Inducible Clindamycin Resistance among Staphylococci Isolated from Burn Patients

Inducible Clindamycin-Resistant Staphylococcus aureus Strains in Africa: A Systematic Review

Introduction

Excessive use of clindamycin enhances the acquisition of inducible clindamycin-resistant S. aureus strains, which is a significant health problem in Africa. The main objective of this review study was to determine the prevalence of inducible clindamycin resistance and related genes among S. aureus isolates in Africa.

Methods

A qualitative systematic review was conducted on inducible clindamycin resistance among S. aureus isolates in Africa using electronic databases such as Google Scholar and PubMed. Articles published in English before 2021 were selected, and relevant data were extracted, collected, and analyzed.

Results

In our search, 22 articles met the eligibility criteria for this review study. Of 3064 total S. aureus isolates, 605 had iMLSB phenotype. The overall prevalence of inducible clindamycin resistance in S. aureus isolates was 19.8% with a range of 2.9% to 44.0%. A high number of iMLSB phenotypes were observed in MRSA isolates (3.6–77.8%) than MSSA (0–58.8%). The overall prevalence of the iMLSB phenotype in MRSA strains was 26.8% (279/1041). The maximum peak prevalence of inducible clindamycin resistance among S. aureus isolates recorded in the continent was 44.0% in Egypt, followed by 35.8% in Libya and 33.3% in Uganda in 2017, 2007, and 2013, respectively. The highest prevalence of iMLSB phenotype in MRSA strains was reported in Egypt, 77.8%, followed by Nigeria, 75.0%, and Libya, 66.2%. Among the recovered drug-resistance genes, ermA, ermC, and msrA genes were commonly detected in Egypt with 67.9%, 70.0%, and 70.0% prevalence, respectively.

Conclusion

This review highlights a higher inducible resistance of S. aureus, including MRSA strains to clindamycin in the continent. Regular screening of these strains, wise use of clindamycin, and molecular detection and genotyping of resistant genes are urgent.

Phenotypic and molecular characterization of resistance to macrolides, lincosamides and type B streptogramin of clinical isolates of Staphylococcus spp. of a university hospital in Recife, Pernambuco, Brazil

Introduction

There is a mechanism of macrolide resistance in Staphylococcus spp. which also affects the lincosamides and type B streptogramins characterizing the so-called MLS_B resistance, whose expression can be constitutive (cMLS_B) or inducible (iMLS_B) and is encoded mainly by ermA and ermC genes. The cMLS_B resistance is easily detected by susceptibility testing used in the laboratory routine, but iMLS_B resistance is not. Therapy with clindamycin in cases of infection with isolated iMLS_B resistance may fail.

Objective

To characterize the phenotypic (occurrence of cMLS_B and iMLS_B phenotypes) and molecular (occurrence of ermA and ermC genes) profiles of MLS_B resistance of clinical isolates of susceptible and methicillin-resistant Staphylococcus aureus and CNS (coagulase-negative Staphylococcus) from patients of a university hospital, in Pernambuco.

Methods

The antimicrobial susceptibility of 103 isolates was determined by the disk diffusion technique in Mueller–Hinton agar followed by oxacillin screening. The iMLS_B phenotype was detected by D test. Isolates with cMLS_B and iMLS_B phenotypes were subjected to polymerase chain reaction (PCR) for the detection of ermA and ermC genes.

Results

The cMLS_B and iMLS_B phenotypes were respectively identified in 39 (37.9%) and five (4.9%) isolates. The iMLS_B phenotype was found only in four (10.8%) methicillin-susceptible S. aureus and one (4.5%) methicillin-resistant S. aureus. In the 44 isolates subjected to PCR, four (9.1%) only ermA gene was detected, a lower frequency when compared to only ermC 17 (38.6%) gene and to one (2.3%) isolate presenting both genes.

Conclusion

In the Staphylococcus spp. analyzed, the ermC gene was found more often than the ermA, although the iMLS_B phenotype had been less frequent than the cMLS_B. It was important to perform the D test for its detection to guide therapeutic approaches.

The Rate of Inducible MLSB Resistance in the Methicillin-Resistant Staphylococci Isolated From Clinical Samples

BACKGROUND

Staphylococci are one of the most common pathogens in nasocomial and community-acquired infections. Methicillin-resistant staphylococci are known to be resistant against all beta-lactam antibiotics. Therefore, non-beta-lactam antibiotics such as macrolide and lincosamides can be used. Resistance to those antibiotics may lead to therapeutic failure. The purpose of the present study was to determine the prevalence of macrolide-lincosamide-streptogramin B (MLSB ) resistance by using D-test in staphylococcal isolates from various clinical samples.

METHODS

Seventy-one methicillin-resistant Staphylococcus isolates (six S. aureus, 65 coagulase negative staphylococci) were included in this study. Staphylococci were identified with conventional methods. According to Clinical Laboratory Standards Institute (CLSI) criteria, susceptibility testing was performed by Kirby-Bauer disk diffusion method.

RESULTS

One of six (16.6%) methicillin-resistant S. aureus isolates and 19 of 65 (29.2%) methicillin-resistant coagulase-negative staphylococci (MR-CNS) were detected as D-test positive. Twenty of 71 (28.1%) staphylococcal isolates detected as D-test positive. Inducible clindamycin resistance was found at a higher rate in MR-CNS.

CONCLUSION

Since the resistant community and hospital acquired staphylococcal infections have become a therapeutic problem, it is very important to detect MLSB resistance routinely in microbiology laboratories. D-test is a cheap and reliable diagnostic method that can be performed in every laboratory.

A report on infection dynamics of inducible clindamycin resistance of Staphylococcus aureus isolated from a teaching hospital in India

OBJECTIVE

To investigate the infection of hospital- and community-acquired "erythromycin-induced clindamycin resistant" strains or D-test positives of clinical isolates of Staphylococcus aureus (S. aureus) (with and without methicillin resistance) in a hospital.

METHODS

Strains of S. aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling.

RESULTS

Of the total 278 isolates, 140 (50.35%) were D-test positives and the rest were D-test negatives. Further, of 140 (100%) positives, 87 (62.14%) and 53 (37.85%) strains were from males and females, respectively. Of 140 (100%) positives, 117 (83.57%) were methicillin resistant S. aureus and 23 (16.42%) were methicillin sensitive S. aureus; of 140 strains, 103 (73.57%) strains from persons with and 37 (26.42%) were without related infections; of 140 strains, 91 (65%) and 49 (35%) were from hospital- and community-acquired samples, respectively. In 140 strains, 118 (84.28%) with comorbidities and 22 (15.71%) without comorbidities cases were recorded; similarly, persons with prior antibiotic uses contributed 108 (77.14%) and without 32 (22.85%) positive strains. These binary data of surveillance were analyzed by a univariate analysis. It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity, corroborated by low P values, P=0.001 1 and 0.002 4, respectively. All isolates (278) were resistant to 17 antibiotics of nine groups, in varying degrees; the minimum of 28% resistance for vancomycin and the maximum of 97% resistance for gentamicin were recorded. Further, of 278 strains, only 42 (15.1%) strains were resistant constitutively to both antibiotics, erythromycin resistant and clindamycin resistant, while 45 (16.2%) strains were constitutively sensitive to both antibiotics (erythromycin sensitive and clindamycin sensitive). Further, of the rest 191 (68.7%) strains were with erythromycin resistant and clindamycin resistant, of which only 140 (50.35%) strains were D-test positives, while the rest 51 (18.34%) strains were D-test negatives.

CONCLUSIONS

In view of high prevalence of D-test positive S. aureus strains, and equally high prevalence of multidrug resistant strains both in community and hospital sectors, undertaking of D-test may be routinely conducted for suppurative infections.

Antibiotic Resistance Profiling of Staphylococcus aureus Isolated from Clinical Specimens in a Tertiary Hospital from 2010 to 2012

MRSA infection can affect a wide array of individuals that may lead to treatment failure. Also, the infection has the potential to spread from one area to another particularly health care facilities or communities eventually causing minor outbreaks. With this premise, the study aimed to describe MRSA infections using the hospital-based data of a tertiary hospital in Bacolod City, Philippines, from 2010 to 2012. Specifically, this study aimed to evaluate the antimicrobial resistance of S. aureus isolated from clinical specimens and to put emphasis on the prevalence of MRSA and Inducible Clindamycin Resistance. A total of 94 cases from 2010 to 2012 were diagnosed to have S. aureus infection using conventional bacteriologic methods. From these cases, 38 (40.6%) were identified as MRSA and 37 (39.4%) were inducible clindamycin resistant. Wounds and abscesses were considered to be the most common specimens with MRSA infections having 71.05% while blood was the least with 5.3%. For drug susceptibility, out of the 94 S. aureus cases, including MRSA, 100% were susceptible to linezolid making it the drug of choice for this study. It was then followed by tetracycline having a mean susceptibility of 95%;, while penicillin G was ineffective with 94 cases having 0% susceptibility.

Antimicrobial resistance in Libya: 1970-2011

Resistance to antimicrobial agents is a major health problem that affects the whole world. Providing information on the past state of antimicrobial resistance in Libya may assist the health authorities in addressing the problem more effectively in the future. Information was obtained mainly from Highwire Press (including PubMed) search for the period 1970-2011 using the terms 'antibiotic resistance in Libya', 'antimicrobial resistance in Libya', 'tuberculosis in Libya', and 'primary and acquired resistance in Libya' in title and abstract. From 1970 to 2011 little data was available on antimicrobial resistance in Libya due to lack of surveillance and few published studies. Available data shows high resistance rates for Salmonella species in the late 1970s and has remained high to the present day. High prevalence rates (54-68%) of methicillin-resistant Staphylococcus aureus (MRSA) were reported in the last decade among S. aureus from patients with burns and surgical wound infections. No reports were found of vancomycin-resistant S. aureus (VRSA) or vancomycin-intermediate-resistant S. aureus (VISA) using standard methods from Libya up to the end of 2011. Reported rates of primary (i.e. new cases) and acquired (i.e. retreatment cases) multidrug-resistant tuberculosis (MDR-TB) from the eastern region of Libya in 1971 were 16.6 and 33.3% and in 1976 were 8.6 and 14.7%, in western regions in 1984-1986 were 11 and 21.5% and in the whole country in 2011 were estimated at 3.4 and 29%, respectively. The problem of antibiotic resistance is very serious in Libya. The health authorities in particular and society in general should address this problem urgently. Establishing monitoring systems based on the routine testing of antimicrobial sensitivity and education of healthcare workers, pharmacists, and the community on the health risks associated with the problem and benefits of prudent use of antimicrobials are some steps that can be taken to tackle the problem in the future.

Inducible clindamycin resistance in Staphylococcus aureus isolates recovered from Mashhad, Iran

BACKGROUND AND OBJECTIVES

Staphylococcus aureus is an important agent in hospital and community-associated infections, causing high morbidity and mortality. Introduction of the new antimicrobial classes for this pathogen has been usually followed by the emergence of resistant strains through multiple mechanisms. For instance, resistance to clindamycin (CLI)can be constitutive or inducible. Inducible clindamycin resistance which may lead to treatment failure can simply be identified by performing D-test. The aim of this study was to determine the prevalence of inducible clindamycin resistance among Staphylococcus aureus isolates by D-test method.

MATERIALS AND METHODS

This was a cross-sectional study conducted on 211 non-duplicated S. aureus isolates in Imam Reza hospital of Mashhad during 2010. Susceptibility to oxacillin, cefoxitin, erythromycin and clindamycin was performed by agar disk diffusion method according to CLSI guidelines and D-shaped clindamycin susceptibility patterns where considered as D-test positive (D(+)).

RESULTS

Of 211 S. aureus isolates,88 (41.7%) were methicillin resistant. It was found that of 88 MRSA isolates, 78 (88.6%) were erythromycin (ERY) resistant and 46 (52.3%) were CLI resistant. ERY and CLI resistance in MSSA strains was 22% and 10.6% respectively. Inducible clindamycin resistance was detected in 18 (20.5%) MRSA isolates. 47(53.4%) of MRSA isolates and 9 (7.3%) of MSSA showed constitutive MLS(B) phenotype.

CONCLUSION

In conclusion, we found a high prevalence of inducible clindamycin resistance phenotype in our region. We recommend that whenever clindamycin is intended to be used for S. aureus infections, D-test should be performed to facilitate the appropriate treatment of patients.