Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Nasal Carriage and Associated Factors of Methicillin-Resistant Staphylococcus Aureus Among Medicine and Health Science Students of Arba Minch University, Arba Minch, Ethiopia

Individuals with Methicillin-Resistant Staphylococcus aureus (MRSA) colonized nasal cavities were at greater risk of developing the infection and can serve as potential reservoirs of transmission. Aim of this study is to determine the extent of nasal carriage and associated factors linked to MRSA in medical and health science students of Arba Minch University (AMU), Ethiopia. An institution based cross-sectional study was conducted at AMU from 01st August through 30th November, 2020. A systematic sampling technique was used to recruit the participants. Socio-demographic data were collected using a structured questionnaire. Nasal swabs were collected and S. aureus were identified following standard microbiological methods. Methicillin resistance was tested using cefoxitin disk and antimicrobial susceptibility tests were performed by Kirby-Bauer disk diffusion. Biofilm forming ability was phenotypically detected by micro-titer plate assay. Descriptive statistics and multivariable logistic regression analysis were done by Statistical Package for Social Service (SPSS) version 25. Overall prevalence of Staphylococcus aureus and MRSA were 27.1% (70/258) and 7.4% (19/258) respectively. Methicillin-Resistant S. aureus carriage was higher among medical interns, 16.9% (11/65); isolates were co-resistant to antibiotics, such as trimethoprim-sulfamethoxazole (63.2%) and tetracycline (48.4%). Multidrug resistance (MDR) was observed among 52.6% (10/19) of the isolates. Besides, 31.4% (6/19) of MRSA were biofilm producers and all of them were MDR. Multivariable analysis showed that students having >2 years of mean exposure to hospital [p= 0.048, AOR: 4.99, 95% CI: 1.01-24.66] and those who share clothing and sports equipment [p=0.017, AOR: 5.43, 95% CI: 1.35-21.83] were statistically significant. The overall prevalence of nasal MRSA among students were comparatively lower than that observed in other studies done in Ethiopia itself. An alarming factor is that, 60% of MDR-MRSA were biofilm producers.

Emergence of methicillin resistance predates the clinical use of antibiotics

The discovery of antibiotics more than 80 years ago has led to considerable improvements in human and animal health. Although antibiotic resistance in environmental bacteria is ancient, resistance in human pathogens is thought to be a modern phenomenon that is driven by the clinical use of antibiotics1. Here we show that particular lineages of methicillin-resistant Staphylococcus aureus—a notorious human pathogen—appeared in European hedgehogs in the pre-antibiotic era. Subsequently, these lineages spread within the local hedgehog populations and between hedgehogs and secondary hosts, including livestock and humans. We also demonstrate that the hedgehog dermatophyte Trichophyton erinacei produces two β-lactam antibiotics that provide a natural selective environment in which methicillin-resistant S. aureus isolates have an advantage over susceptible isolates. Together, these results suggest that methicillin resistance emerged in the pre-antibiotic era as a co-evolutionary adaptation of S. aureus to the colonization of dermatophyte-infected hedgehogs. The evolution of clinically relevant antibiotic-resistance genes in wild animals and the connectivity of natural, agricultural and human ecosystems demonstrate that the use of a One Health approach is critical for our understanding and management of antibiotic resistance, which is one of the biggest threats to global health, food security and development.

Isolation and antimicrobial resistance of coagulase-negative staphylococci recovered from healthy tortoises in Minas Gerais, Brazil

ABSTRACT: In the last few decades, there has been a global increase in the adoption of reptiles as companion animals, mainly turtles and tortoises. Considering the popularity of reptiles as pets in Brazil, and a notable lack of data about potentially pathogenic staphylococci in these animals, this study isolated and evaluate the antimicrobial susceptibility of staphylococcal species from healthy tortoises (Chelonoidis carbonaria) in Brazil. During a 12-month period (February 2019 to February 2020), cloacal swabs from 66 healthy tortoises were collected at the Wild Animals Screening Center in Belo Horizonte, Minas Gerais, Brazil. The swabs were plated onto mannitol salt agar for staphylococci isolation, and species identification was performed using MALDI-TOF MS. Antimicrobial susceptibility was investigated using the disk diffusion method, and the presence of the mecA gene was investigated by PCR to detect methicillin resistance. Of the tested animals, 72.7% were positive for staphylococcal isolation. All isolates were coagulase-negative staphylococci (CoNS), and Staphylococcus sciuri (81.3%), and S. xylosus (12.5%) were the most frequently isolated species. The majority of the isolates (56%) were resistant to at least one antimicrobial agent. A high frequency of resistance was observed for penicillin (35.5%) and tetracycline (29.1 %). All strains were susceptible to cefoxitin, chloramphenicol, ciprofloxacin, erythromycin, and gentamicin. All isolates were negative for the mecA gene. The present work suggests that healthy tortoises are mainly colonized by CoNS, especially S. sciuri. Half of the isolates were resistant to at least one antimicrobial, raising questions regarding the possible role of these animals as reservoirs of antimicrobial resistance genes.

IDENTIFICATION OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS USING TOUCHDOWN PCR AND PHENOTYPIC METHODS FROM PATIENTS AND HOSPITALS ENVIRONMENTS IN DIFFERENT IRAQI CITIES

The study was aimed to evaluate the prevalence of MRSA in some Iraqi hospitals and determine the most powerful methods for identification of MRSA, in order to achieve the, 278 samples were collected from different hospitals in Iraq in various intervals, 204 out of 287 were identified as Staphylococcus aureus by conventional cultural methods and microscopic characteristics and 177 isolates are identified as MRSA by using HiCrome MeReSa Agar Base medium, but 154 of 177 (87%) isolates are methicillin resistance in sensitivity test. MRSA isolates were highly resistant to β-lactam antibiotics and considered multidrug resistant (MDR) in percent of (94.9%). Touchdown PCR used to identify the isolates, 97.05% were identified as Staphylococcus aureus, while 80.88% as MRSA.

Prevalence of MRSA and Antimicrobial Susceptibility Staphylococcus aureus in Clinical Samples in National Capital Region, India

Background: Infections caused by Staphylococci are frequently linked to indwelling medical equipment. These are extremely difficult to treat with antibiotics. In India, the prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) varies from 30 to 70%, resulting in high mortality, increased economic burden, and high treatment failure in tertiary care hospitals. Rapid and reliable identification of MRSA is critical for infection management and avoiding the needless use of antibiotics. Materials and Methods: This prospective study was carried out in the Department of Microbiology, Santosh Medical College, Ghaziabad, from the 1st of August 2020 to the 31st of January 2021. MRSA isolates were screened and confirmed using standard methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Methicillin resistance, in Staphylococcus aureus strains, was evaluated using oxacillin/cefoxitin. The Kirby-Bauer disc diffusion technique was used to assess the antibiotic susceptibility pattern of all MRSA strains. Results: In this investigation, MRSA was identified in 29.4% of the 384 Staphylococcus aureus strains. When compared to females, men outnumbered females. Cefoxitin detects a greater amount of MRSA than oxacillin. In this investigation, the majority of MRSA was found in pus samples. Conclusion: MRSA prevalence is known to vary depending on geographical region, hospital type, investigated population, and technique of detection used. Given the clinical implications of MRSA infection and its fast transmission capability, MRSA strains must be monitored on a regular basis.

Coagulase Negative Staphylococci (CoNS): A Review

Coagulase-negative staphylococcus (CoNS) has gained more importance as pathogenic organism for infections in both human and animals. CoNS are especially prevalent in immunocompromised patients, critically ill patients, patients having invasive medical devices. The incidence of CoNS varied across different geographic locations in humans and animals. Also, there are varying antibiotic resistance patterns observed in CoNS species, with high methicillin resistance and cross resistance against many antibiotics. Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus xylosus are the most commonly reported species in various studies. Various virulence factors in CoNS are responsible for enhanced pathogenicity. Because of advancement in diagnostic techniques understanding of molecular mechanisms of CoNS pathogenicity is possible. Recent advances in identification and typing methods, virulence screening methods will help to assess true pathogenic potential of CoNS species. This review focuses on various CoNS species, their identification and virulence factors and clinical importance.

Staphylococcus aureus with inducible clindamycin resistance and methicillin resistance in a tertiary hospital in Nepal

Background Staphylococcus aureus is a global public health issue in both community and hospital settings. Management of methicillin-resistant S. aureus (MRSA) infections are tough owing to its resistance to many antibiotics. Macrolide-lincosamide-streptogramin B (MLSB) antibiotics are commonly used for the management of MRSA. This study was aimed to determine the occurrence of inducible clindamycin- and methicillin-resistant S. aureus at a tertiary care hospital in Kathmandu, Nepal. Methods A total of 1027 clinical samples were processed following standard laboratory procedures and antibiotic susceptibility testing of S. aureus was performed by disc diffusion method. MRSA isolates were detected phenotypically using cefoxitin disc, and inducible clindamycin resistance was detected phenotypically using the D-zone test. Results Of 1027 samples, 321 (31.2%) were culture positive, of which 38 (11.8%) were S. aureus. All S. aureus isolates were susceptible to vancomycin, and 25 (67%) of S. aureus isolates were multidrug-resistant. Similarly, 15 (39.5%) of S. aureus were MRSA and 14 (36.5%) were inducible clindamycin-resistant phenotypes. Conclusion Inducible clindamycin and methicillin resistance were common in S. aureus. This emphasizes that the methicillin resistance test and the D-zone test should be incorporated into the routine antibiotic susceptibility testing in hospital settings.

Immunofluorescence Targeting PBP2a Protein: A New Potential Methicillin Resistance Screening Test

The indiscriminate use of first-line drugs contributed to the spread of resistant bacteria, a major concern for both human and veterinary medicine. Methicillin resistance is acquired through the mecA gene, which encodes for the PBP2a protein and lends the resistance to β-lactams. Verifying the correspondence between gene harboring and protein expression and accelerating methicillin resistance diagnosis is critical to improve the management of antimicrobial administration and to reduce the spread of drug resistances. We tested the applicability of immunofluorescence targeting PBP2a protein to identify a new potential methicillin resistance screening test, ancillary to conventional culture methods. We collected 26 clinical Staphylococcus pseudintermedius (SP) isolates: 25 from canine pyoderma and 1 from dermatitis in a dog owner. SP is one of the most important etiological agents in canine pyoderma and can harbor the mecA gene. We performed PCR for mecA gene detection, broth microdilution (BMD) for phenotypic methicillin resistance, and immunofluorescence targeting PBP2a protein. Compared to the PCR as the gold standard, immunofluorescence showed an apparent prevalence of 34.6% vs. a true prevalence of 53.8%, with 100% specificity, 64.3% sensitivity, and 80.8% diagnostic accuracy. PBP2a expression showed isolate-dependent variability: in some isolates, most of the bacterial cells showed an intense and clearly membranous pattern, while in others only a few of them could be detected. Performing the assay in duplicate improved the diagnostic accuracy. Since the mecA gene is shared among the members of the Staphylococcus genus, the test can be applied to identify methicillin resistance independently from the staphylococcal species, both in human and animal samples. Being a rapid and easy method and providing the unique possibility to study the expression of PBP2a by directly visualizing the morphology, it could represent a new interesting tool for both research and diagnostics. To accelerate methicillin resistance diagnosis, it would be worth further testing of its performance on cytological samples.