Coagulase Test Research Articles

Intestinal Bacterial Colonization in the First 2 Weeks of Life of Nigerian Neonates Using Standard Culture Methods.

The pattern and timing of development of intestinal microflora in Nigerian infants have been scarcely researched. This study was carried out to investigate the bacteria flora in the rectum of healthy neonates in Ibadan, Nigeria. In this hospital-based longitudinal study, rectal swabs of 70 neonates were taken within 6-12 h of birth (day 1) and subsequently on days 3, 9, and 14. Information collected included maternal sociodemographic characteristics, antibiotic use for the neonates, and type of feeding during the first 14 days of life. Identification and speciation of gram-negative isolates were done using the Analytical Profile Index 20E® and 20NE® as appropriate. Gram-positive bacteria were identified biochemically using the catalase and coagulase tests. Data were analyzed using descriptive statistics and Chi-square at p = 0.05. Majority (92.9%) of the neonates were delivered vaginally with a median gestational age of 38 weeks (range = 34-42). On the first day of life, Escherichia coli was isolated more frequently from the rectal swabs of preterm (50.0%) than term (23.1%) neonates (p = 0.031). On day 3 of life, coagulase-negative staphylococcus was the most frequently isolated bacteria from the rectal swabs of nonasphyxiated (64.4%) compared with asphyxiated (27.3%) neonates' rectal swabs (p = 0.042). Staphylococcus aureus was the most frequently isolated bacteria from the rectal swabs of nonexclusively breastfed (66.7%) than exclusively breastfed (21.3%) neonates on day 14 (p = 0.004). Staphylococcus aureus and Escherichia coli were the predominant isolates from the rectum of Nigerian neonates, and these isolates were influenced by breastfeeding and mild-moderate asphyxia. In all, bacterial diversity in the rectum increased as the neonates got older.

Bacteria in chicken rolls sold by fast food restaurant and their public health significance

This study determined bacterial quality of chicken rolls sold in a fast food restaurant at Bangladesh Agricultural University (BAU) campus. Fifteen chicken rolls (ten premicrowaved and five post-microwaved) were collected. Samples were inoculated into selective media, Eosin Methylene Blue (EMB) agar, Salmonella Shigella (SS) agar, Thiosulphate Citrate Bile Salts Sucrose (TCBS) agar and Mannitol Salt (MS) agar. The total viable count (TVC) and total Staphylococcal count (TSC) of pre-microwaved samples were 4.4 log CFU/g and 4.2 log CFU/g, respectively. In post-microwaved samples, the TVC and TSC were 2.7 log CFU/g and 2.6 log CFU/g, respectively. Microwave treatment significantly reduced the TVC and TSC in the chicken rolls (P<0.05). Bacteria were recovered only from samples inoculated onto MS agar. Colonies on MS agar were characteristics of Staphylococcus spp, confirmed by sugar fermentation, catalase and coagulase tests and polymerase chain reaction (PCR) assay. This study recorded coagulase negative staphylococcus (CNS) resistant to three antibiotics, ampicillin, cephalexin and vancomycin. It is suggested that chicken rolls sold in the fast food restaurant contaminated with resistant CNS might pose a public health hazard.Bangl. vet. 2015. Vol. 32, No. 1, 13-18

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolated from clinical samples at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.

BackgroundStaphylococcus aureus particularly MRSA strains are one of the major causes of community and hospital acquired bacterial infections. They are also becoming increasingly multi-drug resistant and have recently developed resistance to vancomycin, which has been used successfully to treat MRSA for many years. In-vitro determination of drug resistance patterns of S. aureus is critical for the selection of effective drugs for the treatment of staphylococci infections.The main aim of this study was to determine the prevalence of methicillin resistant S. aureus strains from different clinical specimens from patients referred for routine culture and sensitivity testing.MethodA cross sectional study was conducted among 1360 participants at Yekatit 12 Hospital Medical College in Ethiopia from September 2013 to April 2014. Clinical samples from various anatomical sites of study participants were cultured on blood agar and mannitol salt agar and identified to be S. aureus by using catalase, coagulase and DNAse tests. S. aureus isolates then were screened for MRSA using 30 μg cefoxitin disc and other 11 antimicrobial drugs by disc diffusion procedure, and agar dilution and E tests for vancomycin. All S. aureus isolates examined for beta-lactamase production by employing nitrocefin. Data were analyzed using SPSS version 20 software and logistic regressions were applied to assess any association between dependent and independent variables.ResultsOf 1360 clinical specimens analyzed S. aureus was recovered from (194, 14.3 %). Rate of isolation of S. aureus with regard to clinical specimens was the highest in pus (118, 55.4 %).No S. aureus was isolated from CSF and urethral discharge. Out of 194 S. aureus isolates, (34, 17.5 %) were found out to be MRSA and the remaining (160, 82.5 %) were MSSA. Ninety eight (50.5 %) S. aureus were multi drug resistant and the highest isolates were resistant to penicillin (187, 96.4 %) and least resistant for clindamycin (23, 11.9 %) and vancomycin (10, 5.1 %). MRSA strains were 100 % resistant to penicillin G, erythromycin, trimethoprim-sulfamethoxazole and least resistant to vancomycin (10, 29.4 %). Out of 194 S. aureus isolates (153, 79.0 %) were beta-lactamase producers.ConclusionIn this study S. aureus isolates exhibited very high degree of resistance to different antibiotics. The isolates were also multidrug resistant to several combinations of the tested antibiotics. The emergence of vancomycin resistant S. aureus highlights the value of prudent prescribing of antibiotics and avoiding their irrational use.

Methicillin-resistant Staphylococcus aureus Nasal Carriage Among Patients Admitted at Shaqra General Hospital in Saudi Arabia

Methicillin-resistant Staphylococcus aureus (MRSA) have been causing increasing problems in hospitals and nursing homes worldwide. Limited number of studies in Saudi Arabia has attempted to investigate infection and risk factors associated with nosocomial acquired MRSA. The present study was undertaken to determine the occurrence, prevalence, antibiotic susceptibility pattern and genetic characteristics of MRSA among admitted cases at Shaqra General Hospital (Saudi Arabia). This study was conducted from October, 2014 to March, 2015. Nasal swabs were taken from 220 patients (105 males and 115 females) admitted at Shaqra General Hospital. The isolates were identified as S. aureus based on morphology, Gram stain, catalase test, coagulase test and mannitol salt agar fermentation. Antibiotic susceptibility testing of MRSA was performed with standard disk diffusion method. All methicillin-resistant isolates were examined for the existence of the mecA gene by PCR technique. Of the 220 patients, 90 (40.91%) were found to be nasal carriers of S. aureus. Among these 90 S. aureus isolates, 48 (21.82%) were MRSA. A statistically significant difference was only found for antibiotics usage between those with and without MRSA colonization. Antibiotic susceptibility pattern of isolated MRSA showed high susceptibility to vancomycin, linezolid, rifampicin, teicoplanin, complete resistance to penicillin, ampicillin, oxacillin and cefoxitin and intermediate resistance to amikacin, ciprofloxacin, teicoplanin, tetracycline and vancomycin. A high prevalence of multidrug-resistant MRSA nasal carriage was found. The identification of MRSA carriers is a step towards establishing a control policy for MRSA and helps to identify measures needed to reduce colonization pressure.

Detection of Streptococcus pneumoniae and Moraxella catarrhalis in patients with paranasal chronic sinusitis by polymerase chain reaction method

BackgroundSinusitis is a complex involvement of the upper respiratory system by bacteria, viruses, fungi, or other allergens. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the dominant bacterial microorganisms involved in acute sinusitis, whereas in chronic sinusitis, Staphylococcus aureus and some anaerobic bacteria are the prevailing pathogens. Appropriate antibiotic treatment requires sinusitis bacteriology assessment. The aim of this study was to isolate bacteria in clinical samples from patients with chronic sinusitis. MethodsA total of 55 samples were collected from patients with chronic sinusitis undergoing surgery at Imam Khomeini Hospital in Ahvaz, Iran. Samples were cultured in conventional medium, and for each culture, Gram staining, catalase, coagulase, oxidase, and DNAse tests were performed and isolates were stored for polymerase chain reaction analysis. ResultsTwenty-three isolates were obtained from five patients, including S. aureus (23.6%), Rhizomucor (1.8%), and Escherichia (1.8%) by the culture method and M. catarrhalis (3.6%) and S. Pneumoniae (7.2%) by the polymerase chain reaction method. Compared with acute sinusitis, the microbiology of chronic sinusitis remains controversial. Results are affected by many factors, including diversity of molecular and culture methods, sterilization of sampling area, sample transfer to laboratory, use of antibiotics prior to surgery, and nasal polyps. ConclusionIn Iran, the causative agents of chronic sinusitis are similar to those in other countries. Compared with other bacteria, S. aureus was observed more often in asthmatic patients with sinusitis.

Identification of Candida and Trichosporon species by oxidase and coagulase test.

30May 2016 Identification of Candida and Trichosporon species by oxidase and coagulase test. Afreen , Bhattacharyya S , Sengupta A , Sarfraz A , Kumar D , Kumar R , Kumar A and Singh S. Department of Botany, Patna University, Patna, Bihar, India. Department of Microbiology, AIIMS Patna, Bihar, India.

Effects of High Customer Patronage on the Indoor Air Quality of Restaurants in Lokoja Metropolis and Its Public Health Impact

Indoor air is an essential environment for healthy living and it can become a dominant source of contaminants when it is incorporated with complex mixture of biological and non-biological particles as a result of human activities. The effect of high customer patronage on the indoor air quality of restaurants in Lokoja metropolis and its public health impacts was investigated. Twelve restaurants were sampled; seven from Lokoja-Abuja highway and five from IBB way using standard microbiological assays and biochemical test such as citrate utilization test, urease test, catalase test, indole test, oxidase test and coagulase test. Bacteria isolated from the sampled restaurants were Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Streptococcus pyogenes, Escherichia coli and Micrococcus luteus. The airborne fungal isolates were Aspergillus niger, Aspergilus flavus, Penicillium chrysogenum, Rhizopus stolinifer, Fusarium oxysporum and Clasdosporium fulvum. Restaurant B on the Lokoja-Abuja high way has the highest bacterial count of 400cfu per minute of exposure while restaurant Y on the IBB way has the lowest bacterial count of 25cfu per minute of exposure. Restaurant B has the highest fungal count of 6.0 cfu per minute of exposure while restaurant Z has the lowest count of 1.5 cfu per minute exposure. Escherichia coli was the mostly distributed bacteria while Streptococcus pyogenes was the least distributed. Rhizopus stolinifer was the highest fungal distributed and Clasdosporium fulvum the least. Human activities contribute to the indoor air quality of these restaurants and this could pose a danger to customers especially the immunocompromised customers which will have a concomitant effect on the patronage of the restaurants. Proper sanitation, personal hygiene and good ventilation system is recommended to avoid contamination of food and spread of diseases.

Isolation, identification and characterization of bacterial flora from the respiratory tract of apparently healthy sheep

Sheep is the common name for a group of grazing mammals that may be either wild or domesticated; the domesticated varieties are amongst the most widely distributed types of domestic animal, found in nearly all countries. Bangladesh is a densely populated developing country and its economy is primarily based on agriculture. The current study was designed for isolation, identification and characterization of bacterial flora from the upper respiratory tract of sheep. Thirty (30) apparently healthy sheep were selected at the adjacent areas of Bangladesh Agricultural University (BAU) for this experiment. Swab samples were collected from nasal swabs (10), lung swabs (10) and tracheal swabs (10). All samples were subjected into inoculated on to bacteriological media (nutrient broth, nutrient agar, Salmonella-Shigella agar, MacConkey agar, blood agar, brilliant green agar). Furthermore, all of the bacterial isolates were characterized by Gram’s staining, biochemical tests (sugar fermentation tests, catalase test, coagulase test, indole test, MR-VP test), antibiotics sensitivity tests and pathogenicity tests. None of the isolated Bacillus, E. coli and Staphylococcus spp. was found to be pathogenic. Isolated Pasteurella spp. were found to be pathogenic as observed in different experimental models and showed a degree of variation in antibiotic drug sensitivity test. Ciprofloxacillin was sensitive to all of the isolated bacteria. Through the bacteria that were isolated from various organs of apparently healthy sheep is normal micro flora, however these may act as primary pathogen and may produce diseases when the sheep are immunologically suppressed due to severe stress conditions.Asian J. Med. Biol. Res. December 2015, 1(3): 677-685

Staphylococcus aureus carriage rates and antibiotic resistance patterns in patients with acne vulgaris

Overuse of antibiotics has led to the development of antibiotic-resistant strains of Staphylococcus aureus, which are occurring more frequently within the community. We sought to determine whether long-term antibiotic therapy for acne alter the carriage rate and antibiotic resistance profiles of S aureus. This was a prospective, cross-sectional, quasiexperimental study. Samples of anterior nares were obtained from dermatology patients given a diagnosis of acne vulgaris (n = 263) who were treated with antibiotics (n = 142) or who were not treated with antibiotics (n = 121). Specimens were tested for the presence of S aureus by growth on mannitol salt agar and then isolated on 5% sheep blood agar. Identification was confirmed based on colonial morphology, Gram stain, catalase, and coagulase testing. Antibiotic susceptibility testing was performed using the VITEK 2 system (bioMerieux, Marcy-l'Étoile, France). The S aureus carriage rate was significantly lower in patients with acne treated with antibiotics (6.3%) compared with those not treated with antibiotics (15.7%; P = .016). The percentage of S aureus isolates resistant to 1 or more antibiotics did not significantly differ between the 2 groups (P = .434). Cross-sectional study, patient compliance, and effects of prior acne treatments are limitations. Treatment of patients with acne using antibiotics decreases the S aureus carriage rate but does not significantly alter the antibiotic resistance rates.

Phenotypic Characteristics of Vancomycin-Non-Susceptible Staphylococcus aureus.

Background:Staphylococcus aureus, with reduced vancomycin susceptibility, is probably under the regulation of several genes and various express phenotypes.Objectives:This study aimed to investigate the phenotypic differences between vancomycin-susceptible S. aureus (VSSA), vancomycin-intermediate S. aureus (VISA), and heterogeneous VISA (hVISA) isolates.Materials and Methods:A total of 130 methicillin-resistant S. aureus (MRSA) isolates were studied, including 49 VSSA, 28 hVISA, and 5 VISA isolates from blood cultures and 48 isolates (two VSSA, six hVISA, and 40 VISA) derived in vitro (laboratory-induced/sub-passaged). Their phenotypes were examined using a coagulase tube test, colony spreading on soft agar, and urease activity. The SCCmec and agr typing were performed using multiplex PCR.Results:Most of the MRSA isolates were SCCmec III-agr I (84.5%), followed by SCCmec II-agr II (11.8%). The average plasma coagulation time of vancomycin-non-susceptible isolates was longer than that of the susceptible isolates (12 vs. 2.6 hours). Four hVISA (P = 0.023) and nine VISA (P < 0.001) isolates yielded a negative coagulase test after 24-hour incubation. The percentage of VSSA isolates showing non-spreading colonies (accessory gene regulator (agr) dysfunction) was significantly lower than in the VISA group (P = 0.013), but no significant difference was found between VSSA and hVISA. The VISA group showed higher urease activity than that of the VSSA and hVISA groups (P = 0.002).Conclusions:There were diverse phenotypic changes among vancomycin-non-susceptible S. aureus isolates. This may be due to the variety of related regulatory systems. The diversity of phenotypic expression may result in its misidentification in routine laboratory checks.

Occurrence of Staphylococcal Subclinical Mastitis in Cattle in and Around Jabalpur (M.P.)

Mastitis, caused by multifactorial etiopathological factors, is one of the costliest disease of dairy animals across the globe. The study was conducted for a period of more than 1 year i.e. from February 2015 to February 2016. For the epidemiological study 550 lactating cattle were screened by modified California mastitis test (MCMT). Clinical examination of animals and their udder/milk and phenotypic characterization of Staphylococcus spp. was carried out. The overall occurrence of Staphylococcal SCM was reported to be 16.36% (90/550) animal wise and 6.07% (127/2092) quarter wise as identified on the basis of colony morphology, characteristic colour changes on Mannitol salt agar, positive catalase test, haemolysis pattern on blood agar and DNase activity on DNase agar. Thirty one isolates were found coagulase positive as revealed by coagulase test and 96 were found to be coagulase negative Staphylococci (CNS). The occurrence was highest in right hind quarter (8.77%), in age group of 5–7 years (23.77%). in 5th parity (25.64%) and in early lactation (31.64%) period. Occurrence was also reported higher in monsoon and post monsoon.

Coagulase negative staphylococci as a pathogen from wound infections in a Tertiary care Hospital

Introduction: Wound infections are a common type of infections that may contribute to longer hospital stay. Most of these infections are superficial and readily treated with a regimen of local care and antibiotics. Determination of the etiologic agent is vital in the final choice of antibiotics. CoNS are previously considered as contaminants and non-pathogenic have been identified as the etiological agents in most hospital acquired infections. These were considered clinically significant when isolated in pure culture from infected sites and in repeated samples. Material and Methods: Retrospective statistical analysis from Jan – Dec 2015. 283 swabs from wound infections were processed by following standard operative procedures. All samples were subjected to direct microscopy (Gram staining) and culture. Culture positive samples were processed by doing Gram staing and Coagulase test. Coagulase negative staphylococcal isolates (CoNS) were subjected for antibiotic susceptibility testing. Results: Of total 283 samples, 159 were culture positive (56.18%). Among 159 isolates 55 were Coagulase negative staphylococci (34.59%). The isolates showed high susceptibility to vancomycin (85.45%). But 80% of CoNS were MRCoNS. Susceptibility to gentamycin was high (69.09%) followed by Amoxiclav (amoxicillin and clavulanic acid - 58.18%), ciprofloxacin (52.72%), ceftriaxone (38.18%), cefaperazone and penicillin (36.36%) and cotrimaxazole (27.27%). Conclusions: 1. CoNS should be considered as an emerging pathogen in wound infections. 2. CoNS is becoming resistant to commonly used antibiotics. 3. CoNS is developing resistance even to vancomycin. Key words: Antibiotic susceptibility testing, Methicillin resistance, Pathogen, Wound infections

Prevalence and Antibiotic Susceptibility Patterns of Methicillin Resistant Staphylococcus Aureus in Patients Attending the Laquintinie Hospital Douala, Cameroon

Methicillin Resistant Staphylococcus aureus (MRSA) is a major health problem worldwide. Diseases caused by these microorganisms most often are difficult to treat consequently, present with severe outcomes. Despite the increase association of MRSA in most hospital acquired infections, surveillance systems to control the spread of these infections are lacking especially in the developing countries. The present study is part of a major study developed to trail the incidence of multidrug resistant pathogens in clinical settings using available resources, with the aim to gather relevant data for the management and control of nosocomial infections. The specific objective of the current study is therefore to determine the prevalence and antimicrobial susceptibility of MRSA isolates from one of the largest hospitals in the country. This was a hospital based cross sectional study involving 114 participants, conducted between March and June 2016. Various clinical specimens were inoculated on to blood agar and mannitol salt agar and incubated at 35-37°C aerobically for 18-24 hours for the isolation of S. aureus. Isolates were identified using the catalase and coagulase tests. Sensitivity testing was done using the Kirby Bauer disk diffusion method. Data were analysed using SPSS version 20.0. Out of 114 samples analysed, S. aureus was isolated from 33 (28.95%) while MRSA was detected in 15 (13.16%). Antimicrobial susceptibility testing revealed high resistance (80-100%) to penicillins and no resistance to amikacin, lincomycin and ofloxacin. Multidrug resistance to at least three antibiotics was also observed among MRSA isolates. MRSA and multidrug resistant S. aureus are common in the study site. Therefore, there is a need for the improvement of surveillance systems to monitor and curb the spread of these resistant pathogens.

Prevalence and phenotypic detection of methicillin resistance Staphylococcus aureus between ruminants butchered for humanoid intake and animal handlers in Maiduguri, Nigeria

Objective: The objectives of this study was to investigate phenotypically the prevalence of Staphylococcus aureus and Methicillin Resistance S. aureus (MRSA) in ruminants and animal handlers in Maiduguri, Nigeria. Materials and methods: A total of 937 samples (900 nasal and skin swabs of cattle and 37 humans samples) were collected in Maiduguri metropolis. The samples were inoculated onto mannitol salt agar (MSA) and blood agar, and the cultrue plates were incubated at 37 o C for 24 h. The S. aureus colonies showing golden yellow color on MSA were primarily identified as S. aureus , which were then subjected for catalase and coagulase tests. All S. aureus were finally screened for the presence of MRSA on oxalate resistant screening agar (ORSAB) medium. Antimicrobial susceptibility of the MRSA were measured by disc diffusion method. Results: The overall prevalence of S. aureus was 44.3% (n=414/937). The MRSA could be detected in 12.1% (n=113/937) samples. Considerign different species, S. aureus could be isolated from 137 (45.6%), 148 (49.3%) and 119 (39.7%), 11 (29.7%) cattle, sheep, goat and humans, respectively. In ruminants, 27.7% (n-83/300) bulls were positive for S. aureus . Similarly, 10.7% (n=32/300) and 22.3% (n=67/300) were positive for S. aureus in rams and bucks, respectively. On the other hand, 18% (n=54/300), 38.7% (n=116/300) and 17.3% (n=52/300) samples from cows, ewes and does were positive for S. aureus . The highest MRSA could be isolated from ewes (9.3%; n=28/300) follwed by bulls (7%; n=21/300) and bucks (6.7%; n=20/300). In humans, 13.5% (n=5/37) samples were positive for MRSA. Conclusion: S. aureus and MRSA infections in ruminants and animal handlers are documented in this study. The MRSA may exert public health threat to humans. http://doi.org/10.5455/javar.2016.c145

SEQUENCING AND PHYLOGENETIC CHARACTERIZATION OF S. AUREUS THERMONUCLEASE GENE

Mastitis is considered the most predominant production infectious disease in dairy industry all over the world including Egypt, The difficulty of mastitis occurs due to its chronic nature of the disease, extremely economic losses, extensively spread all over the year and intense decrease in the milk production. Staphylococcus aureus is one of the most common bacterial agents causing mastitis and having public health importance. A total of 248 milk samples were collected from different dairy farms, 77 samples from mastitic milk, 171 from apparently normal milk. 24 samples were positive for S. aureus by applying coagulase test. This study is concerned with the detection of thermonuclease (NUC gene) of S. aureus through PCR reaction, sequencing and phylogenetic analysis. Sequence alignments and phylogenetic analysis revealed high level of similarities between the different alleles isolated from different samples. Genotyping and sequencing analysis of NUC gene is a good tool to understand the relationships and differences between different isolates of S. aureus causing mastitis in dairy farms.

Sequence Analysis of Pathogenic Staphylococcus Aureus Isolated from Different Sources

Staphylococcus aureus is an adaptable, opportunistic pathogen with abilities to persist and multiply in a variety of environments and cause a wide spectrum of diseases in both humans and animals. Atotal of 144 samples from different sources (human,large animal,poultry and rabbit) were examined bacteriologically and biochemically. The results in this study revealed that out of total 97 isolates suspected to be Staphylococci, 42 isolates were positive for tube coagulase test (TCT) at a percentage of 43.2%. The antimicrobial sensitivity pattern of Staphylococcus aureus against 14 commertially available antibiotic discs showed 100% resistance to Kanamycin followed by Ampicillin (93.33%), Erythromycin (86.67%), Chloramphenicol (73.33%), Norfloxacin (73.33%), Cloxacillin (66.67%),Oxytetracycline (60.00%), Ciprofloxacin (60.00%), Sulphamethoxazol (46.67%), Gentamicin (40.00%), Amoxicillin (26.67%), Enrofloxacin (26.67%), Oxacillin (13.33%) and The least was observed with Cephalotin (6.67%). All 15 clinical isolates (4from human-6from large animal-3from poultry-2 from rabbit) tested by multiplex PCR were positive for clfB (100%). The other genes were heterogeneously detected:13 (86.66%) isolates(4human-5large animal-3poultry-1rabbit) of the strains were positive for clfA,7 (46.66%) isolates(3human-2large animal-1poultry-1rabbit) were positive for cna ,5 (33.33%) isolates(2human-2large animal-1poultry-0 rabbit) were positive for bbp.

Isolation, Identification and Antibiogram ofStaphylococcus aureusIsolated from Bovine Mastitis

In the present study, out of 255 milk samples (185 from subclinical and 70 from clinical cases) screened for Staphylococcus aureus, 53 isolates were obtained giving an overall incidence of 20.78%. The incidence of S. aureus from subclinical mastitis was 8.11% (15/185) and from clinical mastitis was 54.29% (38/70). Species-wise incidence was 30.77% (16/52) in buffaloes and 18.23% (37/203) in cows. All 53 isolates were identified on the basis of colony characters on nutrient agar, staining and biochemical characters namely catalase production, oxidise test, maltose fermentation test and ohosphatase test. Out of 53 isolates, 49 (92.45%) isolates showed coagulase production in tube coagulase test. Number of isolates showing alpha, beta, gamma and alpha-beta haemolysin production were 18 (33.96%), 26 (49.06%), 4 (7.55%) and 5 (9.43%) on sheep blood agar, respectively. All the 53 S. aureus isolates were confirmed genotypically by 23S rRNA ribotyping in which a species-specific amplicon of 1, 250 bp was obtained. Antibiotic sensitivity patterns of all these 53 S. aureus isolates revealed that the isolates were most sensitive to gentamicin (94.34%), whereas penicillin (94.34%) and ampicillin (86.79%) were highly resistant to S. aureus.

Comparison between Staphylococcus aureus, strains isolated from medical students in pre-clinical formation and clinical training

OBJECTIVE: To establish the differences between Staphylococcus aureus isolates from medical students in pre-clinical and clinical training and identify the level of susceptibility to methicillin, vancomycin and alternative antibiotics.MATERIALS AND METHODS: A cross-sectional observational design with non-random sampling was used in medical students during pre-clinical and clinical training. Samples were taken from nasal swabs and cultured on blood agar. For beta-hemolytic gram-positive cocci, catalase and coagulase tests were performed and then cultured on mannitol salt agar. Susceptibility to cefoxitin, oxacillin, linezolid, clindamycin and trimethoprim sulfamethoxazole was assessed by using the Kirby-Bauer technique, and for vancomycin, an E-test was performed (Biomerieux®).RESULTS: 51 strains of S. aureus from nasal swabs were isolated from 112 medical students. 68.6% were identifi ed as methicillinsensitive (MSSA) and 31.4% as methicillin-resistant (MRSA). Four MRSA strains showed vancomycin intermediate (VISA 4-8 μg/mL) profile, 41% of MSSA isolates was resistant to clindamycin, 31% to linezolid and 23.5% to trimethoprim sulfamethoxazole.DISCUSSION: MSSA, MRSA and VISA strains are present in nostrils of our medical students, with MRSA showing high resistance levels (&gt;50%) to clindamycin, TMP-SMX and linezolid, and MSSA levels up to 40%. These findings reiterate the need to accomplish good nasal and hands hygiene in order to minimize the spread of S. aureus in community and healthcare facilities.

Analysis of causative agents of urinary tract infections in children and their antibiotic sensitivity pattern: A hospital based study

Introduction: Urinary tract infections (UTIs) are an important cause of morbidity and mortality in children. Objective: To determine the common bacterial pathogens causing UTI in children less than 12 years old and their antimicrobial susceptibility patterns at the Colombo South Teaching Hospital, Sri Lanka. Method: A prospective study was done by analyzing records of urine samples received at the Department of Microbiology, Colombo South Teaching Hospital, from 1 st May 2011 to 30 th April 2012. Urine samples were inoculated on Cystine Lactose Electrolyte Deficient agar, according to standard operating procedures. The isolates were initially identified by Gram staining and colony characteristics. Gram positive organisms were further identified by catalase, coagulase and bile-aesculin tests. Lactose fermentation or non-lactose fermentation (NLF) of Gram negative organisms was recorded. The NLF isolates were further identified by oxidase, urease and Kleigler Iron Agar tests. Antibiotic susceptibility tests were carried out using the Stokes method. Results: A total of 2620 urine samples was analyzed. Of the 426 (16.3%) pure growths, Gram negative isolates of bacteriuria (>10 5 colony forming units/ml of urine) and Gram positive isolates of bacteriuria (>10 4 colony forming units/ml of urine) were found in 264 (62%) and 56 (13.1%) patients respectively. The female: male ratio of the total positive samples was 2.1:1. LF and NLF Coliforms (excluding Proteus , Providencia , and Morganella spp.) were isolated in 142 (33.3%) and 68 (16%) samples respectively. Proteus spp. were isolated in 43 (10.1%) samples 38 (88.4%) of which were identified in males. The sensitivity of LF Coliforms to nitrofurantoin, cephalexin and ampicillin was 83.9%, 57.4% and 11.3% respectively. The sensitivity of NLF Coliforms to nitrofurantoin, cephalexin and ampicillin was 85.3%, 36.8% and 7.4% respectively. Conclusions: Enterobacteriaceae were the predominant pathogens causing UTI in our population and showed high resistance against am­picillin and cephalexin. Proteus infections were predominant in males. Sri Lanka Journal of Child Health , 2015; 44 (4): 197-201

Nasal Carriage of Staphylococcus aureus among Paramedical Students in Alexandria and Evaluation of Dry Spot Staphytect Latex Kit as a Rapid Screening Method for Staphylococcus aureus

Background: Staphylococcus aureus ( S. aureus) is a common cause of nosocomial and community acquired infections worldwide. Nasal carriage of S. aureus acts as an endogenous reservoir for clinical infections in the colonized individual and also as a source of cross-colonization for community spread. Infections caused by S. aureus range clinically from minor skin infections to severe life threatening infections; with mortality rates ranging from 6 to 40 %.Treatment of staphylococcal infections has now become more challenging with emergence of methicillin resistant S. aureus (MRSA) strains; which are often also multidrug-resistant. Objectives: The present study was conducted to screen for the prevalence rate of nasal carriage of S. aureus among paramedical students studying at the Faculty of Allied Medical Sciences, Pharos University, Alexandria, Egypt. The study also aimed at studying the validity of Dry Spot Staphytect Latex Kit as a rapid screening test for identification of S. aureus. Methods: Nasal swabs were collected from 100 volunteer students over a period of three months (February-April 2015). Swabs were cultured both on blood agar and mannitol salt agar and all isolates that were confirmed microscopically and biochemically as S. aureus were tested for antibiotic sensitivity using modified Kirby Bauer technique. Dry Spot Staphytect Latex Kit was evaluated as a rapid method for identification of S. aureus, setting the positive result of tube coagulase test as a gold standard. Results: The nasal carriage rate of S. aureus detected was 34%, 18 % of which were MRSA strains. The highest level of sensitivity to antibiotics among S. aureus isolates was recorded for vancomycin and mupirocin, (97.1%) each. Regarding MRSA strains, 100% were sensitive to mupirocin and 100% were resistant to oxacillin. Dry Spot Staphytect Latex Kit had a sensitivity of 97.06 %, a specificity of 96.97 %, a positive predictive value of 94.29 %, a negative predictive value of 98.46 % and an accuracy of 97 % in rapid identification of S. aureus. Conclusion: Paramedical university students are a high risk group for nasal carriage of S. aureus and MRSA. Dry Spot Staphytect latex test is recommended for use as an efficient rapid, sensitive, specific and accurate screening test for S. aureus and MRSA. Key words: S. aureus , MRSA, nasal carriage, paramedical students, Dry Spot Staphytect Latex Kit