SURVEY OF STAPHYLOCOCCUS ISOLATES AMONG HOSPITAL PERSONNEL, ENVIRONMENT AND THEIR ANTIBIOGRAM WITH SPECIAL EMPHASIS ON METHICILLIN RESISTANCE

Isolation, characterisation and antibiotic susceptibility of staphylococcal isolates with special reference to methicillin-resistant Staphylococcus aureus from the anterior nares of healthcare workers in A tertiary healthcare centre

Background: Staphylococcus aureus (S. aureus) and its resistant form methicillinresistant S. aureus (MRSA) is one of the most common nosocomial pathogens causing a wide range of infections in humans. The anterior nares are the main ecological niche for S. aureus. Nasal carriage of S. aureus acts as an important reservoir of infection among the colonised healthcare workers and they transmit the infection to the community. The aim of the present study was to estimate the nasal colonisation of S. aureus (with special reference to MRSA) in healthcare workers (doctors and nursing staff) and its antibiotic susceptibility pattern. Methods: A descriptive study was planned in the Department of Microbiology, JLN Medical College, Ajmer (Rajasthan, India) after due approval from the institutional ethics committee. A total of 170 healthcare workers of either sex aged between 18 to 60 years were screened for S. aureus. Identification was done using standard microbiological techniques, by studying their morphology, colony and biochemical characteristics. MRSA was detected by cefoxitin disc diffusion test, oxacillin disc diffusion test, minimum inhibitory concentration (MIC) of oxacillin by E-test and oxacillin screen agar test. The observations were described in proportions and Chisquared test was used to find independence. Statistical significance was considered at 5 %. Results: Among 170 samples, 159 (93.53 %) samples (50 doctors and 109 nursing staff) had staphylococci colonisation. Among these 159 isolates, 34 (21.38 %) were S. aureus. Further, 8 (5.03 %) S. aureus isolates were resistant to both cefoxitin and oxacillin and had oxacillin MIC values ≥ 4 µg/mL and were considered MRSA. All the MRSA were detected in the nursing staff (males: 5.50 %, females: 1.83 %). All S. aureus and MRSA isolates were found sensitive to linezolid, vancomycin and mupirocin (minimum inhibitory concentration ≤ 4 µg/mL). Conclusion: Screening and treatment of healthcare workers colonised with MRSA should be an important component of hospital infection control policy. These measures will prevent spread of infection to patients and the community and thereby reduce the morbidity, mortality and healthcare costs associated with nosocomial infections.

Methicillin-resistant Staphylococcus aureus in Intensive Care Unit Setting of India: A Review of Clinical Burden, Patterns of Prevalence, Preventive Measures, and Future Strategies

Aim

The aim of this review article is not only to analyze the clinical burden of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care unit (ICU) setting of India, along with the patterns of prevalence and its prevention measures, but also to focus on the new anti-MRSA research molecules which are in late stage of clinical development.

Background

Methicillin resistance is reported to be present in 13–47% of Staphylococcus aureus infections in India. Therapeutic options to combat MRSA are becoming less, because of emerging resistance to multiple classes of antibiotics. Intensive care units are the harbinger of multidrug-resistant organisms including MRSA and are responsible for its spread within the hospital. The emergence of MRSA in ICUs is associated with poor clinical outcomes, high morbidity, mortality, and escalating treatment costs. There is an urgency to bolster the antibiotic pipeline targeting MRSA. The research efforts for antibiotic development need to match with the pace of emergence of resistance, and new antibiotics are needed to control the impending threat of untreatable MRSA infections.

Review results

Fortunately, several potential antibiotic agents are in the pipeline and the future of MRSA management appears reassuring.

Clinical significance

The authors believe that this knowledge may help form the basis for strategic allocation of current healthcare resources and the future needs.

How to cite this article

Mehta Y, Hegde A, Pande R, Zirpe KG, Gupta V, Ahdal J, et al. Methicillin-resistant Staphylococcus aureus in Intensive Care Unit Setting of India: A Review of Clinical Burden, Patterns of Prevalence, Preventive Measures, and Future Strategies. Indian J Crit Care Med 2020;24(1):55–62.

Community-acquired meticillin-resistant Staphylococcus aureus in Palestine

Community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) is becoming an important public-health problem. This study attempted to investigate S. aureus and MRSA colonization in nasal swabs obtained from 843 patients without a history of hospitalization at the time of hospital admission and from 72 health-care workers chosen for comparison. Of the patients, S. aureus was detected in 218/843 (25.9%) and MRSA in 17/843 (2.0%). Of the health-care workers, S. aureus was detected in 15/72 (20.8%) and MRSA in 10/72 (13.9%). The majority of the 27 MRSA isolates exhibited a sensitivity pattern expected for CA-MRSA. Multilocus restriction fragment typing resolved the isolates into eight restriction fragment types. The predominant restriction fragment types were AAACCAA and AAAAAAA, accounting for 51.9% (14/27) of the MRSA isolates and included CC5 and CC1 groups, respectively. This study thus demonstrated the transmission of CA-MRSA strain types into a health-care setting, emphasizing the need for implementation of a revised set of control measures in both hospital and community settings.

Diversity of staphylococcal cassette chromosome mec structures in methicillin-resistant Staphylococcus epidermidis and Staphylococcus haemolyticus strains among outpatients from four countries

In staphylococci, methicillin (meticillin) resistance (MR) is mediated by the acquisition of the mecA gene, which is carried on the size and composition variable staphylococcal cassette chromosome mec (SCCmec). MR has been extensively studied in Staphylococcus aureus, but little is known about MR coagulase-negative staphylococci (MR-CoNS). Here, we describe the diversity of SCCmec structures in MR-CoNS from outpatients living in countries with contrasting environments: Algeria, Mali, Moldova, and Cambodia. Their MR-CoNS nasal carriage rates were 29, 17, 11, and 31%, respectively. Ninety-six MR-CoNS strains, comprising 75 (78%) Staphylococcus epidermidis strains, 19 (20%) Staphylococcus haemolyticus strains, 1 (1%) Staphylococcus hominis strain, and 1 (1%) Staphylococcus cohnii strain, were analyzed. Eighteen different SCCmec types were observed, with 28 identified as type IV (29%), 25 as type V (26%), and 1 as type III (1%). Fifteen strains (44%) were untypeable for their SCCmec. Thirty-four percent of MR-CoNS strains contained multiple ccr copies. Type IV and V SCCmec were preferentially associated with S. epidermidis and S. haemolyticus, respectively. MR-CoNS constitute a widespread and highly diversified MR reservoir in the community.