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Molecular characterization of coagulase-negative staphylococcus and biofilmassociated genes in S. Capitis / Aziyah Abdul Aziz
No full textThe coagulase-negative Staphylococcus (CoNS) is a group of bacteria that are gaining prominence as emerging pathogens of hospital-acquired infections. One such species is S. capitis, which is now the major cause of bloodstream infection especially in neonatal intensive units. The major virulence factor of S. capitis appears to be its ability to form a biofilm structure. A total of 200 local clinical isolates of CoNS was obtained from the Hospital Tuanku Ampuan Rahimah, Klang in between December 2010 to May 2011.Nine species of CoNS were identified with S. epidermidis, S. haemolyticus, S. hominis and S. capitis being the most prevalent strains. Identification of the isolates by biochemical tests using the Microgen Staph ID kit was less than 50% accurate while identification via the sodA gene sequence provided better discrimination and accuracy.The ERIC-PCR fingerprinting was then used to genotype the CoNS strains and the Discriminative Index (D) was calculated. At D = 0.949, ERIC-PCR can be used with confidence to discriminate between the S. hominis strains. However, low discriminative power (D < 0.9) was observed for S. capitis, S. epidermidis and S. haemolyticus implying that ERIC-PCR fingerprinting is not sufficient to genotype these strains. A multiplex PCR method was successfully developed to probe for the presence of icaABCD operon in a majority of the bacterial strains. At 88%, S. capitis showed the highest ability to form
biofilm with a large percentage of-these forming dense biofilm structures while the icaABCD operon was found to be present in all of the strains. Biofilm formation was however less frequent in other species, e.g. 39.2% in S. epidermidis, 16.7% in S. hominis and 3.3% in S. haemolyticus. Antimicrobial susceptibility test showed that for S. capitis, the formation of biofilm significantly increased the resistance of the biofilm cells to six types of antibiotics, similar to that reported for S. epidermidis. However, except for the case of ciprofloxacin, the thickness of biofilm did not appear to have any effect on the antibiotic resistance of the cells. Strain S. capitis B102 was selected for screening of novel biofilm-associated genes due to its ability to consistently form a very thick biofilm. Attempts to generate biofilm-defective mutants by transposon-mediated mutagenesis using the bursa aurealis system was however unsuccessful. Comparative genomics of B102 and three other S. capitis strains P27 (a non-biofilm former), B63 (moderate biofilm) and B145 (very strong biofilm) revealed that the S. capitis genome was dynamically shaped by horizontal gene transfer (HGT) via prophages, Staphylococcal Chromosome Cassettes (SCC) and plasmids. Some mobile genetic elements (MGE) present only in B102 and B145 are found to carry genes implicated in biofilm formation e.g. the Atl autolysin. By comparing the SNP profiles in strains with different biofilm phenotype, a list of seven candidate biofilm-associated genes was obtained. The ability of S. capitis to acquire additional genetic elements via HGT, and its propensity to form robust biofilm which enhances its antibiotic resistance, points to the possibility of this organism evolving into a significant pathogen
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Rain / Aziyah Abdul-Aziz and Nurul Nadhirah Foong
Get PDFThe Academy of Language Studies, Universiti Teknologi MARA (UiTM) Cawangan Kedah is thrilled to announce the release of the fourth edition of its e-magazine, The Epitome. This publication represents our steady dedication to cultivating creativity in language and literature. The primary objective of THE EPITOME is to offer a platform for writers, educators, scholars, poets, and researchers can come together to exchange their ideas, discoveries, expertise, and narratives. Our special focus revolves around an array of creative writing genres, encompassing playwriting, short stories, songs, speeches, memoirs, literary journalism, humour writing, lyric essays, innovative essays, and personal essays, with a goal to embrace diverse linguistic expressions, with content available in four languages: English, Bahasa Melayu, Mandarin, and Arabic
Antibiotic resistance properties of Staphylococcus epidermidis isolated from hospitals in Selangor / Asmirah Ahmadunissah, Shafiq Aazmi and Aziyah Abdul-Aziz
Get PDFA total of 89 Coagulase-Negative Staphylococci (CoNS) samples used in this study were collected from clinical hospitals in Selangor. These isolates were grown on Mannitol Salt Agar (MSA) to screen for pink colonies that do not reduce mannitol which is a characteristic of CoNS. The purified isolates were subjected to standard biochemical tests which include Gram stain, slide coagulase, catalase, and urease test. Identification of Staphylococcus epidermidis was performed using the tuf gene sequencing method which confirmed the species at a total of 60 out of the 89 isolates. When tested against several antibiotics, 41.7% of the isolates were found to be resistant to cefoxitin followed by erythromycin (38.3 %), gentamicin (16.7 %), rifampin (16.7 %), clindamycin (15.0 %), and ciprofloxacin (8.3 %). In contrast, all of the S. epidermidis isolates were sensitive against linezolid. This supports the use of linezolid in the current treatment of S. epidermidis infections. Hence, the speciation of S. epidermidis and its antibiotic resistance patterns may further establish their role as a significant pathogen and help in initiating proper antimicrobial therapy
SCCmec typing of clinical isolates Staphylococcus haemolyticus / Farhan Haziq Azharollah and Aziyah Abdul-Aziz
Get PDFA total number of 38 clinical strains of Staphylococcus haemolyticus originally obtained from Hospital Tuanku Ampuan Rahimah, Klang Selangor, were used in this study. The antimicrobial susceptibility of these nosocomial pathogens was tested against penicillin and cefoxitin. Except for one strain (B200) which was sensitive, the rest of the isolates were resistant to penicillin. Similarly, only one strain (F4) was sensitive against oxacillin while the rest were resistant. For cefoxitin, 34 or 89.5% of the isolates were resistant to this antibiotic and classified as Methicillin resistance Staphylococcus haemolyticus (MRSH). Amplification of the mecA gene showed among the MRSH strains 19 or 55.9% harbour the mecA gene but 15 or 44.1% were found negative for this gene. This could be due to the mec gene complex which does not only consist of the mecA gene but could also harbour other classes of mec genes such as mecB, mecC, mecD or mecE. However, one of the Methicillin-sensitive Staphylococcus haemolyticus (MSSH) strains susceptible against cefoxitin was also found to harbour the mecA gene. All the 20 isolates positive for mecA gene were further subjected to Staphylococcal Cassette Chromosome mec (SCCmec) type I, II, III, IV and V. The results showed that two or 10.0% of the strains (B14 and R27) expressed SCCmec type II while only one isolate (P29) expressed SCCmec type III. For the remaining 17 isolates, SCCmec typing was not detected suggesting that these isolates do not harbour SCCmec I, IV or V. Hence, there is a possibility that these isolates carry other types of SCCmec
The characterization of mecA Gene and SCCmec typing in clinical samples of MRSA / Siti Aisya Aswani and Aziyah Abdul-Aziz
Get PDFMRSA is a major pathogen worldwide and its infections are associated with increased morbidity and mortality, in comparison with other S. aureus infections. The study was designed to characterize the mecA gene and staphylococcal cassette chromosome (SCCmec) in methicillin resistance S. aureus (MRSA). A total of 20 presumptive S. aureus strains were collected from one of the teaching hospitals in Selangor. Using standard biochemical tests, all the isolates were verified as S. aureus. When tested against cefoxitin, 80% of the isolates were confirmed as MRSA. All the MRSA isolates were further subjected to polymerase chain reaction (PCR) to detect the presence of mecA gene. Nine out of the 16 MRSA isolates (56%) were mecA positive, whereas the remaining four were mecA negative. The 16 MRSA with positive mecA gene were further subjected to SCCmec typing of type I, II, III, IV and V. The most frequent SCCmec types were type III (56%) followed by type II (33%), and type IV (11%). None of the isolates were of SCCmec type I or V. Our study indicates that SCCmec type III is predominant among the isolates which is in agreement with other studies conducted on clinical strains of MRSA
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The characterization of mecA gene and SCCmec typing in clinical samples of MRSA / Siti Aisya Aswani and Aziyah Abdul-Aziz
Get PDFMRSA is a major pathogen worldwide and its infections are associated with increased morbidity and
mortality, in comparison with other S. aureus infections. The study was designed to characterize the mecA
gene and staphylococcal cassette chromosome (SCCmec) in methicillin resistance S. aureus (MRSA). A
total of 20 presumptive S. aureus strains were collected from one of the teaching hospitals in Selangor.
Using standard biochemical tests, all the isolates were verified as S. aureus. When tested against
cefoxitin, 80% of the isolates were confirmed as MRSA. All the MRSA isolates were further subjected to
polymerase chain reaction (PCR) to detect the presence of mecA gene. Nine out of the 16 MRSA isolates
(56%) were mecA positive, whereas the remaining four were mecA negative. The 16 MRSA with positive
mecA gene were further subjected to SCCmec typing of type I, II, III, IV and V. The most frequent
SCCmec types were type III (56%) followed by type II (33%), and type IV (11%). None of the isolates
were of SCCmec type I or V. Our study indicates that SCCmec type III is predominant among the isolates
which is in agreement with other studies conducted on clinical strains of MRSA
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