Molecular Analysis and Ex Vivo Infectivity of Seronegative Occult Hepatitis C Virus: A Study in Single Haemodialysis Centre.

Background: In occult hepatitis C virus infection (OCI), hepatitis C virus ribonucleic acid (HCV RNA) is detectable in peripheral blood mononuclear cells (PBMCs) but is not evident in serum or plasma. Understanding of OCI in patients with seronegative anti-HCV antibodies is limited. Methods: In this study, six HCV isolates from haemodialysis (HD) patients with seronegative OCI were identified by molecular assays and phylogenetic analysis. The virus infectivity was assessed ex vivo using a primary naïve PBMC culture system. HCV isolates obtained from the PBMCs of 10 patients with chronic HCV infection (CCI) were characterised concurrently and used as positive controls in the cell culture. Results: Sequence analysis of the 5' untranslated region (UTR) and non-structural 5B (NS5B) region revealed that HCV genotype 3 was the most prevalent virus type in both the OCI and CCI groups. One of the occult HCV isolates was identified as a mixed type. The mean viral load (log10 RNA copies/106 cells) in the PBMC samples of the OCI group (M = 3.4, SD = 0.7) was lower than that of the CCI group (M = 4.6, SD = 1.7). Upon culture, de novo OCI-HCV replicates were detected in five out of six naïve PBMC cultures. Analysis of the replicates showed a single guanine addition in the domain III of 5'-UTR but the overall molecular structure was retained. Conclusion: Seronegative OCI is an active form of infection that replicates at a low level in PBMCs. Seronegative OCI may share the same route of transmission as CCI. The retained viral competency may have an implication for its persistence.

Streptococcus gallolyticus infection: A neglected marker for colorectal cancer?

BACKGROUND AND STUDY AIMS: Colorectal cancer (CRC) is the second most common cancer in Malaysia and mostly detected at advanced stages due to lack of awareness of CRC symptoms and signs. CRC pathogenesis is multifactorial, and there is ambiguous evidence on association of Streptococcus gallolyticus infection with CRC that needs further attention. Thus, a case-control study was conducted to determine whether S. gallolyticus infection is a predictor for CRC occurrence among patients attending Sultan Ahmad Shah Medical Centre@IIUM (SASMEC@IIUM). PATIENTS AND METHODS: A total of 33 stool samples from patients diagnosed with CRC and 80 from patients without CRC attending surgical clinic of SASMEC@IIUM were collected and analyzed with iFOBT test and PCR assay to detect S. gallolyticus. RESULTS: In this study, the proportion of S. gallolyticus infection was higher among patients with CRC (48.5%) compared with the control group (20%). Univariate analysis shows that occult blood in stool, S. gallolyticus infection and family history were significantly associated with the development of CRC (P < 0.05). Using the multivariate logistic regression model, positive stool PCR for S. gallolyticus had the lowest relative standard error and almost five times the odds of developing CRC after adjusting other factors (adjusted odds ratio = 4.7, 95% confidence interval = 1.7-12.6, relative standard error = 59.6%). CONCLUSION: This finding suggests that S. gallolyticus infection was the strongest predictor of CRC's development in our study and potentially serves as a predictive marker for early detection of disease progression.

Direct cell imprint lithography in superconductive carbon black polymer composites: process optimization, characterization and in vitro toxicity analysis.

Cell imprint lithography (CIL) or cell replication plays a vital role in fields like biomimetic smart culture substrates, bone tissue engineering, cell guiding, cell adhesion, tissue engineering, cell microenvironments, tissue microenvironments, cell research, drug delivery, diagnostics, therapeutics and many other applications. Herein we report a new formulation of superconductive carbon black photopolymer composite and its characterization towards a CIL process technique. In this article, we demonstrated an approach of using a carbon nanoparticle-polymer composite (CPC) for patterning cells. It is observed that a 0.3 wt % load of carbon nanoparticles (CNPs) in a carbon polymer mixture (CPM) was optimal for cell-imprint replica fabrication. The electrical resistance of the 3-CPC (0.3 wt %) was reduced by 68% when compared to N-CPC (0 wt %). This method successfully replicated the single cell with sub-organelle scale. The shape of microvesicles, grooves, pores, blebs or microvilli on the cellular surface was patterned clearly. This technique delivers a free-standing cell feature substrate. In vitro evaluation of the polymer demonstrated it as an ideal candidate for biomimetic biomaterial applications. This approach also finds its application in study based on morphology, especially for drug delivery applications and for investigations based on molecular pathways.

Antimicrobial Susceptibility of Klebsiella pneumoniae and Escherichia coli with Extended-Spectrum ß-lactamase associated Genes in Hospital Tengku Ampuan Afzan, Kuantan, Pahang.

BACKGROUND: To assess antimicrobial susceptibility of extended-spectrum ß-lactamase- (ESBL-) producing Klebsiella pneumoniae and Escherichia coli isolates from Hospital Tengku Ampuan Afzan (HTAA), as well as to identify ESBL genes. METHODS: Non-duplicate K. pneumoniae and E. coli isolates were recovered from various clinical samples. Isolates were screened for antimicrobial resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were subjected to phenotypic ESBL production. Detection of resistance genes was then performed using primers specific for ESBL genes (bla CTX-M, bla SHV and bla TEM). RESULTS: Piperacillin/tazobactam and carbapenems remained the active ß-lactam antibiotic against K. pneumoniae and E. coli. ESBLs were detected among 35.5% (39/110) of K. pneumoniae and 18.8% (28/149) of E. coli isolates. CTX-M ß-lactamase was detected in 90% of all ESBL-positive isolates, whereas bla SHV and bla TEM genes were found among 56% and 52% of them, respectively. Twenty-eight percent (28%) of the total ESBL-positive isolates harboured the three ESBL genes, while 50% carried two of the tested ESBL genes. CONCLUSION: ESBLs encoded by at least one ESBL genes are frequently isolated among K. pneumoniae and E. coli in HTAA. The significant proportion rate of these resistant determinants is alarming, thus monitoring their transmission and dissemination is essential to control it at an early phase.