Effects of Staphylococcus aureus hemolysin toxins on blood cells and association with skin and soft tissue infections

Staphylococcus aureus (S. aureus) is gram positive, catalase positive cocci which belongs to the family of Staphylococcaceae and is long known as clinical and foodborne pathogen. The emergence of multidrug resistance strain of S. aureus which is methicillin resistant S. aureus (MRSA) challenges the health care system because it can cause wide variety of hospital and community acquired skin and soft tissue infections which are difficult to treat. The virulence of S. aureus is because of different factors which includes toxins, enzymes and superantigens. S. aureus produce variety of exotoxins, enterotoxins and exfoliative toxins which contributes to the virulence of S. aureus. Hemolysin toxins produce by S. aureus strains are associated with different skin and soft tissue infections (SSTIs) and can cause the lysis of RBCs. Hemolysins are regulated by accessory gene regulator (agr) and is required for the enhanced expression of virulence factors secreted by S. aureus. Hemolysins have leucolytic activity and can help in iron scavenging from host. The most important toxin is alpha hemolysin which can induce the apoptosis and cause the lysis of epithelial cells, erythrocytes and keratinocytes. Human immune cells are affected by beta hemolysin and gamma hemolysin is a biocomponent toxin. Delta hemolysin is low molecular weight exotoxin which belongs to the class of phenol soluble modulins. Keywords: MRSA, Exotoxins, Hemolysins, SSTIs

MRSA Community-acquired Pneumonia: Non COVID-19 Related Bilateral Ground-glass Opacities

Methicillin-resistant staph aureus (MRSA) has been known to cause severe hospital-acquired infections with its multi-drug resistant nature. MRSA Infections could quickly escalate into severe sepsis resulting in death, if not recognized and treated abruptly. This pathogen uncommonly causes Community-Acquired Pneumonia (CAP), which can lead to under treatment due to delayed coverage with anti-MRSA antibiotics resulting in poor clinical outcome. We herein describe an unusual case of MRSA CAP during COVID-19 pandemic in an 80-year-old male who was unresponsive and found to be in septic shock, intubated outside the hospital setting, and then brought to intensive care unit for further management. Laboratory and radiographic studies revealed MRSA in sputum culture and extensive bilateral consolidation with bilateral ground glass opacities and pleural effusions on imaging. Our patient was successfully treated with linezolid and extubated within 48 hours with a favorable outcome. High index of suspicion and a timely coverage with anti-MRSA antibiotics would reduce mortality and lead to a better outcome in otherwise fatal infection. Keywords: MRSA; Community-acquired pneumonia; Respiratory failure; Critical care; Case report

Nasal carriage of methicillin-resistant Staphylococcus aureus among healthcare undergraduates in Malaysia

Staphylococcus aureus is a common component of skin flora of healthy adults. However, it can cause serious infections such as bloodstream infections, pneumonia, or bone and joint infections. Methicillin-resistant Staphylococcus aureus (MRSA) is known to cause hospital- (HA-MRSA) and community-acquired (CA-MRSA) infections worldwide. Asia is reported to have highest prevalence rates of HA-MRSA and CA-MRSA. As there were very less number of epidemiological studies being done in Malaysia, this study aimed to determine the prevalence of MRSA infection among the healthcare undergraduates who will be engaging with patients soon. We analyzed nasal swabs of students from a private medical institution in Klang Valley, Malaysia. Methicillin-resistance was accessed by sensitivity to the Oxacillin and Cefoxitin disks. In a total of 151 healthcare undergraduates, 117 of them were found positive for Staphylococcus aureus. Among the latter, 21 samples (13.9%) were resistant to Oxacillin and Cefoxitin. Our data shows significant high percentage of MRSA infection and therefore prevention strategies for MRSA need to be developed for the healthcare students before they engage with patients in clinic setting. Keywords: MRSA, nasal swab, healthcare undergraduates, Oxacillin.

Efektivitas Kombinasi Vankomisin dan Vitamin C terhadap Pertumbuhan MRSA (Methicillin Resistant Staphylococcus aureus) (Effectiveness of Vancomycin and Vitamin C Combination on MRSA (Methicillin Resistant Staphylococcus aureus) Growth)

Nephrotoxicity due to prolonged use of vancomycin becomes a big issue in patients with MRSA infections and the use of vitamin C has been proved to decrease this side effect. Vitamin C with its combination with antibiotic will halt MRSA growth by forming Reactive Oxygen Species (ROS). This study aimed to determine the effect of vancomycin and vitamin C combination in order to halt the MRSA growth and the minimum concentration of vitamin C which can decrease the Minimum Inhibitory Concentration (MIC) of vancomycin. This study used a quasi experimental design with 7 groups, 1 as negative control which only given vancomycin and 6 other groups which given vancomycin and vitamin C with following concentration 0,4; 0,8; 1,6; 3,2; 6,4; and 12,8 mg/mL. We used microdilution method with 4 repetitions to measure the MIC value. This study revealed that there were no difference between control and other groups, the MIC of vancomycin is 1 µg/mL. Combination effect was measured by Fractional Inhibitory Concentration Index (FICI) calculation which showed indifferent effect to all groups. This study concluded that combination of vancomycin and vitamin C effect has no difference with control group and by adding vitamin C until 12,8 mg/mL did not decrease MRSA growth. Keywords: MRSA, vancomycin, vitamin C, Minimum Inhibitory Concentration (MIC)

MRSA dan VRSA pada Paramedis RSUD Ratu Zalecha Martapura

Abstact: Staphylococcus aureus strains isolated from hospital generally been resistant to many antimicrobial-resistant strains of Staphylococcus aureus to vancomycin was rarely reported. Strains of Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial infections that are multiresistant to antibiotics. This study aims to determine the presence of bacteria Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Staphylococcus aureus (VRSA) on paramedics in the treatment room and the surgical ICU care hospitals Zalecha Martapura queen. This study used a descriptive survey method. The population in this study were nurses who worked in the surgical and ICU care that numbered 38 people. Sampling technique accidental sampling with a sample of 27 people. The survey results revealed 27 positive samples of Staphylococcus aureus 14 people, there is a sensitivity test results of 7 samples were resistant to cefoxitin (MRSA 26%), 4 samples were resistant to oxacilin and 7 samples were resistant to vancomycin (VRSA 26%). Concluded there is MRSA and VRSA in hospital Queen zalecha Martapura, it is advisable to increase the cleanliness of individuals and the use of personal protective equipment to reduce the incidence of nosocomial infections in the scope of the hospital. Keywords: MRSA; VRSA; Paramedic Abstrak: Galur Staphylococcus aureus yang diisolasi dari rumah sakit umumnya telah resisten terhadap berbagai antimikroba, Galur Staphylococcus aureus yang resisten terhadap vankomisin masih jarang dilaporkan. Galur Methicillin-resistant Staphylococcus aureus (MRSA) merupakan penyebab utama infeksi nosokomial yang bersifat multiresisten terhadap antibiotik. Penelitian ini bertujuan untuk mengetahui adanya bakteri Methicillin-resistant Staphylococcus aureus (MRSA) dan Vancomycin resistant Staphylococcus aureus (VRSA) pada paramedis di ruang perawatan bedah dan perawatan ICU RSUD Ratu Zalecha Martapura. Penelitian ini menggunakan metode survey deskriptif. Populasi pada penelitian ini adalah perawat yang bekerja di ruang perawatan bedah dan ruang ICU yang berjumlah 38 orang. Tehnik sampling secara accidental sampling dengan jumlah sampel 27 orang. Hasil penelitian diketahui dari 27 sampel yang positif Staphylococcus aureus 14 orang, hasil uji sensitivitas terdapat 7 sampel resisten terhadap cefoxitin (MRSA 26%), 4 sampel resisten terhadap oxacilin dan 7 sampel resisten terhadap vancomycin (VRSA 26%). Disimpulkan terdapat MRSA dan VRSA di Rumah sakit Ratu zalecha Martapura, disarankan untuk meningkatkan kebersihan individu dan penggunaan alat pelindung diri untuk mengurangi kejadian infeksi nosokomial di lingkup rumah sakit. Kata Kunci : MRSA; VRSA ; Paramedis