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

Diseases ◽  
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.

scholarly journals Prevalence of Methicillin-Resistant Staphylococcus aureus Isolated from Clinical Samples at Narayani Samudayik Hospital, Chitwan, Nepal

2020 ◽  
Vol 7 ◽  
pp. 37-42
Author(s):  
Rama Adhikari ◽  
Bindu Kshetri ◽  
Khem Narayan Sharma ◽  
Santosh Khanal ◽  
Om Prakash Panta ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Susceptibility Pattern ◽  
Cross Sectional ◽  
Mannitol Salt Agar ◽  
Antibiotic Susceptibility Pattern ◽  
Clinical Specimens

Objectives: The main objective of this study was to determine the prevalence of Methicillin Resistance Staphylococcus aureus (MRSA) and MDR bacteria isolated from various clinical specimens from the patients attending Narayani Samudayik Hospital, Chitwan Methods: A cross sectional study was carried in NPI-Narayani Samudayik Hospital, Chitwan from June to December 2017. Altogether, 3610 clinical specimens mainly pus, blood and urine were collected, streaked on Mannitol Salt Agar and Blood Agar and incubated at 37°C for 24 hours. The confirmed colonies of S. aureus were sub-cultured on Nutrient Agar. The antibiotic susceptibility pattern of all isolates S. aureus was determined by Kirby Bauer disc diffusion method. Isolates resistant to cefoxitin (30mcg) were confirmed as MRSA. Result: Among 3610 total clinical samples, 17.6 % (635/3610) showed growth and 95(14.96%) S. aureus were isolated. Higher number of S. aureus was isolated from pus sample (93.15%). Out of 95 S. aureus isolates, 55 (57.89%) were identified as MRSA while 40 (42.10%) were MSSA. Vancomycin, ceftriaxone and chloramphenicol were found to be most effective antibiotic against isolates. Whereas, the least effective antibiotic was cefoxitin followed by amoxiclav, oxacillin and amoxicillin. Conclusion: This study concludes that the overall prevalence of MRSA and MDR among the bacterial isolates is higher compared to other studies. So, it is recommended to monitor the antibiotic susceptibility pattern of pathogens regularly and study the epidemiology of such isolates.  

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

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Mahtab Sadat Madani Boroujeni ◽  
Mohammadreza Mahzounieh ◽  
Azizollah Ebrahimi Kahrizsangi ◽  
Soudabeh Rostami ◽  
Azam Mokhtari ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Plaque Assay ◽  
Clinical Isolates ◽  
Teaching Hospitals ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Methicillin Resistant

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.

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

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.

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

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.

scholarly journals Determination of minimum inhibitory concentration (MIC) of cloxacillin for selected isolates of methicillin-resistant Staphylococcus aureus (MRSA) with their antibiogram

1970 ◽  
Vol 6 (1) ◽  
pp. 121-126 ◽  
Author(s):  
MA Islam ◽  
MM Alam ◽  
ME Choudhury ◽  
N Kobayashi ◽  
MU Ahmed
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Agar Plate ◽  
Susceptibility Test ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Methicillin Resistant ◽  
Antibiotic Susceptibility Test ◽  
Mrsa Strains

The minimum inhibitory concentration (MIC) represents the concentration of antimicrobial at which there is complete inhibition of growth of organism. In order to determine the MIC of cloxacillin, 10 MRSA were previously detected from 40 clinical isolates of Staphylococcus aureus by polymerase chain reaction (PCR). Agar plate dilution test was used to determine the MIC of cloxacillin. The clinical samples were collected from Mymensingh Medical College Hospital, Mymensingh. The study was done in the Department of Medicine, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh from July 2006 to June 2007. The MIC of the cloxacillin for 5 MRSA strains were ≥32 (mg/ml), for 1 MRSA strain was ≥ 128(mg/ml) and for another 4 MRSA strains were above ≥128 (mg/ml). Antimicrobial susceptibility test of the isolated organisms were done by disc diffusion method. On antibiotic susceptibility test, MRSA strains showed 100% resistant against penicillin, oxacillin, cloxacillin and amoxycillin. Cent per cent susceptibility of MRSA was found against vancomycin, ciprofloxacin, erythromycin, fusidic acid and rifampicin. Key words: Minimum inhibitory concentration (MIC), antibiotic resistance, cloxacillin, methicillin-resistant Staphylococcus aureus (MRSA) DOI = 10.3329/bjvm.v6i1.1350 Bangl. J. Vet. Med. (2008). 6 (1): 121-126

scholarly journals Prevalence of Methicillin-resistant Staphylococcus Aureus (MRSA) in a Tertiary Care Hospital in Northern India

2010 ◽  
Vol 2 (02) ◽  
pp. 078-081 ◽  
Author(s):  
Shilpa Arora ◽  
Pushpa Devi ◽  
Usha Arora ◽  
Bimla Devi
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Tertiary Care ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Care Hospital ◽  
Methicillin Resistant ◽  
Sensitivity Pattern

ABSTRACT Aim: The emergence of Methicillin-resistant Staphylococcus aureus (MRSA) has posed a serious therapeutic challenge. We report the prevalence and antibiotic susceptibility pattern of MRSA in the hospitals attached to GMC, Amritsar, Punjab. Materials and Methods: The study comprised of 250 coagulase-positive staphylococci (COPS) isolated from a total of 6743 clinical specimens (like pus, blood, urine, high vaginal swab, sputum, etc.) of patients admitted in hospitals attached to Government Medical College, Amritsar from January 2008−February 2009. Routine antibiotic susceptibility testing was performed and interpreted as per standard guidelines. Methicillin resistance was detected using oxacillin and cefoxitin disc diffusion method, oxacillin screen agar method, and minimum inhibitory concentration using broth macrodilution method. Results: A total of 115 (46%) strains were found to be methicillin resistant. Multidrug resistance was observed in 73% MRSA strains. However, no strain was resistant to vancomycin. Conclusion: Regular surveillance of hospital-associated infection and monitoring of antibiotic sensitivity pattern is required to reduce MRSA prevalence.

scholarly journals 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

2016 ◽  
Vol 5 (1) ◽  
pp. 1-5 ◽  
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

scholarly journals Methicillin-resistant coagulase-negative staphylococci in healthy dogs

2017 ◽  
Vol 62 (No. 9) ◽  
pp. 479-487 ◽  
Author(s):  
J. Siugzdaite ◽  
A. Gabinaitiene
Keyword(s):  
Antimicrobial Resistance ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Diffusion Method ◽  
Coagulase Negative Staphylococcus ◽  
Coagulase Negative Staphylococci ◽  
Phenotypic Properties ◽  
Methicillin Resistant ◽  
Healthy Dogs ◽  
Resistance Rates

The objective of this study was to evaluate the prevalence of coagulase-negative staphylococci in healthy dogs and to determine whether methicillin-resistant staphylococci expressed the mecA gene. Nasal and rectal swab samples were taken from 50 clinically healthy dogs. The prevalence of coagulase-negative staphylococci was evaluated according to phenotypic properties. The agar diffusion method was applied to evaluate antimicrobial resistance and the prevalence of methicillin resistance was determined using PCR analysing the mecA gene. A total of 59 coagulase-negative staphylococcus strains were isolated from the nostrils and rectums of 37 (74%) clinically healthy dogs. The prevalence of coagulase-negative staphylococci in female dogs was significantly higher compared with male dogs (P < 0.05). The results of antimicrobial susceptibility testing showed that 6.7% of the strains were resistant to oxacillin, 23.7% were resistant to penicillin, 22% to ampicillin and 16.9% to erythromycin. The mecA PCR revealed one oxacillin-sensitive and four oxacillin-resistant coagulase-negative staphylococci strains to be mecA carriers. Staphylococcus sciuri (60%) and Staphylococcus warneri (20%) were the most prevalent species among methicillin-resistant coagulase negative staphylococci. High antimicrobial resistance rates for these bacteria were observed against penicillin (100%), ampicillin (100%), oxacillin (80%), erythromycin (80%) and gentamicin (60%). All strains were susceptible to vancomycin and enrofloxacin. It is assumed that methicillin-resistance genes evolved in coagulase-negative staphylococcus and were then horizontally transferred among staphylococci.

scholarly journals Antimicrobial Resistance Patterns and Plasmid Profiles of Methicillin Resistant Staphylococcus aureus Isolated from Clinical Samples

2019 ◽  
Vol 7 (1) ◽  
pp. 8-14
Author(s):  
Gaurav Agrahari ◽  
Amrit Koirala ◽  
Roshan Thapa ◽  
Mahesh Kumar Chaudhary ◽  
Reshma Tuladhar
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Antibiotic Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Plasmid Profile ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Methicillin Resistant ◽  
Plasmid Profiles ◽  
Resistance Patterns

Methicillin-resistant Staphylococcus aureus (MRSA), showing resistance to several antibiotics is a global health problem associated with considerable mortality and morbidity. Antibiotic susceptibility test is a commonly used method to characterize MRSA in epidemiologic studies. Additionally, plasmid profile has been reported to be useful in tracing the epidemiology of antibiotic resistance. This research was conducted to determine the antimicrobial resistance patterns and plasmid profiles of MRSA isolated from clinical samples at KIST Medical College, Imadol, Kathmandu, Nepal. All the clinical specimens sent to the laboratory were processed by standard microbiological techniques and antibiotic susceptibility testing was done by the modified Kirby Bauer disc diffusion method. Further, plasmid profiling was done by Alkaline-lysis method. A total of 27 (38.02%) MRSA were isolated from 71 S. aureus positive samples. MRSA showed the highest resistance towards penicillin (92.60%) and ampicillin (92.60%). In contrast, high levels of sensitivity were shown towards vancomycin (85.19%) and tetracycline (85.19%). Out of 27 MRSA positive samples, single plasmids were isolated from only 6 (22.22%) MRSA isolates. Antibiograms alone are inadequate to accomplish the characterization of MRSA during epidemiological studies. However, plasmid profile analysis in conjunction with the antibiotic susceptibility pattern is valuable in the epidemiological investigation of MRSA, and for reducing MRSA prevalence and treatment cost.

scholarly journals Determination of the frequency, species distribution and antimicrobial resistance of staphylococci isolated from dogs and their owners in Trinidad

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254048
Author(s):  
Sharianne Suepaul ◽  
Karla Georges ◽  
Chandrashekhar Unakal ◽  
Filip Boyen ◽  
Jamie Sookhoo ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Species Distribution ◽  
Antimicrobial Agents ◽  
Methicillin Resistance ◽  
Close Contact ◽  
Common Species ◽  
Diffusion Method ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant

The close contact between humans and their dogs can lead to the commingling of staphylococci and the exchange of mobile genetic elements encoding antimicrobial resistance. The objectives of this study were to determine the species distribution and antimicrobial resistance patterns of staphylococci colonizing canine pets and their owners in Trinidad. Staphylococci were isolated from canine pets and their owners and identified using MALDI-TOF mass spectrometry. Antimicrobial susceptibilities were determined using the Kirby-Bauer disc diffusion method against seven classes of antimicrobial agents. A total of 440 staphylococci were isolated from 112 canine pets and their owners, 53.4% were from canine pets and 46.6% were from owners. Twenty-four species were detected, of which, most isolates (32.5%) belonged to the Staphylococcus intermedius group (SIG). S. sciuri was the most common species of coagulase-negative staphylococci (CoNS) comprising 22.3% of all isolates. Antimicrobial resistance was highest against commonly used antimicrobials, such as penicillin (51.4%), tetracycline (26.1%) and trimethoprim/sulfamethoxazole (18.6%). These antimicrobials also comprised the most common multidrug resistance (MDR) combination. Overall, 19.1% of isolates displayed multidrug resistance. No methicillin-resistant Staphylococcus aureus (MRSA) isolates were detected. However, methicillin resistance was detected in 13.3% and 15.1% of coagulase-positive staphylococci (CoPS) and the CoNS+CoVS (combined CoNS and coagulase-variable staphylococci) group respectively. The presence of methicillin-resistant staphylococci is worrisome because there is the potential for the transfer of these strains between dogs and humans. These strains may act as a reservoir of resistance genes.

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