Slide Coagulase Test Research Articles

Isolasi Staphylococcus aureus dari swab tangan penjamah makanan di kantin Universitas Mataram

One of the main qualities of food is seen from the biological safety aspect, such as being free from Pathogenic microorganisms. Staphylococcus aureus is a pathogenic bacterium that can contaminate food ingredients come from the skin of food handlers. S. aureus produces enterotoxins that have a poisoning in consumers.The preliminary observationstated that there were still many food handlers in the Mataram University canteen who did not pay attention to hand hygiene and personal sanitation. This study aims to determine the bacterial contamination of S. aureus swabbed from the hands of food handlers in the Mataram University cafetaria. The method was used in this research is descriptive observational. The research consisted of two stages, namely isolation and biochemical identification. The isolation stage resulted 10 culturable bacterial isolates. All bacteria were able to ferment mannitol on Mannitol Salt Then, the biochemical test identification resulted that all isolates had a positive catalase test, a positive slide coagulase test, Gram-positive, and staphylococci cell. The TSIA test resulted A/A or (acid)/(acid) which indicated that all isolates were able to use diverse carbon sources from sucrose, lactose, glucose. Moreover, other test as sulfur, indole and motility tests were negative. Therefore, all isolates in this study are classified as S. aureus. This research is also a promotive and preventive effort for the campus in implementing hygiene and sanitation for food handlers in the cafetaria.

Antibiotic Susceptibility and Biofilm Production among Coagulase Negative Staphylococci Isolated from Clinical Samples at Tertiary Care Hospital.

Coagulase Negative Staphylococci have been widely associated with medical device implant treatment and immune-compromised patients. Despite having increasing interest in Coagulase Negative Staphylococci, few studies from Nepal have reported the association of these organisms with urinary tract infections, conjunctivitis, high vaginal swabs, and cerebrospinal fluid. This study was carried out to determine antibiotic susceptibility pattern and biofilm production among Coagulase Negative Staphylococci isolated from clinical samples at tertiary care hospital. This study was a hospital based cross-sectional study in which 3690 clinical samples were included. Isolation and identification of isolates was done following standard microbiological protocol. Coagulase Negative Staphylococci were identified phenotypically on the basis of gram staining, slide and tube coagulase test and by various sugar fermentation tests. Antibiotic susceptibility test was done following Kirby Bauer disk diffusion method (Clinical and Laboratory Standards Institute 2020). Biofilm production was determined by Tissue Culture Plate technique. A total of 113 isolates of Coagulase Negative Staphylococci were detected. Among them S. epidermidis (45.1%), S. saprophyticus (23.9%), S. haemolyticus (16.8%), S. hominis (5.3%), S. capitis (2.7%), -----S. cohini (1.8%), S. lugdunensis (1.8%) and S. sciuri (2.7%) were identified phenotypically. All isolates were found to be resistant against Ampicillin and 111 (98.2%) were sensitive against Linezolid.23.9% of CoNS were strong biofilm producers, 19.5% moderate and 56.6 % were non/weak biofilm producers. It requires susceptibility test for prescribing antibiotics against Coagulase Negative Staphylococci in hospital and the misuse of antibiotics should be prevented.

Incidence of Coagulase Negative Staphylococci in Various Clinical Samples in Tertiary Care Hospital, Nepal

Objectives: To determine incidence of coagulase negative Staphylococci (CoNS) in various clinical samples along with the study of their multi drug resistance, methicillin resistance and biofilm formation. Methods: A hospital based cross-sectional study was conducted which included 1875 clinical samples. The isolation and identification of isolates was done following standard microbiological protocol. The CoNS were identified phenotypically on the basis of gram staining, slide and tube coagulase test and through various carbohydrates fermentation tests. Antibiotic susceptibility test was done by Kirby Bauer disk diffusion method (Clinical and Laboratory Standards Institute 2020) whereas biofilm production was determined by Tissue Culture Plate (TCP) technique. Results: A total of 32 CoNS, comprising of 6 species were identified. S. epidermidis (43.8%) was the most common species isolated followed by S. saprophyticus (28.1%), S. haemolyticus (15.6%), S. hominis (6.3%), S. lugdunensis (3.1%) and S. cohini (3.1%). Further, 27 (84.4%) of CoNS were found to be multidrug resistant, 22 (68.8%) methicillin resistant and 8 (25%) showed positive D- test. Strong biofilm production was detected in 9 (28.1%) isolates of CoNS, 10 (31.3%) were moderate biofilm producers and 13 (40.6%) non/weak biofilm producers. The equal distribution, 9 (33.3%) each of strong, moderate and non/weak biofilm producers were found among 27 isolates of MDR. Among 22 methicillin resistant isolates, 9 (40.9%), 7 (31.8%) and 6 (27.3%) were strong, moderate and non/ weak biofilm producers respectively. All isolates were sensitive against Linezolid followed by Cotrimoxazole. Conclusion: The increasing multi drug resistance among CoNS should be rationally approached with the use of proper antibiotics while treating the patients.

Prevalence of Coagulase Negative Strains of Staphylococcus aureus in Clinical Specimens at the University of Benin Teaching Hospital, Benin City, Nigeria

The test for coagulase activity is a simple and non-expensive test for the identification of S. aureus strains from clinical samples in resource-poor settings. The results of these tests have been reported to vary with the source of plasma and with some atypical strains that test negative with the coagulase test. The study was carried out to determine if misidentification of strains of S. aureus exists on account of the reliance on the coagulase tests. Clinical isolates of Staphylococci that tested negative by the coagulase tests from wounds, pus, aspirates, blood cultures and urogenital samples were collected and re-tested by the slide and tube coagulase tests and confirmed to be negative. Each isolate was inoculated onto mannitol sat agar and DNAse agar plates and incubated at 37oC for 18 h. Isolates that fermented mannitol and showed a positive DNAse test were 25/366 (6.8%). The highest number of coagulase-negative Staphylococcus aureus (CNSA) occurred within blood culture samples 25.7% and in wound, pus and aspirates, 6.9% and the least proportion, 2.9% from urogenital samples. The generation of CNSA strains is strongly associated with severely-ill patients and the potential for the administration of cell-wall inhibiting antibacterial agents may have important roles to play in the emergence CNSA. The inclusion of DNAse test in the routine identification of staphylococci is advocated especially when an isolate has tested coagulase-negative.

Evaluation of conventional methods for species identification of Staphylococcus aureus using MALDI-TOF MS, protein identification and quantification

Objectives: This study aimed to evaluate conventional methods for species identification of Staphylococcus aureus by MALDI-TOF MS. Additionally, the representatives of different species were used to analyze protein expression. Materials and methods: A total of 185 non-duplicated clinical S. aureus identified using the conventional method (colony morphology, Gram’s stain, slide coagulase test, tube coagulase test, catalase test, and mannitol fermentation) was confirmed the identification by MALDI-TOF MS and analyzed by Mass spectral profiling (MSP) and Principal component analysis (PCA). The representatives of different species reported by both methods were confirmed using 16SrRNA sequence and analyzed proteins expression by timsTOF MS. Results: All S. aureus suspected isolates could discriminate among species by MALDI-TOF MS including S. aureus (N=151, 81.6%), S. argenteus (N=32, 17.3%), S. hominis (N=1, 0.5%), and S. haemolyticus (N=1, 0.5%). Using 16S rRNA genebased analysis, S. aureus and S. argenteus could not differentiate from each other. Protein expression of S. aureus was similar to S. argenteus. These genes including rpsT, Huti, pyrF, atpD.1, cpfC, SAUA300_0786, atl.1, and MW2416 showed higher expression in S. aureus (MS076) than S. argenteus (MS060), S. haemolyticus (MS095) and S. hominis (MS060). Conclusion: MALDI-TOF MS provides an excellent tool for accurately species identification of staphylococci. S. aureus expressed protein analyzed higher than the other 3 species. The highest protein expression in S. aureus implies the most virulence of this strain.

Study of antibiotics sensitivity pattern and molecular characterization of Staphylococcus aureus isolated from human and animal pyogenic cases.

Staphylococcus aureus has been described as the most common cause of human and animal diseases and has emerged as a superbug due to multidrug resistance. Considering these, a total of 175 samples were collected from pyogenic cases of humans (75) and animals (100), to establish the drug resistance pattern and also for molecular characterization of human and animal isolates. Thermonuclease (nuc) gene amplification was used to confirm all presumptive S. aureus isolates and then, antibiotic sensitivity and slide Coagulase tests were used for phenotypic characterization of isolates. Following that, all the isolates were subjected to PCR amplification to detect the existence of the Methicillin-resistant (mecA) and Coagulase (coa) genes. Lastly, typing was done using the Randomly Amplified Polymorphic DNA-PCR. The overall prevalence of S. aureus in human and animal samples was found to be 39.4%. Drug sensitivity revealed the highest resistance against the β-lactam antibiotics such as ampicillin (94.8%) and penicillin (90.6%), followed by cephalosporin (cefixime-67.7%) and quinolone (ciprofloxacin-52.1%) group of drugs. The drug sensitivity was the highest against antibiotics like chloramphenicol (95%) followed by gentamicin (90%). Among the 69 S. aureus isolates, the overall presence of MRSA was 40.5% (27.5% and 50% in human and animal isolates, respectively). Total 33 isolates exhibited coa genes amplification of more than one amplicons and variable in size of 250, 450, 800, and 1100bp. The RAPD typing revealed amplification of five and six different band patterns in humans and animals, respectively, with two common patterns suggesting a common phylogenetic profile.

A vancomycin resistance-associated WalK(S221P) mutation attenuates the virulence of vancomycin-intermediate Staphylococcus aureus

IntroductionVancomycin-intermediate Staphylococcus aureus (VISA) is typically associated with a decline in virulence. We previously reported a WalK(S221P) mutation that plays an important role in mediating vancomycin resistance in VISA XN108. Whether this mutation is implicated in bacterial virulence remains unknown. ObjectivesThis study aimed to investigate the effect of WalK(S221P) mutation on the virulence of VISA and the underlying mechanism of this effect. MethodsThe influence of WalK(S221P) mutation on VISA virulence and its underlying mechanism were explored using animal models, RNA-seq analysis, RT-qPCR, hemolytic assay, slide coagulase test, Western blot, β-galactosidase assay, and electrophoresis mobility shift assay (EMSA). ResultsCompared with XN108, WalK(S221P)-reverted strain XN108-R exacerbated cutaneous infections with increased lesion size and extensive inflammatory infiltration in mouse models. The bacterial loads of S. aureus XN108-R in murine kidney increased compared with those of XN108. RNA-seq analysis showed upregulation of a set of virulence genes in XN108-R, which exhibited greater hemolytic and stronger coagulase activities compared with XN108. Introduction of WalK(S221P) to methicillin-resistant S. aureus USA300 and methicillin-susceptible strain Newman increased the vancomycin resistance of the mutants, which exhibited reduced hemolytic activities and decreased expression levels of many virulence factors compared with their progenitors. WalK(S221P) mutation weakened agr promoter-controlled β-galactosidase activity. EMSA results showed that WalK-phosphorylated WalR could directly bind to the agr promoter region, whereas WalK(S221P)-activated WalR reduced binding to the target promoter. Inactivation of agr in S. aureus did not affect their vancomycin susceptibility but mitigated the virulence alterations caused by WalK(S221P) mutation. ConclusionThe results of our study indicate that WalK(S221P) mutation can enhance vancomycin resistance in S. aureus of diverse genetic backgrounds. WalK(S221P)- bearing S. aureus strains exhibit reduced virulence. WalK(S221P) mutation may directly impair the activation of the agr system by WalR, thereby decreasing the expression of virulence factors in VISA.

Species distribution and antibiogram of coagulase negative Staphylococci isolated from various clinical specimens in a tertiary care hospital

Coagulase Negative Staphylococci (CoNS) are common inhabitants of skin and mucous membrane, may act as pathogens causing fatal infections especially in immunocompromised patients. CoNS mainly cause infections involving biofilm on implanted biomaterials. Increase in antimicrobial resistance causes difficulties to treat life threatening infections. Despite their growing importance, their speciation is rarely done. Therefore, the present study is undertaken to identify CoNS to the species level and to know their antibiotic susceptibility pattern along with rate of MRCoNS.250 isolates from various clinical specimens were considered in this study. The isolates were identified by colony morphology, Gram staining, catalase, slide and tube coagulase test. Speciation was done by Novobiocin resistance, urease activity, ornithine decarboxylase, pyrrolidonylarylamidase and aerobic acid production from mannose. The antimicrobial susceptibility was performed by Kirby-Bauer's disc diffusion method as per CLSI guidelines.Among 250 CoNS isolates, commonest species identified was (59.2%) followed by (19.6%) and (12.4%). They were commonly isolated in the age group 21 to 30 years (26.8%) and among males(58%). Total of 33.2% were isolated from pus followed by blood(21.6%). Majority species expressed resistance towards nalidixic acid(97.2%) followed by Penicillin(94%), 74.4% to Amoxicillin-Clavulanic acid and 66.4% to Cotrimoxazole. All the isolates were sensitive to Vancomycin. Methicillin resistance among CoNS was 73.2%. : The increased recognition of pathogenic potential in CoNS and emergence of drug resistance among them demonstrates the need to adopt simple laboratory methods to identify the species and determine the antibiotic resistant patterns to help the clinicians in treating the infections caused by CoNS.

Occurrence of Staphylococcus piscifermentans among Apparently Healthy Ruminants and Their Handlers in Maiduguri, Borno State, Nigeria

This study was conducted to determine the occurrence and antimicrobial susceptibility of Staphylococcus pisifermentans nasal colonization among apparently healthy ruminants and their handlers in Maiduguri, Borno State, Nigeria. A total of six hundred and five (605) samples were collected aseptically using sterile swab sticks (Oxoid, UK) using simple random technique from the ruminants and their human handlers at the Maiduguri central abattoir and livestock market (Kasuwan shanu). One hundred and fifty-one (151) samples were collected from each of the species (cattle, sheep and goat) while 152 samples were collected from animal handlers. The samples were immediately subjected to standard bacteriological analysis. A total of 195 (32.2%) coagulase negative Staphylococcus species (CoNS) were presumptively identified, out of the 195 identified CoNS, 9 (4.62%) was Staphylococcus pisifermentans nasal colonization. The results revealed that out of 9 isolates, S. pisifermentans was highly isolated 4(8.3%) from sheep, followed by cattle and human handlers 2 (3.8%) respectively and the least was from goats 1 (2.3%). Meanwhile, all the 9 (4.62%) isolates were negative for both tube and slide coagulase test. However, they were positive for DNase, Omithine Decarboxylase (ODC) test, betta – hemolysis and synergistic hemolysis. 4(44.4%) of the 9 isolates were positive for Staphylococcus Protein A (SPA) virulence gene, none 0(0%) for mecA virulence gene, and 5(55.6%) were positive for slime (Biofilm) production. The antibiotic susceptibility pattern of these isolate was found to be highly variable to all the used drugs. It is therefore concluded that Staphylococcus pisifermentans isolated from these ruminants and their handlers contain virulence genes which could be responsible for pathogenicity. There is need for more studies using higher technologies in other parts of the country to reveal the through status of the disease in Nigeria.

Antibiotic resistance properties of Staphylococcus epidermidis isolated from hospitals in Selangor

A total of 89 Coagulase-Negative Staphylococci (CoNS) samples used in this study were collected from clinical hospitals in Selangor. These isolates were grown on Mannitol Salt Agar (MSA) to screen for pink colonies that do not reduce mannitol which is a characteristic of CoNS. The purified isolates were subjected to standard biochemical tests which include Gram stain, slide coagulase, catalase, and urease test. Identification of Staphylococcus epidermidis was performed using the tuf gene sequencing method which confirmed the species at a total of 60 out of the 89 isolates. When tested against several antibiotics, 41.7% of the isolates were found to be resistant to cefoxitin followed by erythromycin (38.3 %), gentamicin (16.7 %), rifampin (16.7 %), clindamycin (15.0 %), and ciprofloxacin (8.3 %). In contrast, all of the S. epidermidis isolates were sensitive against linezolid. This supports the use of linezolid in the current treatment of S. epidermidis infections. Hence, the speciation of S. epidermidis and its antibiotic resistance patterns may further establish their role as a significant pathogen and help in initiating proper antimicrobial therapy.
 Keywords: S. epidermidis, tuf gene sequencing, antibiotic, linezolid

Isolation and molecular characterization of staphylococcus aureus isolated from clinical cases in broilers

Background: Staphylococcus aureus (S. aureus) causes a difficult problem in the poultry industry because it causes diseases that are difficult to treat due to the resistance of these bacteria to antibiotics and their possession of a battery of virulence and resistance genes in addition to their ability to produce thick biofilms. Method: A cross-sectional study conducted to collect a total of 53 samples from different clinical cases in broilers during the period from August 2019 to February 2020 in Al-Najaf and Karbala cities, The clinical isolates were determined by using the conventional standard biochemical tests. All the specimens cultured on blood agar medium supplemented with 5% blood for primary isolation and selected by using selective media mannitol salt agar (MSA) for confirmation the mannitol fermentation, then subjected to gram’s staining, catalase, oxidase, and further slide coagulase test, then all S. aureus isolates tested by antibiotic susceptibility test, and screened for the presence of mecA and mecC genes using PCR for the detection of MRSA isolates, then subjected to the detection of virulence genes (pvl and eta), antibiotic resistance gene (cfr), identification of integron class 1, biofilm formation assay, the multi-druge resistance profiles (MDR) and multible antibiotics resistance (MAR) indexes were calculated. Results: the isolation rate of S. aureus from the broilers' clinical samples was 37.7%. The antibiotic susceptibility test revealed that 85% of S. aureus isolates were resistant to one or more of the antibiotic tested. All 53 isolates were assessed for the presence of mecA and mecC genes by using PCR. The mecA gene-specific PCR product was seen in 7 (35%) isolates and considered as MRSA. Among all S. aureus isolates, two isolates were positive for the eta gene, and 15 (75%) isolates harboring integron class 1, while the biofilm formation test revealed that 7 (35%) was positive biofilm producers and three of them were strong producers, consequentlly, 13 (65%) of the isolates were resisted to three or more antibiotics and considered as MDR strains. While pvl, cfr, and mecC gene were not detected among S. aureus isolates. Conclusion: the current study revealed that S. aureus possess a real threat in the poultry industry reflecting a public health problem due to the large acquisition of antibiotic resistance genes by these bacteria, the results indicated a high percentage of isolates having MDR characteristic, and two of them were resistant to all antibiotics tested. In addition to the presence of two MRSA isolates carrying the eta gene, this indicating that they are of human origin.

Isolation and molecular characterization of staphylococcus aureus isolated from clinical cases in broilers

Background: Staphylococcus aureus(S. aureus)causes a difficult problem in the poultry industry because it causes diseases thatare difficult to treatdue to the resistance of these bacteria to antibiotics and their possession of a battery of virulence and resistance genes in addition to their ability to producethick biofilms.Method: A cross-sectional studyconducted to collecta total of 53samples from different clinical cases in broilers during the period from August 2019 to February 2020in Al-Najaf and Karbala cities,The clinical isolates were determined by using the conventional standard biochemical tests. All the specimens cultured on blood agar medium supplemented with 5% blood for primary isolation and selected by using selective mediamannitol salt agar(MSA) for confirmation the mannitol fermentation, then subjected to gram’s staining, catalase, oxidase,and further slidecoagulase test, then allS. aureusisolatestested by antibiotic susceptibility test, and screened for the presence of mecA and mecC genes using PCR for the detection of MRSA isolates, then subjected to the detection of virulence genes (pvl and eta), antibiotic resistance gene (cfr), identification of integron class 1, biofilm formation assay, themulti-druge resistance profiles(MDR)and multible antibiotics resistance (MAR)indexes werecalculated.Results: the isolation rate of S. aureusfrom the broilers'clinical samples was 37.7%. The antibiotic susceptibility test revealed that 85%of S. aureusisolateswere resistant to one or moreofthe antibiotic tested. All 53isolates were assessed for the presence of mecA and mecC genes byusingPCR. The mecA gene-specific PCRproductwas seen in 7 (35%)isolates and considered as MRSA. Among all S. aureus isolates,two isolates were positive for the eta gene, and 15 (75%) isolates harboring integron class 1, while the biofilm formation test revealed that 7 (35%) was positive biofilm producers and three of them werestrong producers,consequentlly, 13 (65%) of the isolates wereresisted to three or more antibiotics and considered as MDR strains.While pvl, cfr, and mecC gene werenot detected among S. aureus isolates.Conclusion:the current study revealed thatS. aureuspossessa real threat in the poultry industry reflectingapublic healthproblemdue to the large acquisition of antibiotic resistance genes by these bacteria,the results indicated a high percentage of isolates havingMDR characteristic, and two of them were resistant to all antibiotics tested.In addition to the presence of two MRSA isolates carrying the eta gene, this indicatingthat they are of human origin.

Comparison of different methods for coagulase production by staphylococci

Aim: To compare different methods for detection of Coagulase production by Staphylococcus aureus. Material and methods: Total 76 species of Staphylococci were isolated from 1083 clinical specimens. Coagulase tests were performed using five different methods including Slide Coagulase test, Tube Coagulase test with diluted human plasma (I), undiluted human plasma (II) and Brain heart infusion (BHI) broth with undiluted human plasma (III) and Coagulase mannitol agar plate method as per standard methods. Results: In Slide Coagulase test, 43 (86%) out of 50 strains gave positive results. In all the three methods of Tube Coagulase test, 50 (100%) out of 50 strains gave positive results. In Coagulase mannitol agar plate method, 48 (96%) out of 50 strains produced opaque zones which indicated coagulase production. Conclusion: This study shows that, in all the five different methods, all three Tube methods gave 100% positive results. Slide coagulase test gave 43 (86%) out of 50 positive results.

The Molecular Detection of mecA Genes of Staphylococcus Aureus

Antibiotic resistance is common among pathogenic bacteria associated with community acquired and nosocomial infections. Methicillin-resistant Staphylococcus aureus (MRSA) infections have become a global health problem particularly in hospital setup causing simple skin infections to life threatening infections. The present study aimed to investigate the presence of mecA genes in MRSA from pigs, using Polymerase Chain Reaction. One hundred S. aureus isolates of blood samples from Pigs in Bariga, Lagos State were collected from Molecular Biology and Biotechnology Unit, Nigeria Institute of Medical Research. Methicillin resistance was determined by Kirby-Bauer’s disc diffusion method. The PCR was used for mecA gene detection from MRSA strains. Twenty-five pure Staphylococcus aureus isolates were identified based on cultural characteristics, biochemical reactions and positive slide coagulase test. Out of these, 11 (44%) strains were MRSA by phenotypic method. Amplification of mecA gene for all the 11 MRSA isolates was negative when visualized on 2% agarose gel electrophoresis. Eleven strains of MRSA were found among Staphylococcus aureus isolates of blood samples from Pigs. The MRSA phenotype observed in the isolates was not the classical mecA mediated resistance. Hence, it is highly recommended to consider alternative mechanisms for β-lactams resistance that may compete with mecA gene in the emergence of MRSA phenomenon in Nigeria.

Urea-Fibrinogen Slide Coagulase Test – A Simple Alternative Method for the Rapid Identification of Staphylococcus aureus

Introduction: The accurate identification of Staphylococcus aureus clinical isolates requires a series of tests. Morphological features and slide coagulase test are two criteria on which S. aureus are identified. Resort to tube coagulase test is sought when results of slide coagulase test are equivocal or doubtful. Both coagulase tests detect the enzymes that convert fibrinogen into fibrin. Human, rabbit or sheep pooled plasma is used as substrate for both tests. Slide coagulase test is simpler and faster as compared to tube coagulase test. The plasma could be carrier of many human and animal pathogens like HIV, HBV, HCV etc. Storage of plasma for longer duration is fraught with chances of contamination. Improperly stored plasma can lead to false positive or negative results. Citrated plasma may be unsuitable for this test if contaminated with citrate utilizing bacteria. Considering the role of S. aureus as a common etiological agent in nosocomial and community infections, there is a need of implementing rapid, easy and cost-effective phenotypic test.Objectives: Considering the disadvantages and risks associated with fresh plasma, this study aims to launch for safer, more reliable substitute with longer shelf life that may provide reliable results for prompt identification of S. aureus by slide coagulase test.Methods: The present work evaluates slide coagulase test (SCT), and urea fibrinogen slide coagulase test (UF-SCT) for S. aureus detection considering Tube coagulase test (TCT) as the reference method. Sensitivity, specificity, positive predictive value and negative predictive values of SCT and UF-SCT were calculated using TCT as gold standard. Results: A total of 150 staphylococcal isolates from different clinical specimens ere selected for the evaluation of coagulase tests. All the specimens were subjected to SCT, UF-SCT and TCT. The UF-SCT showed better sensitivity (95.04%), specificity (100%), PPV (100%), and NPV (82.85%) with reference to TCT. UF-SCT showed similar sensitivity and specificity to SCT. None of the isolates were negative in UF-SCT and positive in SCT. Since UF-SCT does not incorporate plasma directly and at the same time has a very good sensitivity and specificity, it is recommended that UF-SCT could replace SCT for identification of S. aureus.Conclusion: The findings of present study shall encourage laboratories to use the urea-fibrinogen slide coagulase test routinely for the rapid identification of S aureus.Journal of Gandaki Medical College Vol. 10, No. 1, 2017, Page: 5-10

Low prevalence of methicillin resistant Staphylococcus aureus as determined by an automated identification system in two private hospitals in Nairobi, Kenya: a cross sectional study.

BackgroundStaphylococcus aureus (S.aureus) is a major cause of both healthcare and community acquired infections. In developing countries, manual phenotypic tests are the mainstay for the identification of staphylococci with the tube and slide coagulase tests being relied upon as confirmatory tests for S. aureus. The subjectivity associated with interpretation of these tests may result in misidentification of coagulase negative staphylococci as S.aureus. Given that antibiotic resistance is more prevalent in CONS, this may result in over estimation of methicillin resistant S.aureus (MRSA) prevalence.MethodsA review of susceptibility data from all non-duplicate S.aureus isolates generated between March 2011 and May 2013 by the Vitek-2 (bioMérieux) automated system was performed by the authors. The data was generated routinely from processed clinical specimens submitted to the microbiology laboratories for culture and sensitivity at the Aga Khan University Hospital and Gertrude’s children’s hospital both situated in Nairobi.ResultsAntimicrobial susceptibility data from a total of 731 non-duplicate S.aureus isolates was reviewed. Majority (79.2%) of the isolates were from pus swabs. Only 24 isolates were both cefoxitin and oxacillin resistant while 3 were resistant to oxacillin but susceptible to cefoxitin giving an overall MRSA prevalence of 3.7% (27/731). None of the isolates were resistant to mupirocin, linezolid, tigecycline, teicoplanin or vancomycin.ConclusionThe prevalence of MRSA in this study is much lower than what has been reported in most African countries. The significant change in antibiotic susceptibility compared to what has previously been reported in our hospital is most likely a consequence of the transition to an automated platform rather than a trend towards lower resistance rates.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0669-y) contains supplementary material, which is available to authorized users.

Antimicrobial susceptibility pattern of nasal Staphylococcus aureus among Dessie Referral Hospital health care workers, Dessie, Northeast Ethiopia

Staphylococcus aureus is a major pathogen in skin and soft tissue infections. Methicillin-resistant S. aureus (MRSA) is prevalent in most of the countries in which it is sought. MRSA is one of the important pathogens implicated in hospital-acquired infections. The main objectives of this study were to determine the antimicrobial susceptibility pattern of S. aureus isolates, the prevalence of MRSA, and the nasal carriage rate in healthy hospital staff members. A total of 118 health care workers (HCWs) were enrolled using a cross-sectional study design. Nasal swabs were collected and cultured on mannitol salt agar (MSA). The slide coagulase test was performed. Susceptibility testing was carried out on Mueller-Hinton agar using the modified Kirby-Bauer disk diffusion method with 10 antibiotics. Of the 118 HCWs, 34 had S. aureus and 15 had MRSA, with overall positivity rates of 28.8% and 12.7%, respectively. None of the S. aureus isolates were sensitive to penicillin. MRSA isolates were resistant to commonly available antibiotics. Only two (13.3%) of the nasal isolates were vancomycin-resistant. A high rate of nasal carriage and multidrug-resistant S. aureus was found in this study, indicating the need for standard infection control to prevent transmission in our health care setting.

Prevalence and Antibiotic Susceptibility Pattern of Methicillin Resistant Staphylococcus aureus in Tertiary Care Hospitals

Aims: Methicillin resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen in hospitals with hospital based outbreaks world-wide. The present study was carried out to estimate the prevalence of MRSA isolates in clinical specimens and to investigate the sensitivity pattern of resistant isolates against various antibiotics used for treating hospitalized patients. Study Design: The percentage of MRSA was defined as the number of S. aureus isolates resistant to methicillin divided by the total number of S. aureus isolates for which methicillin susceptibility test results were reported. Place and Duration of the Study: The study was conducted during January 2012 to December 2012 at Asian Hospital (tertiary care hospital), Faridabad, Delhi. Methodology: A total of 107 isolates of S. aureus were identified by standard laboratory procedures including catalase test, slide and tube coagulase tests, βhaemolysis on blood agar and growth on mannitol salt agar. Subsequently, antibiotic sensitivity pattern of S. aureus were determined by automated antibiotic susceptibility testing system Vitek 2 compact identification and susceptibility testing (ID/AST) system by using AST-GP-67 card. Result: 23 isolates (21.4%) were identified as MRSA and the remaining 84 (78.6%) were Original Research Article British Biotechnology Journal, 4(3): 228-235, 2014 229 methicillin sensitive S. aureus (MSSA). All MRSA isolates were found to be resistant to penicillin, oxacillin, ciprofloxacin and levofloxacin. The antibiotic resistance pattern of these isolates were high against trimethoprim-sulfamethoxazole (91.3%), erythromycin (47.8%), gentamicin (43.5%), moxifloxacin (42.9%), and less resistance rate was observed against tetracycline (30.4%) rifampicin (13.6%) and clindamycin (4.8%). However, all isolates of Staphylococcus were sensitive to vancomycin, linezolid, nitrofurantoin, quinpristin/daflopristin. Conclusion: Findings presented in this study indicated a high level of resistance to widely used therapeutic agents. An appropriate knowledge on the current antibiotic susceptibility pattern of MRSA is essential for appropriate therapeutic scenario.

Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS).

Coagulase negative Staphylococci (CoNS) are common inhabitants of human skin and mucous membranes. With the emergence of these organisms as prominent pathogens in patients with ocular infections, investigation has intensified in an effort to identify important virulence factors and to inform new approaches to treatment and prevention. To isolate CoNS from ocular specimens; to study the possible virulence factors; speciation of coagulase negative staphylococci (CoNS) which were isolated from ocular complications; antibiotic susceptibility testing of ocular CoNS. The specimens were collected from the target patients who attended the Microbiology Laboratory of a tertiary care eye hospital in Coimbatore, Tamilnadu state, India. The isolates were subjected to tube and slide coagulase tests for the identification of CoNS. All the isolates were subjected to screening for lipase and protease activities. Screening for other virulence factors viz., slime production on Congo red agar medium and haemagglutination assay with use of 96-well microtitre plates. These isolates were identified upto species level by performing biochemical tests such as phosphatase test, arginine test, maltose and trehalose fermentation tests and novobiocin sensitivity test. The isolates were subjected to antibiotic susceptibility studies, based on the revised standards of Clinical and Laboratory Standards Institutes (CLSI). During the one year of study, among the total 260 individuals who were screened, 100 isolates of CoNS were obtained. Lipolytic activity was seen in all the isolates, whereas 38 isolates showed a positive result for protease. A total of 63 isolates showed slime production. Of 100 isolates, 30 isolates were analyzed for haemagglutination, where 4 isolates showed the capacity to agglutinate the erythrocytes. The results of the biochemical analysis revealed that of the 100 isolates of CoNS, 43% were Staphylococcus epidermidis. The other isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin.

Nasal carriage rate of methicillin resistant Staphylococcus aureus among Dessie Referral Hospital Health Care Workers; Dessie, Northeast Ethiopia

BackgroundStaphylococcus aureus is a common cause of community and hospital acquired infections. One of the important sources of staphylococci for nosocomial infection is nasal carriage among hospital personnel. Emergence of drug resistant strains especially methicillin resistant Staphylococcus aureus is a serious problem in hospital environments. The aim of this study was to determine the nasal carriage rate of methicillin resistant Staphylococcus aureus among Dessie Referral Hospital healthcare-workers in Ethiopia.MethodsA cross sectional study was conducted on a total of 118 healthcare workers. Nasal swabs were collected and cultured on Mannitol Salt Agar. Slide coagulase test was performed. An oxacillin susceptibility test was carried out on Muller Hinton agar using modified Kirby-Bauer disc diffusion method.ResultsOf the 118 healthcare workers, 34 (28.8%) carried S. aureus of which 15 were methicillin resistant. Therefore, 12.7% of all HCWs were identified as MRSA carriers. The rate of methicillin resistance among all S. aureus isolates was 44.1% (15/34). MRSA carriage was particularly high among nurses (21.2%). The highest rate of MRSA carriers (57.1%) were workers of surgical wards.ConclusionsThe high rate of nasal MRSA carriage among healthcare workers found in this study indicates the need for adjusted infection control measures to prevent MRSA transmission in our healthcare setting.