered a serious global health threat, leading to increased mortality and antimicrobial resistance. Rates in Saudi Arabia remain high, necessitating continuous surveillance. This study investigates MRSA prevalence and susceptibility at a Saudi maternity and children's hospital. MethodA cross-sectional study was conducted on pediatric (<18 years) and maternal patients with S. aureus infection from Jan. 2020 to March. 2022. Bacterial strains were obtained from patient’s clinical specimens and was identified by standard method. The BD Phoenix™ M50 was used for antibiotic susceptibility tests and MRSA detection. Data were analysed using descriptive and inferential statistics (Chi-square test) with SPSS software. ResultsOut of 152 S. aureus cases, 114/152 (75 %) were pediatric and 38/152 (25 %) were maternal patients. The overall MRSA infection was 69/152 (45.4 %). Among pediatrics, 31/54 (57.4 %) MRSA cases were female; over 30/54 (56 %) were under 1 year old; and most MRSA infections were obtained from skin 29/54 (53.7 %) compared to other sites of infections (p = 0.024). Among maternal cases, 15/38 (39.5 %) were MRSA, primarily from wound infections 14/15 (93.3 %) compared to other sites of infections (p = 0.39). All MRSA isolates were sensitive to vancomycin and linezolid. While 51/60(85 %) were sensitive to Trimethoprim/ sulfamethoxazole. ConclusionThis investigation found a high prevalence of MRSA among pediatrics and maternal inpatients, indicating a significant burden. All MRSA isolates were susceptible to vancomycin but demonstrated variable sensitivity to other antibiotics. These findings highlight the need for ongoing surveillance, infection control strategies, and research into alternative treatment options to combat this major public health threat.

Distribution of antimicrobial resistance genes of methicillin-resistant Staphylococcus aureus isolated from animals and humans in Yogyakarta Indonesia

Background and Aim: Methicillin-resistant Staphylococcus aureus (MRSA) has been known as a highly pathogenic bacteria in animals and humans, which is still becoming a global health issue. The prevalence of MRSA infection continues to increase worldwide and has become a global concern as a dangerous zoonotic disease. The World Health Organization estimates that by 2050 MRSA will be the leading cause of death. This study aimed to estimate the prevalence of MRSA in S. aureus isolates of veterinary and human origin in Yogyakarta, Indonesia. Materials and Methods: A total of 42 cases of S. aureus infection were examined in this study, consisting of nine isolates from cattle, five from goat, and 28 from human. All isolates were confirmed as S. aureus based on bacterial culture and detection of 23S rRNA and thermonuclease nuc gene by polymerase chain reaction (PCR). Results: Among 42 isolates, 35 isolates (83.3%) were identified as MRSA by PCR positive of mecA gene encoding methicillin resistance. Most MRSA strains were found in human isolates (100%), followed by cattle isolates (55.5%) and goats (40%). All MRSA strains were also multi-resistant to penicillin (blaZ gene) and tetracycline (tetK, and tetM genes) with a prevalence of about 98%. Conclusion: MRSA prevalence in humans and animals has increased significantly in Yogyakarta, Indonesia, compared to the previous study. The antimicrobial resistance pattern of MRSA animal isolates tends to be similar to humans and, thus, raises public health concerns about MRSA zoonotic spread. Keywords: animal, antimicrobial resistance, human, methicillin-resistant Staphylococcus aureus, Staphylococcus aureus.

Methicillin-Resistant Staphylococcus aureus among Poultry in Umuahia, Nigeria

Methicillin-resistant Staphylococcus aureus (MRSA) among poultry was investigated. Methicillin-resistant S. aureus (MRSA) poses serious public health issues worldwide and infections resulting from these organisms present difficult therapeutic challenges. A total of 250 swab samples were collected from the skin, cloaca, and egg shells of chickens as well as from feeds, droppings and environment of poultry farms located in rural communities of Umuahia, Nigeria. The respective specimens were inoculated onto mannitol salt agar using the streak plate technique. Inoculated plates were incubated at 35–37 °C for 18 to 24 hours aerobically. Bacterial colonies showing typical characteristics of S. aureus (i.e., golden yellow pigmentation on mannitol salt agar resulting from the fermentation of mannitol) were subcultured onto freshly prepared nutrient agar plates to obtain pure colonies. The pure isolates were characterized by Gram staining, biochemical testing and molecular identification. Antimicrobial assays of the isolates were performed using various antibiotics. Out of 250 samples, 66 isolates of S. aureus were obtained. The antibiotic resistant pattern of S. aureus varied. The isolates were highly resistant to tetracycline, ampicillin, erythromycin and cefuroxime. The multiple antibiotic resistant (MAR) profile of S. aureus showed that 20(30.3%) exhibited MAR to nine antibiotics while 19(28.8%) isolates exhibited MAR to ten antibiotics. Out of the 66 isolates, 24(36.3%) isolates were Methicillin-Resistant S. aureus (MRSA). The highest prevalence of MRSA was obtained from skin and cloaca samples. This study has confirmed the existence of MRSA in poultry farms within the study area. The presence of S. aureus and MRSA in poultry poses a great challenge to food security, because most of the poultry where samples were collected in this study are small holder farms that supply chickens to the public for human consumption as a source of protein.

Zoonotic linkage and environmental contamination of Methicillin-resistant Staphylococcus aureus (MRSA) in dairy farms: A one health perspective

Methicillin-Resistant Staphylococcus aureus (MRSA) is a ubiquitous public health challenge, with its prevalence in human, animal, and environmental interfaces posing significant concerns. This study aimed to characterize and detect the zoonotic linkages of MRSA within the cow-environment-human interfaces in dairy farms to address the One Health perspective. A comprehensive investigation, involving 636 samples (an equal number of raw milk and cow nasal swab samples, along with varying numbers of human nasal swab and environmental samples), revealed an overall MRSA prevalence of 13.4% (n = 271/636). Notably, environmental samples exhibited the highest prevalence (19.3%), emphasizing the potential role of farm surroundings in MRSA transmission, while the lowest prevalence was found in raw milk at 11.8% (n = 31/263). The prevalence in cow nasal swabs and human nasal swabs was 13.3% (n = 35/263) and 15.1% (n = 8/53), respectively. Multiplex PCR analysis revealed the presence of different Staphylococcal enterotoxin (SEa, SEb, SEc, and SEd), and exfoliative toxin-producing genes (Eta, Etb) within the MRSA isolates underlining their potential to induce public health threats. All MRSA isolates exhibited complete resistance to Oxacillin (100%) and Amoxicillin (100%), while the highest sensitivity was observed for Vancomycin (85.8%). Furthermore, these MRSA strains demonstrated varying degrees of resistance to other commonly used antimicrobial drugs, including Cefoxitin (75.3%), Ceftarolin (71.2%), Sulfamethoxazole-Trimethoprim (63.5%), Ciprofloxacin (60%), and Gentamicin (49.5%). Detection of MRSA in cow, human, and environmental samples within the same farm vicinity highlights the risk of zoonotic transmission of MRSA from cows to humans through environmental interfaces. Phylogenetic analysis of the mecA gene in MRSA isolates from all sources within the same farm revealed a high similarity index (>84%) among them suggesting a shared evolutionary origin. Moreover, the MRSA isolates from milk samples showed a close evolutionary relationship with isolates from Kenya and Brazil, while the isolates from humans and the environment displayed noticeable resemblance to isolates from several Asian countries. The findings emphasize the importance of collaborative efforts under the One Health framework to address this multifaceted issue and ensure the safety of our food supply and public health.

The Prevalence, Epidemiological, and Molecular Characterization of Methicillin-Resistant Staphylococcus aureus (MRSA) in Macau (2017-2022).

Macau, recognized as a global tourism hub and the world's most densely populated region, provides a unique environment conducive to methicillin-resistant Staphylococcus aureus (MRSA) transmission in healthcare and community settings, posing a significant public health concern both locally and globally. The epidemiology and molecular characteristics of MRSA in the distinct city of Macau remain largely unelucidated. This five-year longitudinal study (2017-2022) examined the local prevalence and molecular typing of MRSA in Macau, with future MRSA type distribution predicted through ARIMA modeling. We subsequently analyzed the epidemiological characteristics of MRSA, including specimen source, clinical department, collection year, season, patient age, sex, and the annual number of tourists. Comprehensive antibiotic resistance profiles of the strains were also assessed. Of 504 clinically isolated S. aureus strains, 183 (36.3%) were identified as MRSA by the cefoxitin disk diffusion method and validated through multi-locus sequence typing (MLST). The MRSA detection rate showed an upward trend, increasing from 30.1% in 2017 to 45.7% in 2022. SCCmec type IV was predominant (28.9%), followed by types II (25.4%), III (22.1%), and V (22.1%). The primary sources of MRSA isolates were sputum (39.2%) and secretions (25.6%). Older age emerged as a risk factor for MRSA infection, whereas no significant associations were found with seasonal variations, gender, or the annual number of tourists. Despite displaying universal resistance to cefoxitin, oxacillin, and benzylpenicillin, MRSA isolates in Macau remained fully sensitive to vancomycin, tigecycline, quinupristin, nitrofurantoin, and linezolid. Continuous surveillance and analysis of MRSA distribution in Macau could provide invaluable insights for the effective management of MRSA prevention and control measures within healthcare settings.

Community-acquired Methicillin-resistant Staphylococcus Aureus Pneumonia: A Diagnostic Challenge

Even though methicillin-resistant Staphylococcus aureus (MRSA) is considered a source of nosocomial pneumonia, a few cases have likewise depicted instances of community-acquired pneumonia (CAP) among healthy individuals that were caused by MRSA. Mostly CA-MRSA causes skin and soft tissue infection but can be responsible for severe invasive infection with higher morbidity. Invasive CA-MRSA requires aggressive management to prevent complications. CA-MRSA strains are now recognized as distinct clonal entities that differ from traditional hospital-acquired MRSA (HA-MRSA) strains. The increasing prevalence of MRSA in the community is an important public health problem, which needs increased vigilance in the diagnosis and management of suspected and confirmed staphylococcal infections. We present an intense case of CAP brought about by MRSA with impending respiratory failure in a 19-year-old male, who presented with acute febrile illness with swelling over lips with no co-morbid and insignificant past medical history. Through this case, we intend to increase awareness among physicians about the growing role of CA-MRSA in the population; they should be meticulous in treating patients with CA-MRSA, and be aware of the complications of this disease and the appropriate empiric and target antibiotics regimen for such infections, whenever it is suspected, to enhance better clinical outcomes.

Prevalence of livestock associated methicillin resistant Staphylococcus aureus (La-mrsa) in domestic livestock of Dharan, Nepal

Introduction: Methicillin Resistant Staphylococcus aureus (MRSA) infection has drawn a lot of attention since studies suggested that animals may act as reservoirs for human infection. Over the past 20 years, MRSA infections have become more prevalent worldwide. MRSA was initially only discovered in humans, but later it was discovered in animals as well. Objectives: The study aimed to determine the prevalence of LA-MRSA in domestic livestock of Dharan, Nepal. Methods: Overall, 320 skin swab samples of cattle (cows) were collected by swabbing the skin of cattle aseptically with a sterile cotton swab and the samples were transported to the laboratory in a cold chain. The samples were streaked in Mannitol salt agar(MSA) containing oxacillin concentration of 6mg/L and incubated at 37°C for 24 hours. Staphylococcus aureus colonies were identified based on cultural characteristics on MSA plates (golden yellow colonies), Gram’s reaction, and positive results for coagulase and catalase test. The purified isolates of MRSA were subjected to antibiotic susceptibility tests and Biofilm formation. Results: MRSA was found to be prevalent in 10% of cattle. Antibiotic-resistant tests reported that MRSA was found to be sensitive to chloramphenicol 12(37.5%) followed by ceftriaxone 12 (37.25%), gentamycin 9(28.12%), cefotaxime 4(12.5%), while 100% of MRSA were resistant to penicillin and vancomycin. The moderate biofilm-forming MRSA was 5(15.625%), followed by 3(9.375%) weak biofilm producers and 24(75%) were negative towards biofilm formation. Conclusion: The prevalence of MRSA (10%) and Vancomycin-Resistant Staphylococcus aureus (100% VRSA) in cattle shows the need for regular surveillance. Chloramphenicol can be a treatment of choice for MRSA infections. However, emerging VRSA is a serious epidemiological issue that needs to be addressed properly. Therefore, Healthcare organizations must adopt precise criteria to control and prevent MRSA infection..

Exploring the Antibacterial Potential of 2-Ethylacridine from Salacia chinensis: Insights into its Mechanism against Methicillin-Resistant Staphylococcus aureus (MRSA)

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a growing health issue in India, leading to higher healthcare costs and increased morbidity and mortality rates. The prevalence of MRSA in both community and hospital settings has been on the rise, necessitating the exploration of alternative treatments. Aim: This study aimed to isolate secondary metabolites from Salacia sinensis and determine their mode of action against MRSA through molecular docking. Methodology: The study involved the collection of plant samples from Tamil Nadu, India, and the extraction of phytochemicals using methanol and chloroform. GCMS analysis was conducted to identify the bioactive compounds, and molecular docking analysis was performed to assess the antibacterial activity of 2-Ethylacridine against the multi-drug resistance protein (nora) of S.aureus. Results: The qualitative phytochemical screening of S. chinensis extracts revealed the presence of proteins, carbohydrates, flavonoids, saponins, sterols, terpenoids, and alkaloids. GCMS analysis identified bioactive compounds namely 2-Ethylacridine and Squalene. Molecular docking analysis demonstrated a high binding affinity (-6.8) of 2-Ethylacridine to the Multi-drug resistance protein (nora) of S.aureus. Implications: The study provides insights into the antibacterial mechanism of 2-Ethylacridine against MRSA, suggesting its potential as a promising antibacterial agent. These findings have implications for the development of novel antibacterial agents targeting multi drug resistance proteins and addressing antibiotic-resistant strains.

Evaluation of In-Vitro Activity of Ceftaroline Against Methicillin-Resistant Staphylococcus aureus Clinical Isolates.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital and community-acquired infections. Fewer drugs, such as vancomycin, teicoplanin, and daptomycin, are effective against it, but they come with high toxicity. Fifth-generation cephalosporins like ceftaroline and second-generation cefuroxime are effective against MRSA. Limited studies are available on ceftaroline resistance in the literature. This study was undertaken to determine ceftaroline resistance in MRSA in a tertiary care hospital in Eastern India. A cross-sectional, hospital-based study was carried out with MRSA isolates obtained from various clinical samples of patients. Identification of the isolates to the species level was performed by an automated Vitek system, and selected samples were genotypically confirmed by detecting the mecA gene via real-time PCR. Out of a total of 334 Staphylococcus aureus isolates examined in this study, the prevalence of MRSA was seen in 59.3% (198/334), and methicillin-sensitive Staphylococcus aureus was in 40.7% (136/334). Of the total 198 MRSA isolates, ceftaroline intermediate MRSA was seen in 8.6% (17/198), and ceftaroline sensitive MRSA was in 91.4% (181/198), respectively. Among the 17 ceftaroline intermediate MRSA isolates, 88.2% (15/17) showed aminimum inhibitory concentration (MIC) of 2 µg/ml, and 11.8% (2/17) showed an MIC of 3 µg/ml. All the remaining 91.4% (181/198) isolates were sensitive to ceftaroline and showed an MIC ≤1 µg/ml. Real-time PCR confirmed the presence of the mecA gene in MRSA isolates. In this present study, not a single isolate was resistant to ceftaroline, suggesting that it, being a safer drug, can be used in place of glycopeptides such as vancomycin or teicoplanin and linezolid, where resistance has already been detected. The rational use of ceftaroline could be useful in clinical settings, and further studies will confirm the findings.

Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus among Patients Diagnosed with Surgical Site Infection at Four Hospitals in Ethiopia.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of severe surgical site infections (SSI). The molecular epidemiology of MRSA is poorly documented in Ethiopia. This study is designed to determine the prevalence of MRSA and associated factors among patients diagnosed with SSI. A multicenter study was conducted at four hospitals in Ethiopia. A wound culture was performed among 752 SSI patients. This study isolated S. aureus and identified MRSA using standard bacteriology, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), and cefoxitin disk diffusion test. The genes mecA, femA, vanA, and vanB were detected through PCR tests. S. aureus was identified in 21.6% of participants, with 24.5% of these being methicillin-resistant Staphylococci and 0.6% showing vancomycin resistance. Using MALDI-TOF MS for the 40 methicillin-resistant Staphylococci, we confirmed that 31 (77.5%) were S. aureus, 6 (15%) were Mammaliicoccus sciuri, and the other 3 (2.5%) were Staphylococcus warneri, Staphylococcus epidermidis, and Staphylococcus haemolyticus. The gene mecA was detected from 27.5% (11/40) of Staphylococci through PCR. Only 36.4% (4/11) were detected in S. aureus, and no vanA or vanB genes were identified. Out of 11 mecA-gene-positive Staphylococci, 8 (72.7%) were detected in Debre Tabor Comprehensive Specialized Hospital. Methicillin-resistant staphylococcal infections were associated with the following risk factors: age ≥ 61 years, prolonged duration of hospital stay, and history of previous antibiotic use, p-values < 0.05. Hospitals should strengthen infection prevention and control strategies and start antimicrobial stewardship programs.

Prevalence and antibiotic susceptibility profile of Staphylococcus aureus in clinical and subclinical mastitis milk samples

Background: Staphylococcus aureus is the most commonly isolated bacterial pathogen in clinical and subclinical mastitis among cows. This study aimed to investigate the prevalence of Staphylococcus aureus, including MRSA (Methicillin-resistant Staphylococcus aureus), in cows with clinical and subclinical mastitis in Cumilla and Chattogram regions. Additionally, antimicrobial resistance patterns were identified. Methods: A total of 429 milk samples were collected from different teats of 125 cows with clinical and subclinical mastitis across 15 farms. Standard bacteriological methods were applied to isolate and identify Staphylococcus aureus. Confirmation of Staphylococcus aureus was achieved through PCR for the presence of the nuc gene. Antimicrobial susceptibility testing was conducted for 11 antimicrobials. Isolates showing resistance to cefoxitin and oxacillin underwent mecA gene screening to identify MRSA. Multivariable logistic regression models were used to identify risk factors associated with the presence of Staphylococcus aureus Results: The study revealed that 13.54% (95% CI, 5.00–38.78%) of mastitis-infected cows tested positive for Staphylococcus aureus. Staphylococcus aureus isolates showed the highest resistance to penicillin, cloxacillin, and streptomycin (61.54%, 53.85%, and 53.85%, respectively), while manifesting the least resistance to ciprofloxacin, ceftriaxone, and sulfamethoxazole + trimethoprim (92%, 77%, and 77%, respectively), and gentamycin (69.23%). The prevalence of MRSA was 2.08% (95% CI, 1.55–38.34%). Conclusion: This study represents the first report of MRSA in clinical and subclinical mastitis milk samples in Bangladesh. The findings emphasize the importance of ongoing monitoring of Staphylococcus aureus and MRSA in mastitis cases, considering their prevalence and patterns of antimicrobial resistance.

Molecular epidemiology and change trend of methicillin-resistant Staphylococcus aureus from invasive infections of a hospital in Hangzhou from 2012 to 2018.

The disease caused by methicillin-resistant Staphylococcus aureus (MRSA) is a global public health challenge that threatens society and patients seriously. Therefore, the molecular epidemiology and change trend of MRSA is essential for the control and treatment of diseases caused by the pathogen in their regions. To explore molecular epidemiology of MRSA in Hangzhou, we collected 162 MRSA isolates from 2012 to 2018, conducted the antimicrobial susceptibility and used polymerase chain reaction(PCR) to test the molecular typing including multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec), staphylococcal protein A (spa A) and Panton-Valentine leucocidin (PVL). All the strains was divided into community-associated MRSA (CA-MRSA) or hospital-associated MRSA (HA-MRSA). 162 MRSA isolates were divided into 16 STs and 30 spa types. The major ST type was ST5 (96/162, 59.3%) and the predominant spa type was t311 (83/162, 51.2%). Five SCCmec types were found and the most common SCCmec type was type II (101/162, 61.7%). ST5-II-t311 was the predominant MRSA clone. And the prevalence of ST5 MRSA gradually declined from 2014 to 2018 but the prevalence of ST59 MRSA significantly increased. At the same time, livestock-associated methicillin-resistant Staphylococcus aureus(LA-MRSA) ST398 and ST9 were detected. Twenty-eight isolates were PVL gene positive (28/162, 17.3%). The most prevalent PVL-positive clone was ST59-IVa-t437. Comparing with HA-MRSA, CA-MRSA had a lower probability of ST5 (9.1% vs 67.1%, P=0.000) but a higher probability of ST59 (63.6% vs 11.4%, P=0.000), not only that, it was more likely to carrying PVL-positive gene (36.4% vs 14.3%, P=0.028). In summary, the molecular types of MRSA were getting complex over time. ST5-II-t311 was the predominant clone of MRSA isolate with a downward incidence from 2014 to 2018. ST59 MRSA strains, which is thought community related strain are spreading into hospitals and has an upward incidence from 2014 to 2018.

On-farm epidemiology, virulence profiling, and molecular characterization of methicillin-resistant Staphylococcus aureus at goat farms

Antimicrobial resistance (AMR) becomes a challenging issue that limits the therapeutic options for both veterinary and public health professionals. The current study aimed to investigate the on-farm epidemiology, antibiotics resisting profiling, virulence analysis, and molecular detection of methicillin-resistant Staphylococcus aureus (MRSA) at the caprine-human interface. A total of 768 goat milk samples and 94 skin swabs from farm personnel were collected from 30 goat flocks and processed for isolation of S. aureus. The study isolates were confirmed as MRSA based on the oxacillin and cefoxitin disc diffusion test and the presence of mecA gene. MRSA isolates of goats and human origin were characterized and further evaluated for the presence of virulence genes responsible for intramammary infections and public health hazards. The results revealed 26.82 % and 27.79 % goat milk samples and human samples positive for S. aureus, respectively. A higher MRSA prevalence of 35.92 % and 10.71 % was found in goat and human isolates respectively. The phylogenetic analysis revealed a lesser extent of homology in mecA gene of S. aureus isolates at the caprine-human interface. Moreover, this study revealed strong evolutionary connection between the study isolates and MRSA isolates of Pakistani cattle and buffalo while the in-silico protein analysis showed that all sequences have the same protein motifs resembling penicillin binding protein 2a. The risk factors analysis revealed that teat length, drainage system, hygienic measures during milking, use of teat dip, teat injury, and veterinary services were significantly associated with subclinical mastitis in goats. A total of 43.24 % of local MRSA isolates showed multi-drug resistance (MDR). The isolates showed higher resistance to oxytetracycline followed by gentamicin and vancomycin while moxifloxacin, and linezolid were among the susceptible antibiotics. Local MRSA isolates carried virulence markers (nuc and coag genes) and biofilm-associated icaA (43.24 %) and icaD (29.73 %) genes which are responsible for the intramammary infection. The local isolates also carried the virulence genes of public health concern including the enterotoxin C (sec) gene (24.3 %), enterotoxins B (seb) gene (5.41 %), and enterotoxin D (sed) gene (2.7 %). Enterotoxins A (sea) and E (see) genes were not detected in any isolate. The study concluded that MRSA is an emerging and prevailing pathogen in dairy goats with a high potential to transmit to associated human beings. The presence of a variety of virulence factors as well as the associated antibiotic resistance makes MRSA a potential threat at animal-human interface and thus demands further research.

MOLECULAR IDENTIFICATION AND ANTIBIOGRAM OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS FROM WOUNDS OF BOTH IN- AND OUT-PATIENTS AT UNIVERSITY OF BENIN TEACHING HOSPITAL (UBTH), BENIN CITY, NIGERIA

Methicillin-resistant Staphylococcus aureus (MRSA) stands as a prominent bacterial pathogen associated with various human infections, characterized by its remarkable ability to rapidly develop resistance to multiple antibiotics. The study aimed to characterize MRSA isolated from wounds among hospital patients. A total of eighty-seven unique S. aureus isolates were obtained from wound cultures collected from patients at the University of Benin Teaching Hospital (UBTH) in Benin City, Nigeria. These samples underwent assessment for methicillin resistance through conventional cultural methods, and detection of methicillin resistance (mecA) and S. aureus specific (nuc) genes using PCR amplification. The MRSA isolates underwent assessment for antimicrobial resistance through disc diffusion testing and for virulence factors using phenotypic testing procedures. An overall prevalence of 34/87 (39.1%) MRSA isolates was recorded. Based on the source of the isolate, the distribution of MRSA isolates from in-patients was 22/56 (39.3%) and out-patients was 12/31 (39.7%). Total Panton valentine leucocidin (PVL) screening revealed 11/34 (32.4%). All the isolates were resistant to penicillin 34/34 (100%) and cefepime 34/34 (100%). Lower level of resistance was demonstrated towards ciprofloxacin 3/34 (8.8%). Overall, every isolate displayed resistance to at least three antibiotics, resulting in a multiple antimicrobial resistance index of at least 0.33. The total virulence factors observed were beta-hemolytic activity 22/34 (64.7%), protease activity 14/34 (41.2%), and lipase activity 19/34 (55.9%). This study emphasized the significance of regularly monitoring MRSA prevalence within both the hospital and the local community. Therefore, the need for better intervention and continuous enlightenment on risks associated with the abuse...

Comparison of prevalence and risk factors for methicillin-resistant &lt;i&gt;Staphylococcus aureus&lt;/i&gt; in two tertiary institutions, southern Nigeria.

Methicillin-resistant Staphylococcus aureus (MRSA) is an incessant public health challenge with a rising trend in community infection among students. This study compared the prevalence and risk factors for MRSA nasal colonization among students in two tertiary institutions in Southern(east and west) Nigeria. One hundred nasal swab samples were collected from healthy university students and questionnaire aided in the retrieval of demographic and possible risk data. Staphylococcus aureus isolates were identified using morphological and biochemical approach. MRSA was detected phenotypically using both cefoxitin test and double disk synergy test. The antibiotic susceptibility test was done on the MRSA isolates against 9 antibiotics. A total of18% (18/100) and 6% (6/100) Staphylococcus aureus and MRSA isolates was detected respectively. Of which, 8% (4/50) and 4% (2/50) MRSA strains was found in south eastern and south western Nigeria respectively (p = 0.036). The mean age of the students was 21.4 years ±1.81. Overall, the age-group and gender with the highest MRSA colonization was 20-24 years and females respectively. Significant association was found between MRSA colonization and regular hospital visitation, touching of nose/face, and use of antibiotics without doctor's prescription (P &lt;0.05) in both institutions. A total of 100% of the isolates were resistant to clotrimazole. High prevalence (67%) of multi-drug resistance was observed. The prevalence of MRSA in both institutions had significant difference; with the risk factors: regular hospital visitation, touching of nose/face and indiscriminate use of antibiotics among the students.

Molecular Detection of Hospital-Acquired Methicillin-Resistant Staphylococcusaureus Isolated From Teaching Hospitals in Damascus, Syria

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen responsible for hospital-acquired infections (HAIs). Accurate MRSA diagnosis is of paramount importance to facilitate early and effective treatment and to manage its transmission effectively. The primary objective of our study was to determine the precise prevalence of hospital-acquired MRSA (HA-MRSA) in select teaching hospitals in Damascus by detecting the presence of the mecA gene. Methods: One hundred Staphylococcus aureus isolates were collected from various clinical specimens obtained from inpatients admitted to three major teaching hospitals in Damascus, Syria, including Al-Moussat, Al-Assad, and Tishreen Military Hospitals. These patients met the established criteria for HAIs. The isolates were collected between December 2021 and August 2022. Genus and species confirmation were conducted via polymerase chain reaction (PCR), employing the 16SrDNA gene specific to the Staphylococcus genus and the nuc gene specific to S. aureus. Methicillin resistance was assessed using cefoxitin disc diffusion (CDD) in accordance with Clinical and Laboratory Standards Institute (CLSI) recommendations. The presence of the mecA gene was also detected through PCR. Results: Out of the collected isolates, 67% exhibited resistance to cefoxitin, as determined by the CDD, while 66% were found to be positive for the mecA gene. CDD demonstrated a sensitivity of 100% and a specificity of 97%. Conclusion: This investigation revealed a notably high incidence of HA-MRSA infections within the teaching hospitals under scrutiny. The CDD method displayed significant sensitivity and specificity, making it a dependable alternative to the mecA PCR for MRSA detection. This finding holds substantial importance for the effective implementation of infection control initiatives and strategies aimed at eradicating MRSA and curtailing its spread within our hospital facilities.