Isolation and Host Range of Lytic Staphylophages on Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Background: Staphylococcus aureus (S. aureus) is a major cause of nosocomial infections in humans and animals. Because of the widespread resistance to antibiotics, microbiologists are trying to find other therapeutic interventions such as phage therapy for bacterial infections. Objectives: The present study aimed to isolate staphylophages with lytic effects on methicillin-resistant S. aureus (MRSA) clinical isolates as a potential alternative agent to antibiotic therapy. Methods: This experimental, descriptive study is performed in the Microbiology Laboratory of Shahrekord University (Iran) from September 2018 to March 2019. Two cocktails of staphylophages were isolated from Isfahan (Iran) urban sewage samples. The double-layer agar method was used to detect lytic phages. Morphology characteristic by transmission electron microscopy (TEM) images was used to identify staphylophages. One hundred and thirty three S. aureus were isolated from clinical samples of two teaching hospitals in Isfahan and Shiraz, Iran. Methicillin resistance and the presence of the mecA gene were determined by the disk diffusion method and polymerase chain reaction (PCR) assay, respectively. The phage susceptibility of mecA positive isolates was determined by plaque assay. Results: Two staphylophage cocktails were prepared, which had lytic effects on forty-four MRSA isolates. Cocktails 1 and 2 lysed 19 (14.2%) and 25 (18.7%) isolates, respectively. Of 133 S. aureus isolates, 88.7% carried the mecA gene. Conclusions: Different bacteriophages in two phage cocktails had relatively good lytic effects on S. aureus clinical isolates. Therefore, phage cocktails may be an appropriate alternative to antibiotics against S. aureus.

Download Full-text

Susceptibility of Clinical Isolates of Staphylococcus aureus to Ceftaroline

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/46121.14442 ◽

2021 ◽

Author(s):

Harsha Sreedharan ◽

KB Asha Pai

Keyword(s):

Staphylococcus Aureus ◽

Tertiary Care Hospital ◽

Methicillin Resistance ◽

Descriptive Analysis ◽

Tertiary Care ◽

The United States ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital

Introduction: Methicillin-Resistant Staphylococcus aureus(MRSA) infection is a major global healthcare problem, the prevalence of which varies from 25-50% in India. It is known to cause Skin and Soft tissue Infections (SSI), endovascular infections, endocarditis, pneumonia, septic arthritis, osteomyelitis, and sepsis. Vancomycin is the drug of choice for treating severe MRSA infections. Ceftaroline, a fifth-generation cephalosporin has been approved by the United States Food and Drug Administration (US FDA) for treating acute bacterial SSI caused by susceptible micro-organisms including MRSA, Community acquired respiratory tract infection, MRSA bacteremia and endocarditis. Aim: To assess the susceptibility of clinical isolates of S. aureusto ceftaroline, in a Tertiary Care Hospital. Materials and Methods: This prospective study was conducted in the Department of Microbiology of a Tertiary Care Hospital over a period of two months from June 2019 to July 2019. S.aureus isolates from various clinical samples were screened for methicillin resistance by disc diffusion method using cefoxitin disc and ceftaroline susceptibility of these isolates was assessed by E-strip method. The isolates were classified as ceftaroline susceptible, Susceptibility Dose Dependent (SDD) and ceftaroline resistant respectively as per CLSI guidelines. A descriptive analysis of the data was done and the results were presented as frequencies and percentages. Results: All the S.aureus isolates were found to be susceptible to ceftaroline. Methicillin Sensitive Staphylococcus aureus(MSSA) isolates had lower Minimum Inhibitory Concentration (MIC) when compared to MRSA. The highest MIC among MRSA was 0.5 μg/mL. Conclusion: Ceftaroline can be considered as an effective alternative for treatment of infections caused by MRSA.

Download Full-text

Prevalence of Methicillin Resistant and Virulence Determinants in Clinical Isolates of Staphylococcus aureus

The Open Infectious Diseases Journal ◽

10.2174/1874279301810010108 ◽

2018 ◽

Vol 10 (1) ◽

pp. 108-115

Author(s):

Manjunath Chavadi ◽

Rahul Narasanna ◽

Ashajyothi Chavan ◽

Ajay Kumar Oli ◽

Chandrakanth Kelmani. R

Keyword(s):

Staphylococcus Aureus ◽

Cell Morphology ◽

Methicillin Resistance ◽

Protein A ◽

Clinical Isolates ◽

Clinical Samples ◽

Virulence Determinants ◽

Methicillin Resistant ◽

Alternative Medicines ◽

Mrsa Strains

Introduction:Methicillin-resistantStaphylococcus aureus(MRSA) is the major threat that is a result of the uncontrolled use of antibiotics causing a huge loss in health, so understanding their prevalence is necessary as a public health measure.Objective:The aim of this study was to determine the prevalence of methicillin-resistant MRSA and virulence determinant among associatedS. aureusfrom the clinical samples obtained from various hospital and health care centers of the Gulbarga region in India.Materials and Methods:All the collected samples were subjected for the screening ofS. aureusand were further characterized by conventional and molecular methods including their antibiotic profiling. Further, the response of methicillin antibiotic on cell morphology was studied using scanning electron microscopy.Results:A total 126S. aureuswas isolated from the clinical samples which showed, 100% resistant to penicillin, 55.5% to oxacillin, 75.3% to ampicillin, 70.6% to streptomycin, 66.6% to gentamicin, 8.7% to vancomycin and 6.3% to teicoplanin. The selected MRSA strains were found to possessmecA(gene coding for penicillin-binding protein 2A) andfemA(factor essential for methicillin resistance)genetic determinants in their genome with virulence determinants such as Coagulase (coa) and the X region of the protein A (spa)gene. Further, the methicillin response in resistantS. aureusshowed to be enlarged and malformed on cell morphology.Conclusion:The molecular typing of clinical isolates ofS. aureusin this study was highly virulent and also resistant to methicillin; this will assist health professionals to control, exploration of alternative medicines and new approaches to combat Staphylococcal infections more efficiently by using targeted therapy.

Download Full-text

Detection of inducible clindamycin resistance in Staphylococcus aureus from various samples in a tertiary care hospital

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20195541 ◽

2019 ◽

Vol 7 (12) ◽

pp. 4696

Author(s):

Rohit Kumar ◽

Jagarti . ◽

Mrinmoy Sarma ◽

Gautam Shalini

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistance ◽

Tertiary Care ◽

Antibiotic Sensitivity ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital ◽

Sensitivity Testing ◽

Inducible Clindamycin Resistance

Background: The increasing frequency of MRSA infections and rapidly changing patterns in antimicrobial resistance, led to renewed interest in the usage of Macrolides-Lincosamide-Streptogramin B (MLSB) antibiotics to treat Staphylococcus aureus infection. Clindamycin is an important drug used in the treatment of MRSA and MSSA infection. The aim of this study was to determine inducible and constitutive clindamycin resistance among clinical isolates of Staphylococcus aureus by D-test.Methods: During a period of 6 months from July 2018 to December 2018, a total of 100 Staphylococcus aureus isolated from different clinical samples were subjected to routine antibiotic sensitivity testing by Kirby Bauer’s disc diffusion method. Methicillin-resistance was determined by using the cefoxitin (30 µg) disc. Incidence of MLSBc and MLSBi in Staphylococcus aureus isolates by D-test as per CLSI guidelines.Results: Out of 100 isolates of Staphylococcus aureus obtained from 350 clinical samples, 70(70%) were found to be MRSA and 30(30%) were MSSA. Among 100 Staphylococcus aureus isolates, 40% isolates showed MLSBi resistance, 28% isolates showed MLSBc resistance, 6% isolates showed MS phenotype and 26% isolates showed Sensitive phenotype. MLSBc and MLSBi were found to be higher in MRSA as compared to MSSA (21%, 27% and 7%, 10% respectively). All clinical isolates showed 100% sensitivity to Vancomycin and Linezolid in routine antibiotic susceptibility testing.Conclusions: Continuous surveillance of the MLSB resistance is important and required before the prescription of clindamycin to treat MRSA infections.

Download Full-text

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.

Download Full-text

EVALUATION OF THE METHOSD FOR DETECTION METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS.

Journal of Medicine and Pharmacy ◽

10.34071/jmp.2013.5.4 ◽

2013 ◽

pp. 25-31

Author(s):

Thi Kim Chi Nguyen ◽

Dinh Binh Tran ◽

Thi Nam Lien Nguyen ◽

Van Tuan Mai ◽

Godreuil Sylvain

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Meca Gene ◽

Antibiotic Sensitivity ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Antibiotic Resistant ◽

Methicillin Resistant ◽

Resistant Strains

Objective: To evaluate the infections that caused by Methicillin-resistant Staphylococcus aureus and the value of the tests to detect Methicillin-resistant Staphylococcus aureus. Subjects and Methods: Used routine techniques to culture and isolate S.aureus, test the antibiotic sensitivity by Kirby-Bauerr, determination the Methicillin-resistant Staphylococcus aureus by Oxacillin and cefoxitin disc and PCR in identified the mecA gene Staphylococcus aureus. Results: The rate of Staphylococcus aureus isolated is highest which isolated from pus specimens (55.06%). In 267 strains of Staphylococcus aureus isolated in the Department of Microbiology, Hue Central Hospital the Methicillin resistance Staphylococcus aureus was 61.42%. The level of antibiotic resistant strains of Methicillin-resistant Staphylococcus aureus is higher than that in Methicillin-sensitive strains. Conclusion: Cefoxitin 30 microg disk diffusion method to detect Methicillin resistance is effective for determinate Methicillin-resistant Staphylococcus aureus (sensitivity and specificity are all 100.00%). Key words: Staphylococcus aureus Methicillin-resistant.

Download Full-text

Characteristics of Staphylococcus aureus Isolated From Clinical Specimens in a Tertiary Care Hospital, Kathmandu, Nepal

Microbiology Insights ◽

10.1177/1178636120972695 ◽

2020 ◽

Vol 13 ◽

pp. 117863612097269

Author(s):

Shesh Narayan Kandel ◽

Nabaraj Adhikari ◽

Binod Dhungel ◽

Upendra Thapa Shrestha ◽

Khadga Bikram Angbuhang ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistance ◽

Tertiary Care ◽

Meca Gene ◽

Significant Proportion ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital ◽

Clinical Specimens ◽

Culture Positive

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. mecA gene is considered one of the important virulence factors of S. aureus responsible for acquiring resistance against methicillin. The main objective of this study was to explore the prevalence, antibiotic susceptibility pattern, and mec A gene. Methods: A total of 39 isolates of S. aureus were isolated from 954 clinical specimens processed in Microbiology laboratory of Himal Hospital, Kathmandu. Antimicrobial susceptibility test (AST) was performed by Kirby-Bauer disc diffusion method using cefoxitin, and performed Polymerase Chain Reaction (PCR) for amplification of mecA gene in MRSA isolates. Results: Out of 954 clinical samples, (16.2%; 153/954) samples had bacterial growth. Among 153 culture positive isolates, 25.5% (39/153) were positive for S. aureus. Among 39 S. aureus (61.5%; 24/39) were multiple drug resistant (MDR). On AST, amoxicillin was detected as the least effective while vancomycin was the most effective. The prevalence of methicillin resistance was 46% (18/39) of which 72.2% (13/18) were positive for mecA gene in PCR assay. Conclusion: One in 4 culture positive isolates from the clinical specimens were S. aureus, of which almost two-thirds were MDR. Around half of the MDR showed MRSA and significant proportion of them were positive for mecA gene. This study concludes that the mecA gene is solely dependent for methicillin resistance in S. aureus but the presence of gene is not obligatory. PCR detection of the mecA gene is reliable, valid and can be suggested for the routine use in diagnostic laboratories.

Download Full-text

Occurrence and characteristics of methicillin resistant Staphylococcus aureus and methicillin resistant coagulase-negative staphylococci in raw milk manufacturing

Czech Journal of Food Sciences ◽

10.17221/4443-cjfs ◽

2012 ◽

Vol 29 (Special Issue) ◽

pp. S11-S16 ◽

Cited By ~ 11

Author(s):

M. Vyletělová ◽

H. Vlková ◽

I. Manga

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Meca Gene ◽

Diffusion Method ◽

Biochemical Tests ◽

Coagulase Negative Staphylococci ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Staphylococcal Cassette Chromosome

For monitoring the occurrence of MRSA (methicillin resistant Staphylococcus aureus) and MR-CNS (methicillin resistant coagulase-negative staphylococci), cow’s, goat’s, and sheep’s milks (bulk milks and individual samples) were investigated. Human nasal and throat swabs of the farm staff and nasal swabs of animals were also investigated as well. In total 1729 samples were examined and 634 strains were isolated by means of the cultivation method and used in this study. Generic identification of the staphylococci isolates was done performed by biochemical tests and all S. aureus and CNS isolates were checked by the PCR method for the presence of mecA gene which is responsible for methicillin resistance. The presence of the staphylococcal cassette chromosome mec (SCCmec), Panton-Valentine leukocidin (pvl) and genes encoding toxic shock syndrome toxin (tst) was detected in all strains confirmed as MRSA. The species were also examined for antimicrobial susceptibility by using disk diffusion method with antibiotic disks. S. aureus was the most frequently identified species from the samples tested (n = 557; 32.2%), followed by S. haemolyticus (n = 32; 1.9%), S. chromogenes (n = 24; 1.4%), S. epidermidis (n = 20; 1.2%), and S. caprae (n = 1; 0.16%). Among the resistant staphylococci (n = 49), S. aureus (n = 25; 51%) was found the most frequently, followed by S. epidermidis (n = 17; 34.7%), S. chromogenes (n = 6; 12.2%), and S. haemolyticus (n = 1; 2%). The resistant Staphyloccocus sp. occurred mainly in cow’s milk (MRSA, S. epidermidis, S. chromogenes, S. haemolyticus) and in animal’s swabs (S. epidermidis). One MRSA was also found in goat’s milk and one was isolated from human swab. No resistant strains were found in sheep’s milk. The negative results of the analysed genes presence (pvl, tst) were identical with all MRSA tested. The staphylococcal cassette chromosome mec (SCCmec) was classified as type IV or V.

Download Full-text

Prevalence and antimicrobial susceptibility pattern of Methicillin-Resistant Staphylococcus aureus isolated from various clinical samples of the patients attending in a Tertiary Care Teaching Hospital in Puducherry

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v10i2.721 ◽

2019 ◽

Vol 10 (2) ◽

pp. 1474-1480

Author(s):

Vamsi Muni Krishna P ◽

Sreenivasulu Reddy V ◽

Praveen Kumar V ◽

Suresh P

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Tertiary Care ◽

Diffusion Method ◽

Clinical Samples ◽

Isolation And Identification ◽

Methicillin Resistant ◽

Antimicrobial Susceptibility Pattern ◽

Microbiological Methods

Staphylococci spp has been reported as a major cause of hospital and community-associated infections. Staphylococcus aureus is the most common pathogen causing a variety of infections relatively begins minor skin in sections (abscess. cellulitis, staphylococcal scalded skin syndrome) to live threating systemic infections like endocarditis, septic arthritis, pneumonia joint, and bone infections, toxic shock syndrome. Methicillin resistance was reported in 1961 and emerged in the last several decades as one of the most important nosocomial pathogens which were reported just one year of the launch of methicillin. MRSA now a day a big problem is because it is creating life threating problems medical institutions. The knowledge of MRSA prevalence and current antibiogram profile is necessary for the selection of appropriate treatment for related infections. Isolation and identification of Staphylococcus aureus were done by standard conventional microbiological methods. The Methicillin-resistant Staphylococcus aureus strains were tested by using Cefoxitin 30μg disc on Mueller - Hinton agar and antibiotic susceptibility testing were done by Kirby-Bauer disc diffusion method according to Clinical and Laboratory Standards Insititute guidelines (CLSI). All the 164 MRSA (100%) strains were sensitive to Tigecycline, Vancomycin, Teicoplanin followed by Linezolid (92. 68%). Tigecycline, Vancomycin, Teicoplanin has until now excellent activity against clinical isolates of Methicillin-resistant Staphylococcus aureus.

Download Full-text

Isolation of mecC Gene carrying Methicillin Resistant Staphylococcus aureus in Clinical Samples from a Tertiary Care Institute, Northern India

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/50312.15525 ◽

2021 ◽

Author(s):

Nargis Bali ◽

Biswajyoti Borkakoty ◽

Humaira Bashir ◽

Shaista Nazir ◽

Sayim Wani ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Tertiary Care ◽

Meca Gene ◽

Clinical Isolates ◽

Clinical Samples ◽

Biochemical Tests ◽

Jammu And Kashmir ◽

Methicillin Resistant

Introduction: The MecC Methicillin Resistant Staphylococcus aureus (MRSA) after its initial recovery in 2007 has been reported with varying frequency from different parts of the world. These isolates assume importance due to the fact that with routine testing platforms available for the detection of MRSA they can be misidentified as being methicillin sensitive which can adversely affect the treatment and outcome of infections due to MRSA harbouring the mecC gene. Aim: To evaluate mecC gene carrying MRSA in clinical isolates. Materials and Methods: This retrospective study was conducted in the Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India for a period of three months (May-July 2020). A total of 102 laboratory confirmed isolates of MRSA (based on biochemical tests and cefoxitin disc diffusion results) were subjected to screening for the presence of mecA and mecC gene by Polymerase Chain Reaction (PCR). Deoxyribonucleic Acid (DNA) was extracted using an in house extraction method following which mecA and mecC were amplified in a total reaction volume of 25 μL using 2x PCR master mix, 5 μL of template and 1 μL (0.4 μM final concentration) each of reverse and forward primers specific for the above mentioned genes. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS) software v24.0. Results: All the isolates were confirmed as being methicillin resistant with 96.1% isolates carrying the mecA gene and 3.9% carrying the mecC gene. The mecC MRSA were recovered from pus, swab and endotracheal tip in middle aged men. One of the patient from whose sample mecC MRSA was recovered was suffering from hypertension, diabetes and renal faliure. MRSA exhibited high resistance to all the antimicrobial agents tested however all of them were sensitive to vancomycin and linezolid. Conclusion: The presence of mecC gene in clinical isolates of MRSA is a cause of concern and calls for an extensive and continuous surveillance of such isolates as they can in future be implicated in causing severe human infections.

Download Full-text

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.

Download Full-text