Tube Coagulase Research Articles

Developing Field Effect Transistor Sensors Based on DNA Probes to Detect Staphylococcus Lugdunensis Bacteria

The goal of this research is to work with an Electrical Double Layer (EDL)-gated Field Effect Transistor (FET) to detect the bacteria Staphylococcus lugdunensis, which can cause a variety of illnesses, including infections of the skin and soft tissues. In rare cases, Staphylococcus lugdunensis can be successfully identified using the combination of a positive catalase test, a negative tube coagulase test, a positive PYR test, and a positive ornithine decarboxylase test. We are employing an Electrical DoubleLayer (EDL)-gated Field Effect Transistor (FET) to speed up the procedure because this test is time consuming and requires a highly competent individual to perform. An ssDNA probe was developed, and effectively immobilized on a gold surface electrode sensor with a square surface, and due to hybridization with the cDNA at different concentrations, electrical signals were generated in the form of current.Our sensor was fabricated using photolithography where the gold electrode surface having 500 μm x 500 μm gate sensing area consisting of each individually addressable sensor arranged in a 1 x 8 array which is the extent gate was expose for immobilization purpose. The sensor was then subjectedto O2 plasma & HCl solution for surface cleaning and fluorescence image of baregold were taken Figure1(b).The Single-Stranded DNA comprising of fluorescent dye (FAM) at 3’ and thiol modifier at 5’ was drop-casted on the gold surface and was incubated for 24 hours at 24°C. After, it went through a washing process in order to remove the unbound ssDNA and fluorescence images were taken. We observed that intensity was higher than that of baregold which indicates that our probe has successfully immobilized on the gold surface Figure 1(b).Figure 1(a) represents the device that we designed. The system works with N-Channel Enhancement-Mode DMOS FET (VN10LP) in which a continuous drain voltage (3.5 V) was applied and the drain current which is the signal, were measured at two distinct gate bias voltage (2V and 3V). cDNA having quencher (BHQ1) at 5’ was diluted in different concentration namely 1fM, 10fM, 100fM and 1000fM. These cDNA with different concentrations were drop-casted on our sensor with Tris-EDTA (TE) buffer as the baseline and starting with lower concentration to higher concentration every after 12 seconds periodically where we record the change in signal as shown in Figure 1(c).After the electrical measurement, fluorescence image was taken and we can observe that it quenched which indicates that the cDNA and the immobilized ssDNA has successfully hybridized which give the signal change. Figure 1: (a) Surface Immobilization Principal Display in Extended Gate EDL BioFETs. (b)Fluorescence value comparison. (c) Plot showing the change in drain current over time for aptamersensors exposed to various cDNA concentrations. Figure 1

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.

A systematic review of the clinical impact of small colony variants in patients with cystic fibrosis

BackgroundCystic fibrosis (CF) is a life-limiting disorder that is characterised by respiratory tract inflammation that is mediated by a range of microbial pathogens. Small colony variants (SCVs) of common respiratory pathogens are being increasingly recognised in CF. The aim of this systematic review is to investigate the prevalence of SCVs, clinical characteristics and health outcomes for patients with CF, and laboratory diagnostic features of SCVs compared to non-small colony variants (NCVs) for a range of Gram-positive and Gram-negative respiratory pathogens.MethodsA literature search was conducted (PubMed, Web of Science, Embase and Scopus) in April 2020 to identify articles of interest. Data pertaining to demographic characteristics of participants, diagnostic criteria of SCVs, SCV prevalence and impact on lung function were extracted from included studies for analysis.ResultsTwenty-five of 673 studies were included in the systematic review. Individuals infected with SCVs of Staphylococcus aureus (S. aureus) were more likely to have had prior use of the broad-spectrum antibiotic trimethoprim sulfamethoxazole (p < 0.001), and the prevalence of SCVs in patients infected with S. aureus was estimated to be 19.3% (95% CI: 13.5% to 25.9%). Additionally, patients infected with SCVs of Gram-negative and Gram-positive pathogens were identified to have a lower forced expiratory volume in one second percentage predicted (-16.8, 95% CI: -23.2 to -10.4) than those infected by NCVs. Gram-positive SCVs were commonly described as small and non-haemolytic, grown on Mannitol salt or blood agar for 24 h at 35°C and confirmed using tube coagulase testing.ConclusionThe findings of this systematic review demonstrate that SCVs of S. aureus have a high prevalence in the CF community, and that the occurrence of SCVs in Gram-positive and Gram-negative pathogens is linked to poorer respiratory function. Further investigation is necessary to determine the effect of infection by SCVs on the CF population.

Using Protein Fingerprinting for Identifying and Discriminating Methicillin Resistant Staphylococcus aureus Isolates from Inpatient and Outpatient Clinics.

In hospitals and other clinical settings, Methicillin-resistant Staphylococcus aureus (MRSA) is a particularly dangerous pathogen that can cause serious or even fatal infections. Thus, the detection and differentiation of MRSA has become an urgent matter in order to provide appropriate treatment and timely intervention in infection control. To ensure this, laboratories must have access to the most up-to-date testing methods and technology available. This study was conducted to determine whether protein fingerprinting technology could be used to identify and distinguish MRSA recovered from both inpatients and outpatients. A total of 326 S. aureus isolates were obtained from 2800 in- and outpatient samples collected from King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia, from October 2018 to March 2021. For the phenotypic identification of 326 probable S. aureus cultures, microscopic analysis, Gram staining, a tube coagulase test, a Staph ID 32 API system, and a Vitek 2 Compact system were used. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), referred to as protein fingerprinting, was performed on each bacterial isolate to determine its proteomic composition. As part of the analysis, Principal Component Analysis (PCA) and a single-peak analysis of MALDI-TOF MS software were also used to distinguish between Methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA. According to the results, S. aureus isolates constituted 326 out of 2800 (11.64%) based on the culture technique. The Staph ID 32 API system and Vitek 2 Compact System were able to correctly identify 262 (80.7%) and 281 (86.2%) S. aureus strains, respectively. Based on the Oxacillin Disc Diffusion Method, 197 (62.23%) of 326 isolates of S. aureus exhibited a cefoxitin inhibition zone of less than 21 mm and an oxacillin inhibition zone of less than 10 mm, and were classified as MRSA under Clinical Laboratory Standards Institute guidelines. MALDI-TOF MS was able to correctly identify 100% of all S. aureus isolates with a score value equal to or greater than 2.00. In addition, a close relationship was found between S. aureus isolates and higher peak intensities in the mass ranges of 3990 Da, 4120 Da, and 5850 Da, which were found in MRSA isolates but absent in MSSA isolates. Therefore, protein fingerprinting has the potential to be used in clinical settings to rapidly detect and differentiate MRSA isolates, allowing for more targeted treatments and improved patient outcomes.

Detection of biofilm formation in multi-drug resistant Staphylococcus aureus among clinical isolates in Zaria metropolis, Kaduna, Nigeria

Antimicrobial resistance are associated with several virulence factors such as biofilm. The biofilm formation ability of S. aureus complicates effective therapeutic management of infections. In this research, we intend to observe biofilm formation in S. aureus using two in vitro phenotypic methods: tissue culture plate and Congo red agar as well as biofilm associated genes Ica A B &amp; D and 16SrRNA. A total of 150 presumptive coagulase positive staphylococcal isolates from all specimens (blood, urine, high vaginal swab, wound swab, ear swab, endocervical swab) submitted to the microbiology laboratory of the selected hospitals were collected. Seventy-three (73) or 48.7% of the isolates were identified as coagulase positive Staphylococcus using microbiology standard methods (tube coagulase test, growth on mannitol salt agar &amp; Dnase agar). Using microgen staph identification kit, the isolates were further characterized into various Staph spp. Disc agar diffusion method was used for eleven (11) antibiotics susceptibility test while vancomycin screening agar and BMD (Broth Micro dilution) MIC test was used for vancomycin susceptibility evaluation. Indirect observation of biofilm was performed using congo red agar (CRA) and Microtitre plate assay method. PCR and sequencing were conducted on the isolates to molecularly detect the presence of 16SrRNA, IcaA, IcaB, IcaD genes. Susceptibility of S aureus (21%) isolates tested against 12 different categories of antibiotics shows 4(27%) not multidrug resistant (MDR), 7(47%) were MDR and 4 (27%) were extensively drug resistant (XDR). High percentage (74%) of Multiple antibiotic resistant index at ≥0.3 suggested that the isolates originated from an environment where antibiotics are often used. Biofilm assessment of MDR S aureus isolates revealed that 9(82%) and 11 (100%) of the isolates were biofilm formers using Congo Red Agar method and Microtiter plate assay respectively. All isolates amplified with 16SrRNA primer signifying all are S. aureus, 100% of the isolates amplified with IcaA, 90% isolates amplified with IcaD, and 50% isolates amplified with IcaB. We can conclude that there is high prevalence of Biofilm forming S. aureus strains in the hospitals studied. This result should be born in mind by clinicians while prescribing medication for S. aureus positive conditions. Hospital managements should be proactive in preventing the preservation of the biofilm formers in their hospital environment through adequate sanitary and disinfection protocols. It is also necessary for clinician to note that nitrofurantoin, linezolid and vancomycin were most effective against the biofilm producing S. aureus and microtitre plate assay method was observed to be most reliable assay in the study of biofilm.

Prevalence and Susceptibility of Staphylococcus aureus Nasal Carriage Strains Isolated from Haemodialysis Patients

Introduction: Staphylococcus aureus is part of the normal human flora that can commonly be found on the skin and mucous membranes of the nasal area. However, in immunosuppressed patients such as those with kidney failures, colonization can potentially lead to infection. There is a concern of increasing antibiotic resistance in S. aureus. This study aimed to determine the prevalence of S. aureus nasal colonization and its antimicrobial susceptibility among haemodialysis-dependent populations. Methods: A cross-sectional study at the Nephrology Unit, Hospital Canselori Tuanku Mukhriz (HCTM) was conducted among haemodialysis-dependent patients between February 2017 to February 2018. Nasal swabs were obtained and cultured on mannitol salt agar. S. aureus isolates were identified by gram staining, tube coagulase and Deoxyribonuclease (DNase). Cefoxitin disc (30 µg) were used to identified the presence of MRSA (methicillin-resistance S. aureus). The S. aureus colonies were further tested against six antibiotics using Kirby Bauer disc diffusion. Result: A total of 134 patients were recruited. S. aureus isolates were detected from 27 patients (20.1%). All S. aureus were phenotypically identified as methicillin-sensitive S. aureus (MSSA) based on the cefoxitin disc. Teicoplanin and linezolid were the most effective with 100% susceptibility. S. aureus exhibited a high resistance rate towards erythromycin (29.6%). No MRSA was isolated in this study. Conclusion: This study highlighted the high prevalence of S. aureus nasal colonization in haemodialysis patients. Teicoplanin and linezolid were found to be the most effective antibiotics against isolated S. aureus.

Phenotypic and Genotypic Identification of Typical and Atypical Staphylococcus aureus Isolated From Bovine Milk Samples

This study aimed to determine the phenotypic and genotypic identification and differentiation of typical coagulase positive Staphylococcus aureus (CPSA) and atypical coagulase negative Staphylococcus aureus (CNSA) from other Staphylococci isolated form bovine milk. Out of 111 milk samples, 67 Staphylococcus strains were isolated, phenotypically, based on resistance to Acriflavine; Staphylococcus aureus (S. aureus) was detected in 44 isolates of them (30 CPSA strains and 14 CNSA strains). Twenty five from CPSA and 5 from CNSA isolates were positive for slime production on Congo red agar plates. Genotypically, the all five tested typical Staphylococcus aureus (CPSA) as well as three atypical Staphylococcus aureus (CNSA) strains encoded all investigated genes (nuc, spa-x and clfA), while the other two atypical CNSA strains, one encoded only nuc gene and the other encoded both nuc and clfA genes. Acriflavine sensitivity test must be included in the routine of phenotypic identification S. aureus as the gold method together with tube coagulase test. PCR analysis is most important confirmation method by detection of nuc gene. Genotypically both typical and atypical S. aureus isolates are virulent. Typical and atypical S. aureus isolated from isolated from bovine milk samples sold in dairy shops were with higher percentage than subclinical mastitic milk samples threating public health hazard. Attention must be paid toward detection and identification of atypical tube coagulase negative S. aureus strains.

Antibacterial Activity of Cinnamomum Zeylanicum Essential Oil Against Methicillin-resistant Staphylococcus Aureus Strains Isolated From Skin Lesions In Patients With Psoriasis

Background and Objectives: Psoriasis is a chronic and inflammatory skin disease, which is has no definitive cure. Several microbial agents have been identified that have a role in the exacerbation of psoriasis, one of which is Staphylococcus aureus. Increased Methicillin-resistance Staphylococcus aureus (MRSA) strains is a major problem worldwide. This study aims to evaluate the antibacterial effect of Cinnamomum zeylanicum essential oil on MRSA strains isolated from skin lesions in patients with psoriasis. Methods: In this study, participants were 140 patients with psoriasis referred to the dermatology and rheumatology clinic of Shariati Hospital in Tehran, Iran. Diagnostic tests including gram staining, catalase test, tube coagulase test, mannitol fermentation test, and deoxyribonuclease test were performed. To identify the phenotype of MRSA strains, methicillin susceptibility testing was performed using cefoxitin by disk diffusion method. The antimicrobial activity of Cinnamomum zeylanicum essential oil was investigated by broth microdilution method and its minimum inhibitory concentration against MRSA strains was calculated. Results: Of 140 patients, 43.57% had infection with Staphylococcus aureus and 14.28% had MRSA infection. There was no significant relationship between gender, age and sampling area in patients with MRSA infection. The results showed that Cinnamomum zeylanicum essential oil had antimicrobial effects on MRSA strains. Conclusion: The Cinnamomum zeylanicum essential oil can be a suitable alternative to antibiotics for the control and treatment of skin infections caused by Staphylococcus aureus.

PREVALENCE OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS AND OTHER STAPHYLOCOCCAL NASAL CARRIAGES AMONG HEALTHCARE WORKERS, PHRAMONGKUTKLAO HOSPITAL

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a group of S. aureus strains containing the SCCmec gene causing beta-lactam antibiotic resistance. MRSA is common in healthcare settings and can cause serious problems.&#x0D; Objective: The study aimed to investigate the prevalence of MRSA nasal colonization among privates of the Medical Private Company, Phramongkutklao Hospital, including antibiotic susceptibility pattern of S. aureus isolates and risk factors of S. aureus nasal carriage.&#x0D; Methods: Nasal swabs were obtained from the anterior nares of 170 privates. Staphylococcal isolates were identified using a catalase test, tube coagulase test and matrix-assisted laser desorption/ ionization time of flight mass spectrometry (MALDI-TOF MS). MRSA detection was screened using cefoxitin disk diffusion and confirmed using the mecA gene detection and SCCmec typing. Antibiotic susceptibility patterns of S. aureus were examined using the disk diffusion method. A questionnaire was collected from the subjects to determine risk factors for S. aureus nasal carriage.&#x0D; Results: Of 170 subjects, 157 (92.35%) revealed staphylococcal positive, yielding 161 staphylococcal isolates. The prevalence of MRSA, methicillin-resistant Staphylococcus epidermidis (MRSE), and methicillin-susceptible Staphylococcus aureus (MSSA) nasal carriage was 0.59, 1.18 and 8.82%, respectively. The MRSA isolate carried mecA revealing SCCmec type II. The MSSA isolates indicated low resistance to tetracycline (13.3%), whereas the MRSA isolate resisted ciprofloxacin, clindamycin, erythromycin, gentamicin, oxacillin and tetracycline. Using multiple logistic regression analysis, a significant risk factor for S. aureus nasal carriage was utensil sharing (adjusted odds ratio=4.41; 95% CI=1.33-14.61).&#x0D; Conclusion: Healthcare-associated MRSA existed among privates of the Medical Private Company. An associated risk factor for acquiring S. aureus was utensil sharing which could be used to help improve prevention and control management among privates.

Methicillin-Resistant Staphylococcus aureus in Diabetic Foot Infections: Protein Profiling, Virulence Determinants, and Antimicrobial Resistance

Staphylococcus aureus (S. aureus) is one of the most prevalent bacterial pathogens recovered from diabetic foot infections (DFIs). Most S. aureus isolates exhibit methicillin resistance, so treatment is recommended with antimicrobials active against methicillin-resistant S. aureus (MRSA) in patients who have risk factors associated with MRSA infections. The main goal of this study was to see if proteomics and molecular methods could be effective in identifying and distinguishing MRSA recovered from DFIs. Since MRSA is highly resistant to β-lactam antibiotics and usually does not respond to other antimicrobial drugs, we evaluated the resistance of MRSA isolates against different antibiotics. The standard procedures were followed for a culture of 250 skin swabs collected from diabetic foot patients. The phenotypic characteristics of 48 suspected S. aureus cultures were determined via microscopic examination, Gram staining, a coagulase test, a BBL™ Staphyloslide™ Latex test, a Staph ID 32 API system, and a Vitek 2 Compact system. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to examine the protein profile of all isolates, and real-time PCR was then used to identify mecA and PVL virulence genes. S aureus isolates were tested using the Vitek 2 Compact for antimicrobial susceptibility using Gram-positive cards (GP71). Among the 48 bacterial isolates tested, 45 (93.75%), 42 (87.5%), and 46 (95.83%) were positive in tube coagulase, the Staph ID 32 API system, and the Vitek 2 Compact system, respectively. We correctly identified all suspected S. aureus isolates (100%) via MALDI-TOF MS with a score value ≥2.00 and differentiated them into 22/48 MRSA (45.83%) and 26/48 MSSA (54.17%) isolates. A higher peak intensity at masses of 5530 Da, 6580 Da, 6710 Da, and 6820 Da was detected in MRSA, but not in MSSA. All MRSA isolates tested positive for the mecA gene, while all isolates tested negative for the PVL gene. The antibiotic susceptibility results showed that 22 (100%), 20 (90.91%), 19 (86.36%), 18 (81.82%), 17 (77.27%), 15 (68.18%), 13 (59.1%), and 12 (54.55%) MRSA strains were resistant to cefoxitin, daptomycin, erythromycin, benzylpenicillin, ciprofloxacin, oxacillin, and clindamycin, respectively. In contrast, all MRSA strains were extremely susceptible (100%) to linezolid, nitrofurantoin, quinupristin–dalfopristin, tigecycline, and vancomycin. Moreover, 20 (90.91%), 18 (81.82%), and 17 (77.27%) of the MRSA strains exhibited high sensitivity against rifampin, trimethoprim–sulfamethoxazole, and gentamicin, respectively. In DFIs, MALDI-TOF MS is a powerful and accurate method of identifying and distinguishing both MRSA and MSSA isolates. A high level of antimicrobial resistance was found in MRSA isolates, and antibiotic therapy based on antibiotic susceptibility patterns is essential for a successful outcome.

Classical and molecular identification of Staphylococcus aureus isolated from infestation cattle wounds with myiasis in Basrah governorate, Iraq

Thepresent study was carried out to describe some epidemiological facts of myiasis infestations in cattle; therefore, Staphylococcus aureus was isolated and identified from various infested sites with maggots from February to September 2019. It involved three districts (Shatt-Alarab, Al-Qurnah, and Al-Dyr) north of Basrah Governorate/Iraq. A total of 54 herds/owners were visited, with 150 cattle were found to be infested with maggots and diagnosed from different sites of the animal body. The result was indicated that 31% (95%Cl, 26.9-35.4) of examined animals were infested with myiasis, and there were no significant differences detected between sex and ages of the animal groups under study. Staphylococcus aureus was diagnosed using classical methods as morphological characteristics, physiological (coagulase tube method), biochemical tests, and growth on selective medium as Mannitol Salt Agar (MSA) at a percentage of 32% (48/150). Polymerase chain reaction (PCR) was performed to amplify the nuc gene in this isolated species, indicating the presence of nuc size (423) bp compared with a ladder used. The study clearly states that myiasis is a severe threat to cattle populations and that veterinary and agriculture authorities must recall control measures. These measures should be forged to include using a trapping/catch system, applying effective treatment, spraying pesticides, and sterilizing male flies with radiation to inhibit producing offspring.

Direct tube coagulase testing on blood cultures in suspected staphylococcal bacteraemia

Background: Staphylococci are common isolates from blood cultures, appearing as Gram positive cocci (GPC) in clusters. The most clinically important species, Staphylococcus aureus, is identified by a positive tube coagulase or latex agglutination from plate culture, whereas less virulent species are mostly negative. This initial distinction may influence clinical management, but can take up to 48 hours. We proposed tube coagulase testing directly on blood culture broth at the time of flagging, which may reduce the time to reporting coagulase activity by 12 or more hours.

Identification of coagulase negative staphylococcal species from bovine mastitis in India.

Staphylococcal mastitis is a major cause of concern to the dairy industry in India and several countries worldwide. Though Staphylococcus aureus is the major cause, coagulase negative staphylococcal species (CoNS) are being increasingly reported in recent years. To investigate the incidence of coagulase negative staphylococcal species in bovine mastitis. Isolation of staphylococci was carried out from 237 milk samples of cows and She buffaloes with clinical and subclinical mastitis from different regions of Andhra Pradesh and Karnataka. CoNS isolates were identified by tube coagulase test using fresh rabbit plasma and coagulase gene PCR. We employed the biochemical test scheme published elsewhere previously for identification of the CoNS isolates up to species and subspecies levels. Seven representative isolates were identified by 16S rDNA sequencing to check the accuracy of biochemical test based identification. The CoNS constitute the majority of the staphylococcal isolates from mastitis (80/125, 64%) in this region. Using biochemical test scheme, the CoNS isolates from bovine mastitis were identified as S. cohnii sub sp. cohnii, S. simulans, S. capitis sub sp. capitis, S. cohnii sub sp. xylosus, and S. lugdunensis. The CoNS species S. schleiferi, S. haemolyticus, S. sciuri, S. xylosus, S. chromogenes, and Macrococcus epidermidis were identified by 16S rDNA sequencing. The 16S rDNA sequencing is the appropriate method for the identification of CoNS species. This study highlighted coagulase negative staphylococcal species as possible etiological agents of mastitis.

Study the Factors affecting the Production of Coagulase Enzyme from Clinical Bacteria Isolated

This study included isolation and diagnosis of Coagulase Positive Staphylococci bacteria fromclinical samples of (21) samples from the Teaching Hospital for Women and Children in Ramadi andincluded nasal swabs, Ear swabs, Normel skin swabs, Wound swabs, Urine Swabs and Abscesses.These isolates were diagnosed according to phenotypic and biochemical tests and vatic. After diagnosingthe developing colonies, it was found the Gram-positive bacteria formed a percentage (71.42%) of theclinical samples out of the total isolates that gave growth on the culture media, and the Staphylococcipositive for the plasma coagulase enzyme (Coagulase Positive Staphylococci) was found. (71.42%) ofthe total Staphylococci bacteria obtained during isolation and diagnosis of clinical samples and a typeof Staphylococcus positive for coagulase (CPS), Staphylococcus. aureus, was diagnosed based on theSlide and Tube Coagulase Test.The sensitivity of CPS-positive staphylococcus to the antibiotic against the bacteria was tested and itwas found that the most effective antibiotic against S. aureus bacteria was Azithromycin as well as theantibiotic Gentamycin, as indicated by S. aureus has demonstrated resistance to Erythromycin as wellas Ciprofloxacin.The different conditions for the production of the plasma coagulase enzyme (Coagulase) for the bacterialisolate of local number (5) were studied, and it was noticed that there is a great similarity in theseconditions except for some differences. The study and it was noticed that the appropriate temperature inthe production of the enzyme for the local bacterial isolate number (5) is the temperature (35) C, and itwas noticed that the pH that led to the increase in the production of the enzyme is (PH10).After (24hr)incubator , and the results were consistent in terms of good production of the enzyme in the mentionedisolation when using a incubator shaker at a speed (100) .

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.

The role of Staphylococcus lugdunensis as a pathogen in children: a multicentre retrospective study.

Introduction: Staphylococcus lugdunensis (SL), a tube coagulase negative Staphylococcus, is known to be pathogenic in adults, causing mainly skin infections.Gap Statement: Previous studies assessing SL's role in paediatric populations are sparse and are mainly limited to case reports.Aim: Present the clinical characteristics consistent with SL infections and its putative role as a pathogen in the paediatric population.Methodology: A retrospective multicentre study was conducted in four paediatric medical centres in Israel. Patients with isolates of SL presenting between 2009-2019 were included.Results: SL was isolated from 40 patients. Average (±SD) age at presentation was 5.9 (±6.2) years, with 22 (55 %) being female. Skin, soft tissue and musculoskeletal infections were the most common (n=20, 50%) followed by ear infections (n=13, 32.5%). Five cases of urine isolates and two isolates from blood culture samples were also reported. Skin abscess was the most common infection among skin and soft tissue isolates, reported in 17 children (85%) with SL being the only pathogen in 15 (75%). Otitis media was the most common ear infection accounting for 12 (92%) of all cases with SL as the only isolate reported in 6 (46%). Five cases of SL isolates from urine specimens were reported, all of which with poor growth of bacteria and normal urinalysis. Two cases of SL growth in blood culture were found in children presenting with signs and symptoms consistent with invasive blood stream infection.Conclusions: In the paediatric population, studied infections caused by SL are increasingly observed. The results of this study highlight its role as a pathogen in soft tissue infections and its putative role in otitis media and invasive blood stream infections. However, the role of SL as an uropathogen was not established.