ABSTRACT
Background: Onychomycosis is a common nail disorder caused mostly by Trichophytonrubrum and Trichophytonmentagrophytes. As other conditions may resemble onychomycosis, the accurate detection and identification of the causal agent is mandatory. Conventional methods for detecting fungi in nail specimens are either nonspecific or insensitive and time consuming, especially in cases of previous antifungal therapy. Recently, PCR based assays have been introduced to improve onychomycosis diagnosis
Objectives: Evaluation of the performance of a multiplex PCR for detecting demartophytes compared with the results of the conventional culture technique in patients with clinically suspected onychomycosis
Methodology: A multiplex PCR-based method was evaluated using 50 nail specimens collected from onychomycosis patients. After a rapid DNA extraction method, the multiplex PCR was performed using three sets of primers aimed at detecting dermatophytes generally, T. rubrum and T mentagrophytes. Amplicon analysis was made using agarose gel electrophoresis. PCR results were compared with those of the direct microscopy and culture of the nails
Results: Among the 50 patients with onycomycosis, 70% [35/50] were positive for fungal elements microscopic examination. Positive fungal cultures were detected in 60% [30/50]. The results of PCR showed that 58% [29/50] were positive by pan Derm PCR. Dermatophyte positive by PCR were 23 T. rubrum, 4 T. mentagrophytes and 2 other dermatophytes, while 20/50 [40%] of them yielded growth of dermatophytes in culture, 17 T. rubrum and 3 T. mentagrophytes. In ten samples where culture yielded growth of non-dermatophytemoulds and yeasts, PCR was positive for T. rubrum [one] while PCR was negative in 9 non-dermatophytemould and yeast positive cultures
Conclusion: Multiplex-PCR method applied directly on nail specimens could be a promising diagnostic tool for the management of the patients with suspected onychomycosis
ABSTRACT
Occult hepatitis B virus infection [OBI] has been reported among patients with chronic hepatitis C virus [HCV] infection and hepatocellular carcinoma [HCC]. This study aimed to evaluate the prevalence of OBI in chronic hepatitis C patients with and without hepatocellular carcinoma. A total of 40 chronic hepatitis C patients who were negative for HBsAg, were enrolled into the study. They were classified into two groups: Group I which included 20 patients with chronic hepatitis C only whereas Group II included 20 patients with chronic hepatitis C and HCC. Detection of HBV DNA was done by nested-PCR using two sets of primers specific for surface and X viral genomes in serum and liver tissue of patients. Genotyping system based on PCR using type-specific primers was done for HBV-DNA positive intrahepatic samples. OBI was detected in the liver tissue in 23/40 [57.5%] of chronic HCV infected patients, 18 [78.3%] of whom belonged to group II, conferring a 90% prevalence of this group. In serum, HBV-DNA was detected in 9/40 patients [22.5%], 7 [77.8%] of whom belonged to group II. Among the 23 positive intrahepatic HBV-DNA samples studied, HBV-genotype D [34.8%] and B [26.1%] were more predominant, whereas HBV-genotype C [13.1%] and A [8.7%] infections were the least observed, respectively; mixed genotypes were detected in 17.4% [n = 4], 3 of them were with HBV-genotype D and B, and 1 was with HBV-genotype C and A. In conclusion OBI is a fact in our community; it was detected in liver tissue of chronic HCV-infected patients, especially in cases of chronic HCC. In addition, OBI might be related to severity of necroinflammatory activity and fibrosis. Large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population. Also, detection of intrahepatic HBV-DNA is more useful in diagnosis of OBI
ABSTRACT
Neonatal sepsis is a significant cause of morbidity and mortality in neonates. The gold standard for detecting bacterial sepsis is blood culture. However, it has low sensitivity and a reporting delay of approximately 48-72 h. Molecular assays for the detection of bacterial DNA represent possible new diagnostic tools for early identification of a bacterial cause. This study aimed at comparing a broad range 16S rDNA PCR to conventional blood culture for detecting bacterial DNA in blood samples from neonates with suspected sepsis. Fifty neonates with suspected sepsis, admitted at Neonatal Intensive Care Unit of Ain Shams University Hospitals, were included in this study. From each neonate, a minimum of 2-3 ml blood was collected by standard sterile procedures, 1 ml for conventional blood culture and 1-2 ml EDTA blood for PCR. The isolated microorganisms were identified by conventional microbiological methods. Thirty neonates [60%] gave positive blood culture results. The most frequently isolated microorganisms were Staphylococcus aureus [n = 17, 56.7%], followed by Coagulase negative Staphylococci [n = 7, 23.3%], Escherichia coli [n = 4, 13.3%], and Candida spp. [n = 2, 6.7%]. Twenty-eight [56%] neonates gave positive bacterial blood culture while 35 [70%] neonates gave positive PCR results. Considering the blood culture as the gold standard in diagnosis of bacterial neonatal sepsis, the sensitivity, specificity, positive predictive value and negative predictive value of PCR in detecting bacteremia relative to blood cultures were 20/28 [71.42%], 7/22 [31.81%], 20/35 [57.14%] and 7/15 [46.66%], respectively. In conclusion, PCR approach appears to be a relatively easy, reliable and valuable complementary method for diagnosis of neonatal sepsis for samples obtained during antimicrobial treatment especially when routine cultures remain negative. Staphylococci spp. has played an important role in causing neonatal sepsis. So, implementation of simple infection control measures such as hand washing, barrier nursing and promotion of clean deliveries should be considered to reduce neonatal sepsis