Detection of Inducible Resistance to Clindamycin among Methicillin Resistant and Sensitive strains of Staphylococcus aureus from India

The resistance to MLSB antibiotics, i.e. Macrolide-Lincosamide-Streptogramin B (MLSB), is an increasing problem among Methicillin-resistant Staphylococci. The resistance to macrolides can be by efflux mechanism or via inducible or constitutive resistance. Unfortunately, routine clindamycin susceptibility testing fails to detect the inducible resistance, which commonly results in treatment failure and necessitates incorporating a simple D-test to detect such resistance. A retrospective observational study was performed on S. aureus isolates from patients. The strains were subjected to antibiotic susceptibility testing followed by detection of mecA gene by a polymerase chain reaction and, the ‘D-test’ was performed to know the inducible resistance to clindamycin. A total of 235 isolates were identified as S. aureus. Antibiotic susceptibility test indicated 190 MRSA and 45 are sensitive to MLSB (MS). Inducible clindamycin resistance was found among 48 (20.4%) isolates and constitutive resistance in 104 (44.2%). MRSA strains had higher inducible and constitutive resistance than MSSA strains (22.1%, 51.6% and 13.3%, 13.3%, respectively). Clindamycin is a commonly used antibiotic in patients with MRSA infections to spare higher-end anti-MRSA antibiotics like linezolid and vancomycin. To detect inducible clindamycin to avoid treatment failures; the study showed the importance of incorporating the D-test in routine testing.

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Phenotypic study of Macrolide-Lincosamide-Streptogramin B Resistance in Staphylococcus aureus and their relationship with Methicillin-Resistant Staphylococcus aureus (MRSA) at Tertiary Care in Eastern Nepal

Journal of Nobel Medical College ◽

10.3126/jonmc.v5i1.15745 ◽

2016 ◽

Vol 5 (1) ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Ganesh Kumar Singh ◽

Bigu Kumar Chaudhari ◽

Kamal Prasad Parajuli

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Tertiary Care ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Constitutive Resistance ◽

Antibiotic Susceptibility Test

Background Resistance to antimicrobial agents is prevalent among Staphylococci. This has led to wide uses of macrolide-lincosamide-streptogramin B (MLSB) antibiotics to Staphylococcus aureus (S. aureus) infections. MLSB though chemically distinct, have similar target site and mode of action. The multiple mechanisms are responsible for resistance to MLSB antibiotics which can lead to clinical failure. The aim of the study was to investigate the frequency of inducible and constitutive clindamycin resistance among clinical isolates of S. aureus and their relationship with Methicillin-resistant Staphylococcus aureus (MRSA).Material & Methods A total of 336 unique Staphylococcus aureus isolates from different clinical samples obtained from patients were studied. Antibiotic susceptibility test was performed by Kirby- Bauer disc diffusion method. “D test” was performed to detect inducible clindamycin resistance as per CLSI guidelines. MRSA was detected using Cefoxitin (30μg) and results were interpreted according to CLSI criteria.Results Inducible clindamycin resistance was seen in 45 (13.39%), constitutive clindamycin resistance was seen among 58 (17.26%) while MS phenotype was observed among 38(11.30%) of isolates. Inducible resistance as well as constitutive resistance was higher among MRSA as compared to MSSA (21.11%, 4.48% and 21.11%, 12.82%respectively).Conclusion The Successful use of clindamycin for the treatment of infection caused by S. aureus can be predicted based on the result of simple and inexpensive D test.Journal of Nobel Medical CollegeVolume 5, Number 1, Issue 8, January-July 2016, 1-5

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Characteristics of Erythromycin Resistance in Methicillin-Resistant Staphylococcus aureus Isolated From Raw Milk

International Journal of Enteric Pathogens ◽

10.15171/ijep.2019.25 ◽

2019 ◽

Vol 7 (4) ◽

pp. 121-125

Author(s):

Fatemeh Mahdavi ◽

Fatemeh Zaboli ◽

Rahem Khoshbakht

Keyword(s):

Staphylococcus Aureus ◽

Resistance Genes ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Meca Gene ◽

Raw Milk ◽

Erythromycin Resistance ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Mrsa Strains

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the most important multidrug resistant microorganisms that threaten human health. Objective: The present study was conducted to evaluate genotypic and phenotypic characteristics of erythromycin resistance among MRSA isolates recovered from raw milk in Iran. Materials and Methods: A total of 50 MRSA isolates were recovered from raw milk. Tests for erythromycin and clindamycin susceptibility and inducible clindamycin resistance were done. In addition, the presence of the methicillin resistance determinant (mecA), erythromycin resistance genes (ermA, ermB, ermC and msrA) and an important virulence gene (Panton– Valentine leukocidin) were investigated using polymerase chain reaction (PCR) method. Results: Forty-eight percent (24/50) and 46% (23/50) of the isolates were resistant to erythromycin and clindamycin, respectively. Seven (14%) isolates showed inducible clindamycin resistance phenotype. The mecA gene was detected in 88% (44/50) of MRSA isolates. The incidence of the ermA, ermB, ermC and msrA genes was 14%, 64%, 12%, and 26%, respectively and the PVL gene was present in 18% (9/50) of MRSA isolates. Conclusion: According to the results of the study, the incidence of erythromycin resistance genes and inducible clindamycin-resistant MRSA strains was high in raw milk samples in Iran.

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Antibiotic Susceptibility, Biofilm Production, and Detection of mecA Gene among Staphylococcus aureus Isolates from Different Clinical Specimens

Diseases ◽

10.3390/diseases9040080 ◽

2021 ◽

Vol 9 (4) ◽

pp. 80

Author(s):

Upama Gaire ◽

Upendra Thapa Shrestha ◽

Sanjib Adhikari ◽

Nabaraj Adhikari ◽

Anup Bastola ◽

...

Keyword(s):

Multidrug Resistance ◽

Antibiotic Susceptibility ◽

Methicillin Resistance ◽

Meca Gene ◽

Conventional Polymerase Chain Reaction ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Clinical Specimens ◽

Antibiotic Susceptibility Test

The increasing incidence of methicillin-resistant and biofilm-forming S. aureus isolates in hospital settings is a gruesome concern today. The main objectives of this study were to determine the burden of S. aureus in clinical samples, assess their antibiotic susceptibility pattern and detect biofilm formation and mecA gene in them. A total of 1968 different clinical specimens were processed to isolate S. aureus following standard microbiological procedures. Antibiotic susceptibility test of the isolates was performed by Kirby–Bauer disc-diffusion method following CLSI guidelines. Biofilm was detected through tissue culture plate method. Methicillin-resistant S. aureus (MRSA) isolates were screened using cefoxitin (30 µg) discs and mecA gene was amplified by conventional polymerase chain reaction (PCR). Of 177 bacterial growth, the prevalence of S. aureus was 15.3% (n = 27). MRSA were 55.6% (15/27) and 44% (12/27) exhibited multidrug resistance (MDR). There was no significant association between methicillin resistance and MDR (p > 0.05). Both MRSA and MSSA were least sensitive to penicillin (100%, 75%) followed by erythromycin (86.6%, 66.6%). Most of the MRSA (93.4%) were susceptible to tetracycline. All S. aureus isolates were biofilm producers—19 (70%) were weak and only one (4%) was a strong biofilm producer. The strong biofilm-producing MSSA was resistant to most of the antibiotics except cefoxitin and clindamycin. None of the MSSA possessed mecA gene while 8 (53.3%) MRSA had it. More than half of S. aureus isolated were MRSA. High incidence of multidrug resistance along with capacity to form biofilm among clinical isolates of S. aureus is a matter of apprehension and prompt adoption of biosafety measures is suggested to curb their dissemination in the hospital environments.

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Inducible Clindamycin Resistance and Molecular Epidemiologic Trends of Pediatric Community-Acquired Methicillin-Resistant Staphylococcus aureus in Dallas, Texas

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.6.2283-2288.2005 ◽

2005 ◽

Vol 49 (6) ◽

pp. 2283-2288 ◽

Cited By ~ 76

Author(s):

Susana Chavez-Bueno ◽

Bülent Bozdogan ◽

Kathy Katz ◽

Karen L. Bowlware ◽

Nancy Cushion ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Resistance Mechanisms ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Inducible Resistance ◽

Mrsa Infection ◽

Resistant Strains ◽

Mrsa Strains ◽

Disk Test

ABSTRACT Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection occurs commonly in children. Clindamycin resistance may be inducible or constitutive, and the rates of inducible resistance in CA-MRSA that could produce clindamycin treatment failures vary worldwide. The double-disk test was performed in 197 erythromycin-resistant and clindamycin-susceptible CA-MRSA strains from children in Dallas, Texas, from 1999 to 2002 to determine inducible clindamycin resistance. Resistance mechanisms were studied by PCR; epidemiologic trends were studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Inducible resistance was demonstrated in 28 (93% ±6%) of 30 tested isolates in 1999, 21 (64%, ±11%) of 33 in 2000, 12 (23% ±7%) of 52 in 2001, and 6 (7% ±3%) of 82 in 2002. All noninducible strains had the msr(A) gene. Among inducible resistant strains, 31 had erm(B), 24 had erm(C), and 12 had erm(A) genes. Two distinct pulsed types were the most prevalent; one of them was the most common pulsed type in 1999, whereas in 2002 a different pulsed type was prevalent. MLST analyses determined that ST-8 was the most common type, with 76% ±5% found in 2002. All but one of these clindamycin-susceptible, erythromycin-resistant ST-8 strains showed no induction of clindamycin resistance. We conclude that, among erythromycin-resistant, clindamycin-susceptible CA-MRSA strains isolated from children in Dallas, inducible methylase resistance became less common from 1999 to 2002 (P < 0.001). The phenotype of strains was associated with their sequence type. Our results demonstrate a clonal shift in CA-MRSA in Dallas children from 1999 to 2002.

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

Tropical Medicine and Health ◽

10.1186/s41182-021-00392-2 ◽

2021 ◽

Vol 49 (1) ◽

Author(s):

Devi Thapa ◽

Susil Pyakurel ◽

Sabita Thapa ◽

Suresh Lamsal ◽

Mahesh Chaudhari ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Methicillin Resistance ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital ◽

Antibiotic Susceptibility Testing ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance

Abstract 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.

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Microarray Technology for the Detection of Antimicrobial Resistance Genes Present in Hospital and Community Acquired Methicillin Resistant S.aureus Strains

Revista de Chimie ◽

10.37358/rc.17.11.5925 ◽

2017 ◽

Vol 68 (11) ◽

pp. 2546-2550

Author(s):

Monica Licker ◽

Andrei Anghel ◽

Roxana Moldovan ◽

Elena Hogea ◽

Delia Muntean ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Dna Microarray ◽

Bacterial Resistance ◽

Meca Gene ◽

Modern Medicine ◽

Microarray Technology ◽

Methicillin Resistant ◽

Antimicrobial Sensitivity ◽

Antimicrobial Resistance Genes ◽

Mrsa Strains

Antimicrobial resistance (AMR) represents a real burden for the modern medicine. One of the most frecvently isolated hospital acquired (HA) pathogens wordlwide, is Methicillin resistant Staphylococcus aureus (MRSA). Recently not only HA, but also community-acquired MRSA (CA-MRSA) infections have been reported. A prospective study was performed between February 2009 and October 2010, with the aim to investigate bacterial resistance of CA-MRSA and HA-MRSA. DNA microarray technology has been used for the detection of 4 AMR genes for the studied MRSA strains. A number of 218 HA- S.aureus strains have been isolated, from which 89 (40. 82%) were MRSA. In the community, 1.553 S.aureus strains were isolated, out of which, 356 (22. 92%) were MRSA. From these, a number of 17 HA and 12 CA �MRSA strains have been analyzed by DNA microarray technology. From 100% phenotypically described HA- MRSA, we identified mecA gene in 10 strains (58. 83%). Other 6 strains (35. 29%) have been erm(A) positive and 4 (23. 53%) - tet(O) positive. 83. 33% (10 strains) from the CA strains had mecA gene, only one (8. 33%) was erm(A) positive and 4 (33. 33%) were erm(C) positive. DNA microarray is a method allowing the concomitant scan of multiple genes and can be done within a few hours. That type of rapid and reliable methods for antimicrobial sensitivity tests are important to start an appropriate therapy.

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Methicillin-Resistant Staphylococcus aureus Recovered from Healthcare- and Community-Associated Infections in Egypt

International Journal of Bacteriology ◽

10.1155/2016/5751785 ◽

2016 ◽

Vol 2016 ◽

pp. 1-5 ◽

Cited By ~ 17

Author(s):

Mohamed Abdel-Maksoud ◽

Mona El-Shokry ◽

Ghada Ismail ◽

Soad Hafez ◽

Amani El-Kholy ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Infection Control ◽

Continuous Monitoring ◽

Inhibitory Concentration ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

The Past ◽

Mrsa Strains ◽

Healthcare Associated ◽

Over Time

Background. Methicillin-resistant Staphylococcus aureus (MRSA) has created significant epidemiological, infection-control, and therapeutic management challenges during the past three decades. Aim. To analyze the pattern of resistance of healthcare- and community-associated MRSA in Egypt and the trend of resistance of HA-MRSA over time (2005–2013). Methods. MRSA isolates were recovered from healthcare-associated (HA) and community-associated (CA) Staphylococcus aureus (S. aureus) infections. They were tested against 11 antimicrobial discs and the minimal inhibitory concentration (MIC) of vancomycin was determined. Inducible clindamycin resistance (iMLSB) was also screened using D-test. Findings. Of 631 S. aureus, MRSA was identified in 343 (76.6%) and 21 (11.5%) of HA and CA S. aureus isolates, respectively. The proportion of HA-MRSA increased significantly from 48.6% in 2005 to 86.8% in 2013 (p value < 0.001). Multidrug resistance (MDR) was observed in 85.8% of HA-MRSA and 48.6% of CA-MRSA. Vancomycin intermediate resistant S. aureus (VISA) was detected in 1.2% of HA-MRSA and none was detected in CA-MRSA. Among HA-MRSA strains, 5.3% showed iMLSB compared to 9.5% among CA-MRSA. Conclusion. The upsurge of the prevalence rates of HA-MRSA over time is alarming and urges for an effective infection control strategy and continuous monitoring of antimicrobial use.

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Characteristics of Staphylococcus Xylosus Isolated from Subclinical Mastitis in Cows

Annals of Animal Science ◽

10.2478/aoas-2014-0053 ◽

2014 ◽

Vol 14 (4) ◽

pp. 859-867 ◽

Cited By ~ 3

Author(s):

Mariola Bochniarz ◽

Władysław Wawron ◽

Marek Szczubiał ◽

Piotr Brodzki ◽

Tomasz Piech ◽

...

Keyword(s):

Virulence Factors ◽

Antibiotic Susceptibility ◽

Somatic Cells ◽

Meca Gene ◽

Subclinical Mastitis ◽

Methicillin Resistant ◽

Milk Samples ◽

Staphylococcus Xylosus ◽

Resistant Group ◽

Cephalosporin Antibiotics

Abstract The aim of the present study was to determine virulence factors and antibiotic susceptibility of Staphylococcus xylosus isolated from subclinical mastitis in cows. The material consisted of 42 isolates of S. xylosus obtained from 276 samples of milk collected from cows with subclinical mastitis. The isolates were obtained from the udder secretions of 33 cows from farms in the Lublin region (Poland). S. xylosus was found in 15.2% of tested milk samples. The study did not reveal any macroscopic changes in the milk or symptoms in the cow’s body. The number of somatic cells in milk samples ranged from 245,000 to 416,000/ml of milk (on average 268,000/ml of milk). The ability to produce slime was observed in 42.9% of S. xylosus isolates. None of the tested isolates demonstrated the ability to produce protease or cause haemolysis. Five isolates of S. xylosus (11.9%) were classified to the methicillin-resistant group. The mecA gene was not found in any of these isolates. The enzyme β-lactamase was detected in 28.6% of S. xylosus isolates. The highest efficacy against S. xylosus was demonstrated for cephalosporin antibiotics: cefacetrile and cefoperazone (80.1% and 76.2% of susceptible isolates of S. xylosus, respectively). A significant quantity of isolates was resistant to streptomycin, linkomycin, penicillin and neomycin (approximately 10% of susceptible isolates of S. xylosus).

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Potensi Ekstrak Atuna racemosa sebagai Anti - Methicillin Resistant Staphylococcus aureus (MRSA)

Jurnal Sain Veteriner ◽

10.22146/jsv.34700 ◽

2017 ◽

Vol 35 (2) ◽

pp. 260

Author(s):

Siti Isrina Oktavia Salasia ◽

Novra Arya Sandi ◽

Fajar Budi Lestari ◽

Verda Farida ◽

Nurbani Aziz

Keyword(s):

Staphylococcus Aureus ◽

Meca Gene ◽

New Drugs ◽

Diffusion Test ◽

Methicillin Resistant ◽

Causative Agents ◽

Mrsa Infection ◽

Polymerase Chain ◽

Mrsa Strains ◽

Multiple Antibiotics

Staphylococcus aureus is one of the major causative agents of mastitis in animals and a variety of human diseases such as septicemia, endocarditis, arthritis dan osteomyelitis. Infection of Methicillin-resistant S. aureus (MRSA) has been widely reported and these strains are usually resistant to multiple antibiotics. The purpose of this study was to evaluate the potential of Atuna racemosa, as an alternative herbal medicine against MRSA infection. The MRSA strains were isolated from human and confirmed based on their resistant to various antibiotics and analyzing of the mecA gene by polymerase chain reaction (PCR). Atuna racemosa originated from Ambon, Maluku, Indonesia, were extracted using 70% ethanol. The activities of the Atuna racemosa extract against MRSA were performed by diffusion disc agar and dilussion agar tests. The results showed that Atuna racemosa extract has the barrier effect of MRSA growth at a concentration of 5% in the diffusion test and at a concentration of 7% in the dilution test. Atuna racemosa could be used as an alternative new drugs with dose of 0.07 g/ml (7%) against MRSA which is multi-resistant to many antibiotics.

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Peculiarities of antibiotic resistance of Staphylococcus aureus strains isolated from nosocomial infections

Kazan medical journal ◽

10.17816/kmj2020-325 ◽

2020 ◽

Vol 101 (3) ◽

pp. 325-329

Author(s):

S A Atakishizade

Keyword(s):

Antibiotic Resistance ◽

Nosocomial Infections ◽

Methicillin Resistance ◽

Surgical Site Infections ◽

Diffusion Method ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Significant Difference ◽

Microbiological Testing ◽

Mrsa Strains

Aim. To study of the antibiotic resistance of S. aureus strains isolated from nosocomial infections (pneumonia, surgical site infections and sepsis) in a multidisciplinary surgical clinic. Methods. Microbiological testing of sputum in 41 patients with pneumonia, of samples (wound, abscess, drainage) obtained from 40 patients with surgical site infections (SSI) and of blood from 46 patients with signs of sepsis was performed. The obtaining cultures were identified by conventional methods (including morphological, cultural, biochemical features, etc.). Disc diffusion method was used to detect methicillin-resistant S. aureus (MRSA) strains. Inducible clindamycin resistance (ICR) of S. aureus strains was determined by double disk approximation test (D-test). Results. Methicillin-resistant S. aureus was found in 14.3% (2 of 14) of the patients with surgical site infections, in the sputum 27.3% (3 of 11) of the patients with pneumonia, and in the blood 50.0% (7 of 14) of the patients with sepsis (p 0.05). The rate of inducible clindamycin resistance of isolated S. aureus strains in patients with surgical site infections (2 of 14 cases, 14.3%) and with pneumonia (2 of 11 cases, 18.2%) did not statistically significant difference with the rate of methicillin resistance (p 0.05). However the rate was significantly lower septic infections 7.1% and 50.0% respectively (p=0.0328). Conclusion. Among S. aureus strains isolated from nosocomial infections, the rate of methicillin-resistant S. aureus had not depended on the type of nosocomial infection; the rate of inducible clindamycin resistance in septic infections was lower than resistance to methicillin.

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