Coagulase Test Research Articles

Screening method for Staphylococcus aureus identification in subclinical bovine mastitis from dairy farms.

Background:Staphylococcus aureus is one of the most important contagious bacteria causing subclinical bovine mastitis. This bacterial infection is commonly identified by determine the pathogen in bovine milk samples through conventional technique including coagulase test. However, this test has several disadvantages as low sensitivity, risk of biohazard, cost expensive, and limited preparation especially in local area.Aim:Aim of this study was to compare and assess the screening method, Mannitol fermentation test (Mannitol salt agar [MSA]), and deoxyribonuclease (DNase) test, for S. aureus identification in milk samples.Materials and Methods:A total of 224 subclinical bovine mastitis milk samples were collected from four provinces of Thailand and determined S. aureus using conventional method and also subjected to the screening test, MSA and DNase test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) among both tests were analyzed and compared to the tube coagulase test (TCT), as reference method. Immunological test by latex agglutination and molecular assay by determined spa gene were also used to identify and differentiate S. aureus.Results:A total of 130 staphylococci were isolated by selective media, Gram-stain, and catalase test. The number of S. aureus which identified using TCT, MSA and DNase test were 32, 102, and 74 isolates, respectively. All TCT results were correlated to results of latex agglutination and spa gene which were 32 S. aureus. MSA showed 100% sensitivity, 28.57% specificity, 31.37% PPV, and 100% NPV, whereas DNase showed 53.13% sensitivity, 41.84% specificity, 22.97% PPV, and 73.21% NPV. DNase test showed higher specificity value than MSA but the test presented 26.79% false negative results whereas no false-negative result from MSA when comparing to TCT.Conclusion:MSA had a tendency to be a good preference for screening S. aureus because of its high sensitivity and NPV. The result from this study will improve a choice to use a screening test to diagnose S. aureus of veterinary field for prompt disease controlling and effective treatment.

Phenotypic occurrence of methicillin-resistant <i>Staphylococcus aureus</i> in camels slaughtered at Kano abattoir, Kano, Nigeria

To assess the occurrence of MRSA among camels in Kano abattoir, a total of 300 nasal swabs were collected from camels at the lairage in Kano abattoir, Kano state, Nigeria to isolate and biochemically characterize Staphylococcus aureus and confirm methicillin-resistant Staphylococcus aureus among isolates using oxacillin resistance screening agar basal medium, disc diffusion method, PCR and also through detection of penicillin binding protein 2’. Samples were collected into universal sample bottles containing trypticase soy broth with 6.5% Nacl. amples ere incubated at 37 o C for 24 hrs and sub-cultured on Baird Parker agar (Oxoid Ltd, Basingstoke, UK). Suspect Staphylococcus spp isolates were confirmed using coagulase, DNAse, haemolysis and sugar fermentation tests (mannitol, sucrose, lactose, mannose and xylose). Fifteen of the 42 isolated Staphylococcus aureus were confirmed to be MRSA on oxacillin resistance screening agar basal medium of which 12 were also resistant to oxacillin using disc diffusion method. Five (33.3%) of the 15 isolates were confirmed to be MRSA using the PBP2 latex agglutination test kit. The isolates were however negative for mec A by PCR. The prevalence of Staphylococcus aureus and MRSA was higher in males than in females, but this difference was found to be statistically insignificant (p > 0.05). Multidrug resistance was displayed by all Staphylococcus aureus isolates with 100% resistance to ampicillin and penicillin, but 97.6% of the isolates were susceptible to amikacin and 90% to ciprofloxacin and gentamicin. There was no statistically significant difference in antibiotic resistance between Staphylococcus aureus and MRSA to amikacin, ciprofloxacin, chloramphenicol, cloxacillin, erythromycin, gentamicin, penicillin, tetracycline, sulphamethoxazole, vancomycin ( p-value > 0.0), but there was statistical significance to oxacillin (p = 0.0001; OR = 0.7143). MRSA strains were found in 5% of camels and thus may play a potential role in disseminating the pathogen between animals and humans as well as within the community. Keywords: Camels, Kano abattoir, Occurrence, Methicillin resistant Staphylococcus aureus , Multidrug resistance

Prevalence and molecular characteristics of Staphylococcus aureus, including methicillin resistant strains, isolated from bulk can milk and raw milk products in pastoral communities of South-West Uganda

BackgroundStaphylococcus aureus strains are now regarded as zoonotic agents. In pastoral settings where human-animal interaction is intimate, multi-drug resistant microorganisms have become an emerging zoonotic issue of public health concern. The study of S. aureus prevalence, antimicrobial resistance and clonal lineages in humans, animals and food in African settings has great relevance, taking into consideration the high diversity of ethnicities, cultures and food habits that determine the lifestyle of the people. Little is known about milk carriage of methicillin resistant S. aureus strains (MRSA) and their virulence factors in Uganda. Here, we present the prevalence of MRSA in bulk can milk and raw milk products in pastoral communities of south-west Uganda. We also present PFGE profiles, spa-types, as well as frequency of enterotoxins genes.MethodsS. aureus was identified by the coagulase test, susceptibility testing by the Kirby-Bauer disc diffusion and E-test methods and MRSA by detection of the mecA gene and SCCmec types. The presence of Panton – Valentine Leucocidin (PVL) genes and staphylococcal enterotoxins was determined by PCR, while genotyping was by PFGE and spa typing.ResultsS. aureus were isolated from 30/148 (20.3%) milk and 11/91(12%) sour milk samples. mecA gene carriage, hence MRSA, was detected in 23/41 (56.1%) of the isolates, with 21 of the 23 (91.3%) being SCCmec type V; while up to 30/41 (73.2%) of the isolates were resistant to tetracycline. Only five isolates carried the PVL virulence gene, while PFGE typing revealed ten clusters (ranging from two seven isolates each) that comprised 83% of the sample, and only eight isolates with unique pulsotypes. The largest PFGE profile (E) consisted of seven isolates while t7753, t1398, and t2112 were the most common spa-types. Thirty seven of the 41 strains (90.2%) showed at least one of the eight enterotoxin genes tested, with sem 29 (70.7%), sei 25 (61%) and seg 21 (51.2%) being the most frequently observed genes.ConclusionThis is the first study to demonstrate MRSA and enterotoxin genes in raw milk and its products in Uganda. The fact that over 90% of the isolates carried at least one gene encoding enterotoxins shows a high risk of spread of foodborne diseases through milk in this setting.

Characteristics of Staphylococcus aureus Isolated Smoked Fish Pinekuhe from Traditionally Processed from Sangihe District

Pinekuhe is the local name for smoked scad fish (Decapterus sp.), a traditionally processed fish product from Sangihe Islands whose taste, aroma and form are typical and unique. In this research aims of physiological and biochemical characteristics with pathogenicity isolated S. aureus which the isolated from the product smoked scad fish (Decapterus rusellii) Pinekuhe it was produce and prepared by the local fisherman in Sangihe Island Regency. The isolated that have gathered from this researched was 111 product isolate from the smoke fish Pinekuhe which grown from media MSA. Its had isolated already through the<br />test of physiological comprise, Gram staining and from the test of biochemical e.g., from the test Catalase, Voges-Proskauer, and Fermentation carbohydrate tests (Glucose and Manitol). The characteristics of pathogenicity S. aureus had been done and used by making of Coagulase, Nuklease Thermostabil production<br />and deoksiribonuklease (DNase). The result of this research showing that had still 111 isolating strains that still ingroup which consists of 108 isolated Staphylococcus and from 108 strains to 68 strains that had been test in identifying, as of Staphylococcus aureus with characteristics of Gram positif coccus, catalase positif,<br />Voges-Proskauer positif, and to Fermentation Glucose and Manitol. The 68 isolate S. aureus that characterize from Phatogen principles product Coagulase test, Nuklease Thermostabil and deoksiribonuklease (DNase). S. aureus is dominant (62%) contaminate smoked fish Pinekuhe processed traditional of Sangihe island.

The Prevalence of S. Aureus Nasal Colonisation and its Antibiotic Sensitivity Pattern amongst Primary School Pupils

Staphylococcus aureus is one of the most adaptable human pathogens. Nasal Staphylococcus aureus is the main cause of community-associated staphylococcal infections. This project aimed to study the prevalence of nasal carriage of Staphylococcus aureus and community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) and evaluate their antibiotic susceptibility tests among primary school children at Zakho city, Kurdistan region, Iraq. Nasal swabs were taken from a total of 300 primary school pupils aged 8-12 years. Collected nasal swabs were processed according to the standard bacteriological culture and isolates were identified using mannitol fermentation, Gram stain, catalase test and coagulase test. Antimicrobial susceptibility test was carried out on Muller-Hinton agar (MHA) to determine the susceptibility of S. aureus and CA-MRSA towards antibiotics. 30% (90/300) of the primary school children carried S. aureus. The nasal carriage of MRSA was 4% (12/300) among participants. All MRSA isolates were sensitive to vancomycin, doxycycline, amikacin and ciprofloxacin. This study showed that the incidence of S. aureus and CA-MRSA is comparable with reports from elsewhere. Measures are needed to keep the emergence and transmission of these pathogens to a lowest. Antimicrobial susceptibility testing of all S. aureus isolates is crucial for treatment of MRSA. Further studies are required to detect the risk factors of the acquisition of MRSA.

Nasal carriage of enterotoxigenic Staphylococcus aureus among food handlers in Kerbala city

BackgroundStaphylococcal Food Poisoning (SFP) is an intoxication caused by consumption of improperly prepared or stored foods containing adequate amounts of one (or more) preformed enterotoxin. Previous studies demonstrated that employees who working in the food industry are the main source for spreading foodborne diseases. AimsTo study the prevalence of the staphylococcal enterotoxin genes among the isolates from the food handlers in Holy Kerbala city. Materials and methodsNasal swabs were collected from 332 food handlers. Standard microbiological methods were used to isolate Staphylococcus aureus including, culturing on selective media (mannitol salt agar), coagulase test and API-staph. Multiplex PCR (Polymerase Chain Reaction) using specific primers was used for the detection of staphylococcal enterotoxin genes. Result and discussion100 food handlers out of 332 (30.1%) were found to carry S. aureus, 38 (38%) isolates were found positive in Multiplex PCR for one or more enterotoxin: 16 (16%) were positive for sea, 18 (18%) were positive for seb, 8 (8%) were positive for sec, 6 (6%) were positive for sed and 8 (8%) were positive for see. ConclusionThe prevalence of nasal carriage of S. aureus is high among food handlers in Holy Kerbala city, as well as the percentage of enterotoxin genes among the S. aureus isolates. Therefore, strict measures are necessary to prevent contamination of food with S. aureus isolates during food handling.

MOLECULAR DETECTION AND CHARACTERIZATION OF ESCHERICHIA COLI ISOLATED FROM RAW MILK SOLD IN DIFFERENT MARKETS OF BANGLADESH

The study was intended for molecular detection of E. coli isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying staining characteristics, cultural properties on different selective media, biochemical tests, catalase and coagulase test, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found positive for E. coli. 15 Escherichia coli isolates were amplified by 16S rRNA gene based PCR. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the E. coli isolates were resistant to amoxycillin (86.67%) and erythromycin (73.33%) but sensitive to azithromycin (53.33%), ciprofloxacin (86.67%), gentamicin (86.67%), norfloxacin (80%) and streptomycin (66.67%).

Patterns of infections, aetiological agents and antimicrobial resistance at a tertiary care hospital in northern Tanzania.

To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment. A total of 590 specimens (stool (56), sputum (122), blood (126) and wound swabs (286)) were collected from 575 patients admitted in the medical and surgical departments. The bacterial species were determined by conventional methods, and disc diffusion was used to determine the antimicrobial susceptibility pattern of the bacterial isolates. A total of 249 (42.2%) specimens were culture-positive yielding a total of 377 isolates. A wide range of bacteria was isolated, the most predominant being Gram-negative bacteria: Proteus spp. (n = 48, 12.7%), Escherichia coli (n = 44, 11.7%), Pseudomonas spp. (n = 40, 10.6%) and Klebsiella spp (n = 38, 10.1%). Wound infections were characterised by multiple isolates (n = 293, 77.7%), with the most frequent being Proteus spp. (n = 44, 15%), Pseudomonas (n = 37, 12.6%), Staphylococcus (n = 29, 9.9%) and Klebsiella spp. (n = 28, 9.6%). All Staphylococcus aureus tested were resistant to penicillin (n = 22, 100%) and susceptible to vancomycin. Significant resistance to cephalosporins such as cefazolin (n = 62, 72.9%), ceftriaxone (n = 44, 51.8%) and ceftazidime (n = 40, 37.4%) was observed in Gram-negative bacteria, as well as resistance to cefoxitin (n = 6, 27.3%) in S. aureus. The study has revealed a wide range of causative agents, with an alarming rate of resistance to the commonly used antimicrobial agents. Furthermore, the bacterial spectrum differs from those often observed in high-income countries. This highlights the imperative of regular generation of data on aetiological agents and their antimicrobial susceptibility patterns especially in infectious disease endemic settings. The key steps would be to ensure the diagnostic capacity at a sufficient number of sites and implement structures to routinely exchange, compare, analyse and report data. Sentinel sites (hospitals) across the country (and region) should report on a representative subset of bacterial species and their susceptibility to drugs at least annually. A central organising body should collate the data and report to relevant national and international stakeholders.

Nasal carriage of methicillin resistant Staphylococcus aureus among health care workers at Al Shifa hospital in Gaza Strip

BackgroundNasal carriage of Staphylococcus aureus among hospital personnel is a common cause of hospital acquired infections. Emergence of drug resistant strains especially methicillin resistant S. aureus (MRSA) is a serious problem in hospital environment. Therefore, the aim of this study was to determine the nasal carriage rate of S. aureus and MRSA among Health Care Workers (HCWs) at Al Shifa Hospital, the major hospital in Gaza Strip.MethodsA cross sectional study was conducted on 200 HCWs. Nasal swabs were collected during February — April 2015, and cultured on blood and mannitol salt agar. The isolates were identified as S. aureus based on morphology, coagulase test, DNase test and mannitol salt agar fermentation. Disk diffusion antibiotic susceptibility tests were performed according to the guidelines of the Clinical and Laboratory Standards Institute. MRSA were confirmed by detection of the mecA gene by PCR.ResultsOut of the 200 healthcare workers, 62 (31%) carried S. aureus, of which 51 (82.3%) were MRSA. Therefore, 25.5% of all HCWs were identified as MRSA carriers. MRSA carriage rate was highest among nurses (30.4%) whereas the carriage rate among doctors was (16%). The majority of MRSA carriers were workers of internal medicine department and surgical wards (41.3 and 35% respectively). Out of the 51 MRSA isolates identified by oxacillin disc resistance, 40 were confirmed by PCR targeting the mecA gene. Penicillin showed the highest rate of resistance among MRSA and MSSA isolates (100%).ConclusionsThe high rate of nasal MRSA carriage among healthcare workers found in this study is alarming and highlights the need for adjusted infection control measures to prevent MRSA transmission from HCWs to the vulnerable patient.

Methicillin-resistant Staphylococcus spp. isolated from curd cheese “requeijão” and “especialidade láctea type requeijão” sold in Brazil

ABSTRACT: This study focused on counting Staphylococcus spp. in curd cheeses “requeijão” and “especialidade láctea type requeijão” sold in Brazil, assessing the presence of mecA gene in obtained isolates and establishing antimicrobial resistance profile of the mecA gene positive isolates. To this, a set of 200 samples of these dairy products were evaluated. Low counts of Staphylococcus spp. were observed in these dairy products. All the isolates were determined as coagulase-negative strains using coagulase test and PCR. However, two isolates (3.70%) were carriers of mecA gene and they can be considered as risk for public health. These isolates presented resistance to penicillin, oxacillin and erythromycin. In conclusion, low counts of Staphylococcus were detected in curd cheese “requeijão” and “especialidade láctea type requeijão” sold in Brazil. However, coagulase-negative methicillin-resistant Staphylococcus spp. was detected in these dairy products. This is the first report of the detection of methicillin-resistant Staphylococcus spp. in heat-treated dairy products in Brazil. Results served as a warning to public sanitary authorities to control multidrug-resistant strains in veterinary and human medicine.

Detecting the Presence of Methicillin-Resistant Staphylococcus aureus on Acne Extractor used by Some Beauty Salons in Jatinangor

Background : Over the past few decades, methicillin-resistant Staphylococcus aureus (MRSA) has become a major cause of nosocomial infection and has recently emerged in the community. Community associated MRSA (CA-MRSA) have grown drastically over the years and have mostly manifested as a form of skin infection. The MRSA infection usually occurs in individuals with skin lesions serving as a site of entry for the bacteria. The aim of this study was to determine if MRSA is presence on the acne extractor used by some beauty salons in Jatinangor. Methods : A total of 40 samples were taken from 14 beauty salons in Jatinangor from September to October 2013. The samples were then cultured on mannitol salt agar. The isolated colonies were then gram stained, followed by catalase and coagulase test. The colonies having positive for Staphylococcus aureus (S. aureus) were then tested for cefoxitin susceptibility. Results : Overall 3 of the isolates were positive for S. aureus and none were positive for MRSA. Conclusions : Only a small fraction of the isolates are positive for S. aureus and no MRSA is detected.. [AMJ.2017;4(1):64–8] DOI : 10.15850/amj.v4n1.163

Community-acquired methicillin-resistant Staphylococcus aureus carriage rate and antimicrobial susceptibility in a tertiary center, Iran.

Background:This study was aimed to determine frequency and antimicrobial susceptibility of Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) among colonized patients in outpatient status.Materials and Methods:A total of 2000 nasal nares specimens were collected and inoculated on mannitol salt agar. MRSAs were identified based on mannitol positivity and coagulase test followed by cefoxitin disc diffusion test. Antimicrobial susceptibility of MRSA isolates was performed by E-test method for vancomycin and doxycycline as well as disc diffusion method for sulfamethoxazole-trimethoprim (SMX-TMP), erythromycin, linezolid, and clindamycin. D-test was performed for detection of inducible resistance to clindamycin.Results:Overall, nasal carrier rate of S. aureus and CA-MRSA was estimated 22% and 1.25%, respectively. Out of the 440 S. aureus isolates, 25 isolates were MRSA. All were susceptible to vancomycin and linezolid, and susceptibility rates to SMX-TMP, erythromycin, levofloxacin, doxycycline, and clindamycin were 68%, 44%, 48%, 40% and 44%, respectively; furthermore, 28.5% of resistant isolates to erythromycin had inducible resistance to clindamycin.Conclusion:It seems susceptibility to clindamycin and SMX-TMP, recommended agents for empirical treatment of suspected CA-MRSA, are not promising. Vancomycin and linezolid are effective and reliable antibiotics for the treatment of S. aureus infections.

Prevalence of nasal carriers of methicillin-resistant Staphylococcus aureus among dental students: An in vivo study.

Aim:The aim of this study is to evaluate the prevalence of nasal carriage of coagulase positive methicillin-resistant Staphylococcus aureus (MRSA) among dental students.Materials and Methods:Four hundred dental students, divided into two groups – undergraduates (200) and postgraduates (200), were screened using sterile cotton swabs for carriage of MRSA in anterior nares. The samples were inoculated on HiCrome MeReSa Agar Base-with cefoxitin supplement. Further confirmatory tests were done by Gram-staining, Tube coagulase and Cefoxitin disc diffusion test on Mueller–Hinton agar.Results:MRSA was positive among 25 (12.50%) undergraduates and 49 (24.50%) postgraduates students. Further confirmatory test also showed the same results. MRSA colonization was significantly more in postgraduate students, who are exposed to more number of patients and have put in more clinical hours as compared to undergraduate students who have just entered clinics and have limited clinical exposure.Conclusion:The present study concluded that rate of MRSA colonization was 18.5% in the dental school population. The colonization rate was significantly (P = 0.002%) higher in postgraduate students as compared to undergraduate students emphasizing the need to follow infection control protocols stringently.Clinical Significance:Awareness about MRSA among dental doctors is mandatory so as to prevent transmission of MRSA in dental settings.

Nasal Colonization of Methicillin Resistance Staphylococcus aureus among Food Handlers in the Eateries Obafemi Awolowo University Ile Ife, Nigeria

Food handlers have been recognized to play a major role in the transmission of food borne diseases; contributing significantly to the global incidence and burden of diseases. This study assesses nasal carriage of Staphylococcus aureus among food handlers in the Obafemi Awolowo University eateries. A total of 35 nasal swab samples were collected and analyzed using standard conventional methods of microbial analysis in isolation and identification of S. aureus including catalase, coagulase and DNase tests as well as the antibiotic susceptibility of the isolates. The result showed that the prevalence of nasal carriage of S. aureus in Obafemi Awolowo University eateries was 13 (37.14%). The antibiotic susceptibility shown that all isolates were 100% sensitive to pefloxacin, zinnacel and ciprofloxacin while gentamycin (84.61%), ampiclox (30.77%), amoxicillin (30.77%), rocephin (61.53%), streptomycin (69.23%), septrin (23.07%), and erythromycin (46.18%) respectively. Concerted effort need to be made to educate food handlers and restaurant workers on the importance of personal hygiene and the use of protective gadget like nose masks while handling food products.

Surface Colonization of Health Care Facilities in Hematology by Methicillin Resistance Staphylococcus aureus (MRSA) at Obafemi Awolowo University Teaching Hospital Complex, Nigeria

Gram positive bacteria is not unique to intensive care units but has been increasingly reported in health care facilities, especially among Hematology patients worldwide. We evaluate microbiological disease etiology of Staphylococcus aureus in Hematology and frequency of harboring of pathogens by the facilities, medical equipment, surfaces and the possibility of cross contamination between health care workers including the antibiotic sensitivity pattern of the isolates recovered. Hundred sourced swabbed samples were taking from the facilities/equipment, rails, door knobs, personnel cell phone and other surfaces at hematology wards of the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ile-Ife. Swabs collected were inserted aseptically into test tubes that contain freshly prepared nutrient broth and then incubated at room temperature (37°C). After 24 h, the broth culture was inoculated into mannitol salt agar (MSA) plates using the inoculating loop. The streaking was done and the plates were incubated at 37°C for 24 h. Coagulase and DNAse biochemical test later conducted to establish the Staphylococcus aureus isolates. Out of the 54 Staphylococci sp. obtained from hundred samples taken from different sources of various facilities and equipment in the wards, 25(46.3%) Staphylococcus aureus isolates showed total Staphylococcus aureus contaminant of facilities/environment/equipment where door knobs 7(28.0%) showed higher contamination rate followed by 5(20.0%) bed rails, which is higher than the % constitution of Personnel Stethoscope and cell phones which constituted 4(16.0%) and 3 (12.0%) respectively. All isolates were 98%, 64% and 28% susceptible to vancomycin, chloramphenicol and streptomycin respectively and 100% resistant to penicillin and oxacillin used. It is imperative for optimal patient care in the Hematology that effective aseptic techniques and use of sterile gloves, hand hygiene practices in handling surfaces with constant evaluation of antibiotic sensitivity pattern of pathogens for commonly used antimicrobial agents in a particular environment should be greatly maintained.

Staphylococcus aureus Surface Colonization of Medical Equipment and Environment, Implication in Hospital- Community Epidemiology

Staphylococcus aureus has been known to be a predominant nosocomial infection occurring majorly among immune-compromised patients in hospital environments and other health care facilities. This study was carried out to identify the prevalence of Staphylococcus aureus on fomites in both male and female orthopedic wards, Radiology Department and the hospital environment at the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria. Standard conventional methods of microbial analysis in isolation of S. aureus including catalase, coagulase and DNase tests as well as the antibiograms of the isolates from fomites were determined. Out of 34 (thirty-four) samples collected, 11 samples were confirmed positive for S. aureus isolates with the female ward constituting of 45.5%. Pure cultures of S. aureus isolated were 100% susceptible to both ciprofloxacin and pefloxacin, 69% resistant to amoxicillin and ampiclox, 80% to septrin, 54% erythromycin, 31% streptomycin, 38% rocephin and 15% to gentamycin used. Periodic routine disinfection of hospital environment should be implemented in order to reduce the risk of infection among patients and staff. Protocols to reduce the transmission may need to be extended to hospital beds, trolleys, nurse desk, tables and taps. Frequent need for strict compliance to effective Infection Control Program must be maintained.

Study on the Prevalence and Distribution of Staphylococcus aureus in Raw Cow Milk Originated from Alage Atvet College Dairy Farm, Ethiopia

This investigation was carried out from October 2011-June 2012 to determine the prevalence of Staphylococcus in milk and rate of contamination at farm and milk distribution tank in Alage Agricultural Technical Vocational Educational Training College. Milk samples (row) were cultured on sheep blood agar and incubated. The plates were examined for gross colony morphology, pigmentation and haemolytic characteristics at 24-48 h then presumptive colonies of Staphylococcus aureus was selected and sub cultured on nutrient agar and incubated. Then, bacteria were identified according to its Gram reaction, morphology and the catalase test, tube coagulase test (4 h), haemolysis, pigment production (golden yellow), mannitol and maltose fermentation were used. A total of 170 milk sample of cow were examined for bacteriological status of S. aureus, an overall 28.2% prevalence of Staphylococcus was found. From this, 21.2% was directly from the farm and 35.3% were from milk distributing site to consumers. The total prevalence of Staphylococcus varied among the sample taking site. The prevalence of S. aureus from distributing raw milk site (35.3%) was significantly higher than the prevalence of S. aureus from samples taken directly from the farm (21.2%). From this the study it is considered that Staphylococcosis a potential hazard for the public and contamination rate is high in distribution site which needs improvement of the hygienic status of the personnel’s at distribution site.

Evaluation of HiaureusTM Coagulase Confirmation Kit in Identification of Staphylococcus aureus.

Staphylococcus aureus is a facultative anaerobic Gram positive coccal bacterium whose incidence ranges to different infections. It is a cause of various uncomplicated skin infections, abscesses, septicaemia/bacteraemia, gastroenteritis, endocarditis, toxic shock syndrome and food intoxications. Various methods with varied time, sensitivities, specificities and costs are available, but may not be used as a reliable test for the identification and differentiation of S. aureus. Therefore, there is a need to evaluate newer tests. To compare the conventional tests with a commercial available kit for reliable, cost effective identification and confirmation of S. aureus. The current prospective study was conducted in the Department of Clinical Pathology, Haffkine Institute for a period of six months. A total of 341 clinical isolates of staphylococci isolated from pus, urine, blood culture and sterile body fluids were subjected to conventional tests like Tube Coagulase Test (TCT) using Rabbit Plasma (RP) and Human Plasma (HP), culture media such as Mannitol Salt Agar (MSA) and Deoxyribonuclease (DNase) media in parallel to HiaureusTM Coagulase Confirmation Kit (HACCK), a commercially available kit for identification of S. aureus. Amplification of the femA gene was used as a comparative reference point test to calculate the sensitivity, specificity and concordance values of the conventional tests. Amongst the coagulase based tests, HACCK was 100% sensitive and specific. The TCT using RP was 98.58% sensitive while TCT using HP was less sensitive (95.37%). A total of 100% specificity was observed for TCT using RP while TCT using HP was 96.68% specific. The MSA and DNase media were 97.86% vs 96.44% and 96.67% vs 91.67% sensitive and specific respectively. The combination tests had varying sensitivity and specificity ranges. The HACCK demonstrated 100% concordance with femA amplification and was labelled as an ideal perfect test (κ=1) with MSA as an alternative test for S. aureus identification. The HACCK can be used as an exclusive, reliable and cost effective test for identification of S. aureus. Alternatively, in view of the cost factor MSA either as a single test or in combination with TCT using HP could be used as screening tests and confirm discordant results with HACCK.

Biochemical Characterization and Antibiotic Susceptibility of Coagulase Negative Staphylococci Isolates from Exudates and Body Fluids

Coagulase negative Staphylococci (CoNS) are increasingly being recognized as significant nosocomial pathogens, partly due to the growing appreciation of this group of organisms as opportunistic pathogens or due to increase in the use of transient or permanent medical devices in seriously ill and immunocompromised patients. Aims & Objectives : 1. Isolation of CoNS from exudates and body fluids. 2. Biochemical characterization of CoNS 3. Antibiotic susceptibility pattern of CoNS. Method: 180 CoNS isolated from various exudates and body fluids such as Pus, Wound Swabs, Endotrachial Secretions, Sputum, Branchial Aspitate, Central Lining Tube were collected. All the CoNS isolates were processed in the Microbiology laboratory and identified by colony morphology, Gram staining, Catalase, slide, tube coagulase test, anaerobic acid from mannitol, Deoxyribonuclease.Bacitracin (0.04 U) and furazolidone (100 µg) susceptibilities were done to exclude Micrococcus and Stomatococcus spp. The following biochemical tests were done for the speciation of the CoNS: Urease test, Phosphatase test, Polymyxin B disc test, Novobiocin Disk Test, Ornithine decorboxylase test, Mannitol to acid, voges - proskauer test , Mannose fermentation, Trehalose fermentationand Antibiotic susceptibility testing. Result: Out of 180 isolates, 78 are S.epidermidis ( 43.3%), 63 are S.hemolyticus (35%), 21 are S.hominis (11.6%), 18 are S.lugdunensis (10.0%). Maximum number of CoNS were isolated from pus specimens (58.33%), followed by wound swabs (18.33%). 164 out of 180 strains were negative for both bound and free coagulase. 60 strains were bound coagulase slow positive and free coagulase negative. S. epidermidis was the most frequent isolate and 68 S. epidermidis isolates were identified if Ornithine decorboxylase was considered positive, while negative ten S. epidermidis isolates required inclusion of trehalose and mannitol for speciation. Antibiotic susceptibility testing showed maximum resistance to penicillin (78.3) followed by Chloramphenicol (41.6%). No resistance to vancomycin was seen. Conclusion: The study revealed S. epidermidis is the predominant CoNS from Endotracheal secretions and also pus samples. S.hemolyticus was isolated from pus and central lining tubes, S.hominis and S.lugdunensis were isolated mainly from wound swabs. The present study suggests; if Coagulase -ve Staphylococci are repeatedly isolated from patients with infection they should be taken seriously and ABST done on these isolates for proper diagnosis and treatment especially in nosocomial infections. Keywords: Coagulase negative staphylococci, Antibiotic susceptibility, Clinical isolates of Exudates and body fluids, Biochemical Chemical characterization

Isolation and molecular identification of rare coagulase-negative Staphylococcus Aureus Variants Isolated from Bovine milk samples

Staphylococci are broadly classified as coagulase-positive or-negative based on their ability to coagulate plasma. Besides the coagulase-positive Staphylococcus aureus, coagulase-negative staphylococci are also gaining significance in bovine mastitis. The precise grouping of staphylococci as coagulase-negative or-positive is an important preliminary step in establishing the aetiology of mastitis. While investigating the distribution of various species among 149 isolates obtained from bovine milk samples that were classified as coagulase-negative staphylococci based on the standard tube coagulase test, 19 isolates were identified as S. aureus by a species-specific polymerase chain reaction (PCR) for the presence of nuc, fib and 23S rRNA genes. Furthermore, characterisation revealed that all of them showed thermostable nuclease activity, but only 16 of them fermented mannitol. Only one of these was confirmed as belonging to S. aureus by phenotyping. None of the isolates except one possessed the antibiotic resistant genes mecA, aacA-Dor aph(3)-IIIa. Significantly, 14 of the isolates were positive by PCR for the coa gene. The study highlights the occurrence of rare coagulase-negative variants of S. aureus in bovine intramammary infections and the possibility of misidentification of these isolates as coagulase-negative staphylococci.