The Prevalence and Antimicrobial Susceptibility Pattern of Gram-Positive Pathogens: Three-Year Study at a Tertiary Care Hospital in Mumbai, India

Abstract

Introduction The growing resistance pattern of the gram-positive pathogens along with a steady increase in minimum inhibitory concentration of the currently available antibiotics have led to an increase in morbidity and mortality rates in India. This study aims to access the shifting antibiotic susceptibility paradigm of the gram-positive pathogens in various infections at a tertiary care center. Methods This is a 3-year retrospective observational study which was performed from January 2016 to December 2018 at a tertiary care hospital in Mumbai. All clinically significant gram-positive cocci isolated from a variety of clinical specimens were studied for their prevalence and antimicrobial susceptibility. Results Out of 4,428 gram-positive isolates, Staphylococcus aureus (35.3%) was the commonly encountered pathogen, followed by Enterococcus spp. (32.1%) and coagulase-negative Staphylococcus (CoNS) (25.7%). S. aureus was majorly isolated from skin and soft tissue infections (60.3%), followed by patients with respiratory tract infections (18.2%) and blood stream infections (13%). Among S. aureus, particularly methicillin-resistant S.aureus (MRSA), prevalence increased from 29.5% in 2016 to 35.1% in 2018, with an overall prevalence of 33.6%. All S. aureus isolates were 100% sensitive toward vancomycin, linezolid, tigecycline, and teicoplanin. However, the CoNS isolates showed a higher resistance rate with reduced susceptibility toward linezolid and teicoplanin. High prevalence of resistance was observed across gram-positive isolates with commonly used antibiotics such as ciprofloxacin, levofloxacin, and erythromycin. While the prevalence of linezolid-resistant enterococcus (LRE) was 3.6%, vancomycin (VRE) and teicoplanin resistance among the enterococcus species was as high as 7.7% and 7.5%, respectively. Conclusion Rising methicillin resistance among the Staphylococcal species (MRSA and MR-CoNS) along with reduced susceptibility toward currently available anti-MRSA agents is a matter of serious concern as it limits the therapeutic options for treating multidrug resistant (MDR) gram-positive infections.

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

“…In support to the above findings, Rajaduraipandi et al also found 31.1% MRSA strains in their investigation, [19]. Various studies from different regions of India including Mumbai, Haryana and Greater Noida, presented the prevalence of MRSA similar to the present study [20][21][22]. More than 50% prevalence of MRSA was observed in MRSA from different states of India.…”

A High Level of Antimicrobial Resistance in Gram-Positive Cocci Isolates from Different Clinical Samples Among Patients Referred to Arsho Advanced Medical Laboratory, Addis Ababa, Ethiopia

“…Then, suspension for inoculation of AST GP 71 card which was used for drug susceptibility test was done by transferring 280μL of culture suspension from the first suspension into another 3mL of sterile saline solution (0.45% to 0.50% NaCl, pH 6.8-7.2) to obtain the final turbidity of 8 × 10 6 CFU/mL. AST-GP71 card which was used for drug susceptibility tests of Gram-positive bacteria contains; penicillin (0.125, 0.25, 1, 2, 8, 64), ciprofloxacin (1,2,4), clindamycin (0.5, 1, 2), daptomycin (0.5, 1, 2, 4, 16), erythromycin (0.25, 0.5, 2), gentamicin (8,16,64), levofloxacin (0.25, 2, 8), linezolid (0.5, 2, 8), minocycline (0.12, 0.5, 2), moxifloxacin (0.25, 2, 8), nitrofurantoin (16,32,64), oxacillin (0.5, 1, 2), quinupristin/dalfopristin (0.25, 0.5, 2), rifampicin (0.25, 0.5, 2), tetracycline (0.5, 1, 2), tigecycline (0.25, 0.5, 1), trimethoprim/sulfamethoxazole (2/38, 8/152, 16/304), and vancomycin (1,2,4,8,16). The concentration values are expressed in µg/mL, which were obtained from the package insert information provided in the kit of AST-GP71 card.…”

“… 1 Due to their quick potential to develop resistance to the currently prescribed medicines, gram-positive bacteria are the main cause of healthcare-associated and community-acquired infections. 2 For both hospital and community-associated infections, Gram-positive bacteria, especially Gram-positive cocci (GPC) such staphylococci, streptococci, and enterococci, are among the most frequent pathogens. 3–6 …”

“…1 Due to their quick potential to develop resistance to the currently prescribed medicines, gram-positive bacteria are the main cause of healthcare-associated and community-acquired infections. 2 For both hospital and community-associated infections, Gram-positive bacteria, especially Gram-positive cocci (GPC) such staphylococci, streptococci, and enterococci, are among the most frequent pathogens. [3][4][5][6] Staphylococcus aureus (causes wound infections) and coagulase-negative staphylococci (CoNS) (causes nosocomial bloodstream infections), and Enterococci are the most commonly isolated Gram-positive cocci from nosocomial infections.…”

“…3 Prolonged usage of the available effective antibiotics against GPC coupled with their decreasing susceptibility rates have led to the emergence and spread of multidrug-resistant pathogens. 2 Gram-positive cocci bacteria have shown the ability to acquire and express numerous antimicrobial resistance mechanisms which lead to a multidrug-resistant (MDR) phenotype that further complicates treatment efforts in addition to the innate virulence exhibited by bacteria like S. aureus and S. pneumoniae. 6 Infections caused by MDR pathogens are an increasing problem and remain one of the main challenges in the treatment of infectious diseases.…”