Hepatitis C genotype 4: genotypic diversity, epidemiological profile, and clinical relevance of subtypes in Saudi Arabia

Hepatitis C virus genotypes 4 [HCV-4] is the most prevalent genotype in Saudi Arabia, although it's various subtypes, mode and route of transmission remains unknown. The aim of this study was to analyze [i] the variability of the HCV-4 subtypes, the route and source of HCV transmission and [ii] the influence of HCV-4 subtypes on their therapeutic response. Sixty-four HCV-4 patients were analyzed retrospectively for the prevalence of various sub-genotypes and the possible mode of transmission, and it was correlated with their treatment response to pegylated interferon [PEG-IFN] alpha-2a and ribavirin therapy. Positive history of blood or blood products transfusion was noted in 22 patients [34%], hemodialysis in 10 patients [15.6%], surgery in 7 patients [11%], and unknown etiology in 25 patients [39%]. Prevalence of HCV-4 subtypes was 4a = 48.4% [31/64], 4d = 39% [25/64], 4n = 6.25% [4/64], and remaining combined [4m, 4l, 4r, 4o] 6.25% [4/64]. No significant correlation between subtypes and the source of transmission was recognized [P = 0.62]. Sustained virological response in all HCV-4 patients was 64% [41/64], while in each subtypes separately it was 4a 77.4% [24/31], 4d 52% [13/25], and combined [4n, 4m, 4l, 4r, 4o] 62.5% [5/8] [P = 0.046]. No obvious cause for the mode of HCV transmission was noted in majority of the patients. No significant correlation was observed between HCV-4 subtypes and the source of HCV infection. 4a and 4d subtypes were the most common in Saudi Arabia, and patients infected with 4a subtype responded significantly better to combination therapy than to 4d subtype

"Serotyping and antibiotic susceptibility of Group B streptococcal isolates from obstetric patients"

A total of 156 recent distinct isolates of Group B streptococcus [GBS] were recovered from clinical specimens of female patients at Madinah Maternity and Children Hospital and King Khalid University Hospital, Saudi Arabia. Serotyping results revealed that 96 percent of the strains were serotypable and the most frequent serotypes were III, II, and Ia which accounted for 35.26, and 15 percent strains respectively. Whereas serotypes Ib, IV, and V constituted 9, 7, and 4 percent respectively. The minimum inhibitory concentrations [MIC] of antibiotics against GBS isolates were determined by an agar dilution method. All GBS strains were susceptible to 0.125 mg/L of either penicillin, ampicillin, erythromycin, or clindamycin. Whereas at 0.06 mg/L the inhibitory effect of these antibiotics were 80, 69, 45, and 86 percent respectively. Cefoxtin, gentamicin, and tetracycline, however, showed remarkable variation in their activities. The majority of GBS strains showed intermediate susceptibility towards cefoxitin, whereas 35 and 77 percent of the isolates were resistant to gentamicin [GM] and tetracycline [Tc] respectively. The genetic basis of Tc-resistance was investigated was investigated. No plasmids were detected among the randomly selected different GBS sterotypes resistant to Tc. However, in all cases EcoRI- digested chromosomal DNA from resistant strains hybridized with the used tet-gene probe [ATCC 37234] of Kpnl/Hpal 0.39 [Kb] fragment. No differences were detected between GBS strains of various origin. No resistance to penicillin or ampicillin was found, nor was penicillinase production demonstrated. Yet tolerace to penicillin was found among GBS strains as tested by penicillinase-disk diffusion, penicillin-gradient replica plating and quantitative killing curves methods. Data of the latter method showed that 21 strains [14 percent] were tolerant to penicillin. Results suggest that penicillin tolerance is not rare among strains of GBS isolated in our hospitals and its routine testing may be warranted