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PubMed2006

Phylogenetic diversity of avian nephritis virus in Hungarian chicken flocks.

Avian nephritis virus (ANV) infection was detected in 4-day-old to 22-day-old chickens collected on Hungarian farms between 2002 and 2005. The animals suffered from diarrhoea, growth retardation, runting-stunting syndrome, and 2 to 6% mortality was reported. Tubulonephrosis, interstitial nephritis and uricosis (gout) was diagnosed. The presence of ANV RNA was detected in chicken carcasses using reverse transcriptase-polymerase chain reaction. The virus was demonstrated in 69% of the investigated farms. The nucleotide sequence of the amplification products (corresponding to part of the genome that encodes the GP1 protein) was determined and phylogenetic analysis was performed. The nucleotide sequences showed 76 to 86% identity to the reference strain isolated in 1976 in Japan. The constructed phlyogenetic tree indicates high diversity of the Hungarian ANV sequences, regardless of their origin and year of sample collection. Analysis of the putative amino acid sequences encoded by the partial GP1 sequences also revealed high diversity of the virus. Even samples collected at the same farm, at the same time but from different flocks, differed in nucleotide and putative amino acid sequences. The possible effects of the sequence diversity on the pathogenicity, antigenicity and diagnostics of ANV are discussed.

Animals↗
PubMed2004

Comparison of pathways controlling toxicity in the eye and brain in Drosophila models of human neurodegenerative diseases.

Most human neurodegenerative diseases have a number of common features, including adult onset, progressive degeneration of selected neuronal populations and formation of abnormal protein aggregates. Although these shared characteristics raise the possibility of conserved pathogenic mechanisms, the diverse clinical and pathological features of each disorder indicate significant differences. As a number of human neurodegenerative diseases have now been modeled in Drosophila, and genetic modifiers identified, we have been able to perform a genetic comparison of pathways controlling toxicity in these models. By directly comparing modifiers isolated in the models of polyglutamine diseases and in a Drosophila model of tauopathy, we find a final common pathway of cell death involving apoptosis. Among the polyglutamine diseases, protein folding and histone acetylation are common key mediators. In addition, two novel modifiers suggest shared pathways of toxicity among all the disorders. Cell-type specificity is a salient feature of all neurodegenerative diseases; however, most work to date in the Drosophila models have been performed in the retina. Therefore, we determined whether similar pathways of toxicity operate in neurons of the Drosophila brain. Many, but not all, retinal modifiers also modify toxicity in postmitotic neurons in the brain. Analysis of polyglutamine toxicity in the adult brain facilitated the identification of nicotinamide (vitamin B3), a vitamin with histone deacetylase inhibiting activity, as a potent suppressor of polyglutamine toxicity. These findings outline common pathways of neurotoxicity, demonstrate disease- and cell-type specific pathways and identify a common vitamin as a potential therapy in polyglutamine disorders.

Animals↗
PubMed2004

A specific genetic background is required for acquisition and expression of virulence factors in Escherichia coli.

In bacteria, the evolution of pathogenicity seems to be the result of the constant arrival of virulence factors (VFs) into the bacterial genome. However, the integration, retention, and/or expression of these factors may be the result of the interaction between the new arriving genes and the bacterial genomic background. To test this hypothesis, a phylogenetic analysis was done on a collection of 98 Escherichia coli/Shigella strains representing the pathogenic and commensal diversity of the species. The distribution of 17 VFs associated to the different E. coli pathovars was superimposed on the phylogenetic tree. Three major types of VFs can be recognized: (1) VFs that arrive and are expressed in different genetic backgrounds (such as VFs associated with the pathovars of mild chronic diarrhea: enteroaggregative, enteropathogenic, and diffusely-adhering E. coli), (2) VFs that arrive in different genetic backgrounds but are preferentially found, associated with a specific pathology, in only one particular background (such as VFs associated with extraintestinal diseases), and (3) VFs that require a particular genetic background for the arrival and expression of their virulence potential (such as VFs associated with pathovars typical of severe acute diarrhea: enterohemorragic, enterotoxigenic, and enteroinvasive E. coli strains). The possibility of a single arrival of VFs by chance, followed by a vertical transmission, was ruled out by comparing the evolutionary histories of some of these VFs to the strain phylogeny. These evidences suggest that important changes in the genome of E. coli have occurred during the diversification of the species, allowing the virulence factors associated with severe acute diarrhea to arrive in the population. Thus, the E. coli genome seems to be formed by an "ancestral" and a "derived" background, each one responsible for the acquisition and expression of different virulence factors.

Amino Acid Transport Systems, Neutral↗
PubMed1990

Pathogenicity of the enterococcus in surgical infections.

The enterococcus has been relegated to a position of unimportance in the pathogenesis of surgical infections. However the increasing prevalence and virulence of these bacteria prompt reconsideration of this view, particularly because the surgical patient has become increasingly vulnerable to infectious morbidity due to debility, immunosuppression, and therapy with increasingly potent antibiotics. The enterococcus is a versatile opportunistic nosocomial pathogen, causing such diverse infections as wound, intra-abdominal, and urinary tract infections; catheter-associated infection; suppurative thrombophlebitis; endocarditis; and pneumonia. Although surgical drainage remains the cornerstone of therapy for enterococcal infections involving a discrete focus, in the circumstances typified by the compromised surgical patient, specific antibacterial therapy directed against the enterococcus is warranted. Recent evidence indicates that parenteral antibiotic therapy for enterococcal bacteremia is mandatory and that appropriate therapy clearly reduces the number of deaths.

Cross Infection↗
PubMed1999

Nuclear rDNA phylogeny in the fungal genus Verticillium and its relationship to insect and plant virulence, extracellular proteases and carbohydrases.

Phylogenetic relationships among 18 isolates in the genus Verticillium, representing 13 species of diverse econutritional groups (pathogens of insects, plants, mushrooms, nematodes and spiders, and saprobes), were examined by using sequences from the internal transcribed spacer (ITS) and small nuclear (NS) rRNA regions. The isolates were also assessed for their abilities to infect insect larvae (Galleria mellonella) and to cause necrosis in alfalfa (Medicago sativa), and for their proteolytic, chitinolytic and pectinolytic activities. The phylogenetic data suggested that Verticillium is polyphyletic in origin and is therefore a form genus. However, the phylogenetic tree supported the plant pathogens (V. dahliae, V. albo-atrum and V. nigrescens) as a clade. The alfalfa isolate of V. albo-atrum (isolate 595) was an interesting outlier to the main body of plant pathogens as it clustered with the insect pathogen V. indicum. Strains of V. lecanii and V. indicum were able to infect insects and are present in divergent groups in the consensus tree, suggesting that the ability to infect insects may have evolved independently many times. Similarly, the nematophagous Verticillium species appear to have evolved independently along several different routes and one isolate, V. chlamydosporium, was able to infect insects. V. albo-atrum, V. nigrescens and V. dahliae all produced high levels of enzymes capable of degrading pectin, a major component of plant cell walls. The ability to excrete pectinase was a broad indicator of the ability to produce lesions on alfalfa. In the plant pathogens, the functions of a broad-spectrum protease were assumed by trypsins which degrade Bz-AA-AA-Arg-NA substrates (Bz, benzoyl; AA, various amino acids; NA, p-nitroanilide). The insect pathogens and mushroom pathogen (V. fungicola) were characterized by production of high levels of subtilisin-like proteases active against a chymotrypsin substrate (succinyl-Ala2-Pro-Phe-NA) and the inability to clear pectin. The insect and mushroom pathogens, and several nematode pathogens, were distinguishable from the plant pathogens in their ability to produce chitinases.

Animals↗
PubMed1999

Genetic and antigenic diversity of human rotaviruses: potential impact on the success of candidate vaccines.

Licensing of the first human rotavirus vaccine raises the hope of a reduction in the burden of paediatric diarrheal disease. However, the less than optimal performance of this vaccine in trials carried out in developing countries indicates that improvements in vaccine design are necessary. Analysis of the genetic and antigenic diversity of rotavirus isolates collected from various geographical locations suggests that future vaccine formulations may need to include a broader spectrum of strains. This may increase vaccine efficacy by providing comprehensive coverage against circulating viruses. Continued surveillance and genetic analysis of the rotavirus population prior to and after the introduction of routine vaccination will reveal if the diversity of this pathogen will impact on the success of vaccine programs.

Antigenic Variation↗
PubMed1995

Molecular genetics of plant disease resistance.

Plant breeders have used disease resistance genes (R genes) to control plant disease since the turn of the century. Molecular cloning of R genes that enable plants to resist a diverse range of pathogens has revealed that the proteins encoded by these genes have several features in common. These findings suggest that plants may have evolved common signal transduction mechanisms for the expression of resistance to a wide range of unrelated pathogens. Characterization of the molecular signals involved in pathogen recognition and of the molecular events that specify the expression of resistance may lead to novel strategies for plant disease control.

Amino Acid Sequence↗
PubMed2001

Complete nucleotide sequence and analysis of the locus of enterocyte Effacement from rabbit diarrheagenic Escherichia coli RDEC-1.

The pathogenicity island termed the locus of enterocyte effacement (LEE) is found in diverse attaching and effacing pathogens associated with diarrhea in humans and other animal species. To explore the relation of variation in LEE sequences to host specificity and genetic lineage, we determined the nucleotide sequence of the LEE region from a rabbit diarrheagenic Escherichia coli strain RDEC-1 (O15:H-) and compared it with those from human enteropathogenic E. coli (EPEC, O127:H6) and enterohemorrhagic E. coli (EHEC, O157:H7) strains. Differing from EPEC and EHEC LEEs, the RDEC-1 LEE is not inserted at selC and is flanked by an IS2 element and the lifA toxin gene. The RDEC-1 LEE contains a core region of 40 open reading frames, all of which are shared with the LEE of EPEC and EHEC. orf3 and the ERIC (enteric repetitive intergenic consensus) sequence present in the LEEs of EHEC and EPEC are absent from the RDEC-1 LEE. The predicted promoters of LEE1, LEE2, LEE3, tir, and LEE4 operons are highly conserved among the LEEs, although the upstream regions varied considerably for tir and the crucial LEE1 promoter, suggesting differences in regulation. Among the shared genes, high homology (>95% identity) between the RDEC-1 and the EPEC and EHEC LEEs at the predicted amino acid level was observed for the components of the type III secretion apparatus, the Ces chaperones, and the Ler regulator. In contrast, more divergence (66 to 88% identity) was observed in genes encoding proteins involved in host interaction, such as intimin (Eae) and the secreted proteins (Tir and Esps). A comparison of the highly variable genes from RDEC-1 with those from a number of attaching and effacing pathogens infecting different species and of different evolutionary lineages was performed. Although RDEC-1 diverges from some human-infecting EPEC and EHEC, most of the variation observed appeared to be due to evolutionary lineage rather than host specificity. Therefore, much of the observed hypervariability in genes involved in pathogenesis may not represent specific adaptation to different host species.

Amino Acid Sequence↗
PubMed2000

Analysis of the SOS response in Salmonella enterica serovar typhimurium using RNA fingerprinting by arbitrarily primed PCR.

We report an analysis of a sample of the SOS response of Salmonella enterica serovar Typhimurium using the differential display of RNA fingerprinting gels of arbitrarily primed PCR products. The SOS response was induced by the addition of mitomycin C to an exponentially growing culture of serovar Typhimurium, and the RNA population was sampled during the following 2 h. These experiments revealed 21 differentially expressed PCR fragments representing mRNA transcripts. These 21 fragments correspond to 20 distinct genes. All of these transcripts were positively regulated, with the observed induction starting 10 to 120 min after addition of mitomycin C. Fifteen of the 21 transcripts have no homologue in the public sequence data banks and are therefore classified as novel. The remaining six transcripts corresponded to the recE, stpA, sulA, and umuC genes, and to a gene encoding a hypothetical protein in the Escherichia coli lysU-cadA intergenic region; the recE gene was represented twice by nonoverlapping fragments. In order to determine if the induction of these 20 transcripts constitutes part of a classical SOS regulon, we assessed the induction of these genes in a recA mutant. With one exception, the increased expression of these genes in response to mitomycin C was dependent on the presence of a functional recA allele. The exception was fivefold induced in the absence of a functional RecA protein, suggesting another layer of regulation in response to mitomycin C, in addition to the RecA-LexA pathway of SOS induction. Our data reveal several genes belonging to operons known to be directly involved in pathogenesis. In addition, we have found several phage-like sequences, some of which may be landmarks of pathogenicity determinants. On the basis of these observations, we propose that the general use of DNA-damaging agents coupled with differential gene expression analysis may be a useful and easy method for identifying pathogenicity determinants in diverse organisms.

Bacterial Proteins↗
PubMed2002

Molecular genetic analysis of ICEF, an integrative conjugal element that is present as a repetitive sequence in the chromosome of Mycoplasma fermentans PG18.

Mycoplasma genomes contain compact gene sets that approach the minimal complement necessary for life and reflect multiple evolutionary instances of genomic reduction. Lateral gene transfer may play a critical role in shaping the mobile gene pool in these organisms, yet complex mobile elements have not been reported within this genus. We describe here a large ( approximately 23-kb) genetic element with unique features that is present in four copies in the Mycoplasma fermentans PG18 chromosome, accounting for approximately 8% of the genome. These novel elements, designated ICEF (integrative conjugal elements of M. fermentans), resemble conjugative, self-transmissible integrating elements (constins) in that circular, nonreplicative extrachromosomal forms occur in which the left and right termini of the integrated element are juxtaposed and separated by a coupling sequence derived from direct repeats flanking chromosomal copies of ICEF as a result of target site duplication. ICEF contain multiple similarly oriented open reading frames (ORFs), of which some have homology to products of known conjugation genes but others have no known counterparts. Surprisingly, unlike other constins, ICEF lack homologs of known integrases, transposases, or recombinases, suggesting that a novel enzyme may be employed for integration-excision. Skewed distribution and varied sites of chromosomal integration among M. fermentans isolates suggest a role for ICEF in promoting genomic and phenotypic variation in this species. Identification of homologs of terminal ICEF ORFs in two additional mycoplasma species indicates that ICEF is the prototype member of a family of ICE-related elements that may be widespread among pathogenic mycoplasmas infecting diverse vertebrate hosts.

Chromosomes, Bacterial↗
PubMed2003

Genetic polymorphism and molecular epidemiology of Leishmania (Viannia) braziliensis from different hosts and geographic areas in Brazil.

Numerical zymotaxonomy and variability of the internal transcribed spacers (ITS) between the small and large subunits of the rRNA genes were used to examine strain variation and relationships in natural populations of Leishmania (Viannia) braziliensis. A total of 101 strains from distinct hosts and Brazilian geographic regions were assigned to 15 zymodemes clustered in two major genetic groups. The great number of isolates (48.5%) placed in zymodeme IOC/Z-27 were collected on the Atlantic coast. The high molecular diversity found in populations in the Amazon Basin was related to the great number of sandfly vector(s) in that region. The results of the restriction fragment length polymorphism analysis of the ITS depicted considerable intraspecific variation. Genotypic groups A, B, and C contained 39, 40, and 22 isolates, which were divided into 16, 10, and 15 genotypes, respectively. The genetic polymorphism observed demonstrates the degree of diversity of L. (V.) braziliensis strains from different regions where they are endemic. The results reinforce the clonal theory for Leishmania parasites showing the genetic diversity of this pathogen and an association of L. (V.) braziliensis genotypes with specific transmission cycles, probably reflecting an adaptation of different clones to the vector species involved.

Animals↗
PubMed1974

Secondary respiratory infection in hospital patients: effect of antimicrobial agents and environment.

A prospective study of 358 medical and 234 postoperative patients with clinical evidence of secondary chest infection showed that previous administration of antimicrobial agents greatly reduced the chance of obtaining a clear-cut laboratory report. In patients with radiographical evidence of pneumonia this led to a fourfold decrease in the overall rate of isolation of potential pathogens. Furthermore, 81 diverse "coliforms" were isolated from 258 medical and surgical patients who had received previous antimicrobial therapy while only four coliforms (all Escherichia coli) were isolated from 334 untreated patients. Thus the general hospital environment on its own seemed to have a negligible influence in promoting the growth of coliform flora in sputum. Any unique effect of underlying disease in this regard was masked by that of previous therapy. Finally, the results raised the possibility that previous antimicrobial therapy might have increased the risk of secondary pneumonia in hospital patients.

Anti-Bacterial Agents↗
PubMed1999

Cellulose acetate phthalate (CAP): an 'inactive' pharmaceutical excipient with antiviral activity in the mouse model of genital herpesvirus infection.

The spread of sexually transmitted infections caused by herpes simplex virus type 2 (HSV-2) has continued unabated. At least 20% of the United States population has been infected with HSV-2 and there is a high probability of further virus transmission by asymptomatic carriers. Given the absence of effective vaccines, this indicates the need to develop prophylactic measures such as topical microbicides that have antiviral activity. Recent studies indicate that cellulose acetate phthalate (CAP), an inactive pharmaceutical excipient commonly used in the production of enteric tablets and capsules, is a broad specificity microbicide against diverse sexually transmitted pathogens. When appropriately formulated in micronized form, it inactivates various viruses, including HSV-2, in vitro. Here we show that CAP inhibits HSV-2 infection in the mouse model of genital HSV-2 infection. Pretreatment with micronized CAP formulated in a glycerol-based cream with colloidal silicone dioxide significantly reduced the proportion of HSV-2-infected mice (10% virus shedding, 0-5% lesion development and 0% fatality for CAP as compared to 84% shedding, 63% lesion development and 63% fatality in saline-treated mice). These differences were significant (P < or = 0.0002 by the test of equality of two proportions). Virus titres in the minority of mice that developed infection were similar to those in untreated mice. HSV-2 infection was not inhibited by treatment with CAP formulated with other inactive ingredients (for example povidone plus crosprovidone) instead of silicone dioxide, presumably reflecting CAP complexation/inactivation. These data suggest that properly formulated, CAP may be an efficacious agent for preventing vaginal transmission of genital herpesvirus infections.

Animals↗
PubMed2006

Helicobacter pylori genotypes identified in gastric biopsy specimens from Jordanian patients.

BACKGROUND: The genetic diversity of Helicobacter pylori can be analyzed at two different levels: the genomic variation between strains originating from different individuals, and the variation in bacterial populations within an individual host. We reported for the first time the H. pylori genotypes in Jordanian patients with gastrointestinal diseases. METHODS: Upper endoscopy was performed on 250 patients with symptoms of gastrointestinal diseases. Multiple gastric biopsy specimens were taken from the antrum. All the biopsies were tested by PCR for the H. pylori virulence genes vacA, cagA, and iceA, and 151 were tested by histology. RESULTS: The biopsies positive for H. pylori by PCR were 110/250 (44%), and by histology 117/151 (77.5%), and these results were highly associated (P < 0.02). Analyses of virulence genes revealed that iceA2 (73.6%) was the predominant genotype, the vacAs2 allele was more frequently identified than the vacAs1 allele, while the cagA genotype was low (26.4%). The presence of certain genotypes might be associated with each other, but the presence of certain genotypes was not significantly associated with the age, or gender of the patient. CONCLUSION: The results illustrate the geographic nature of the genetic diversity of H. pylori, as the identified genotypes are similar to those reported in neighboring countries. This study provides a baseline data of H. pylori genotypes identified in gastric biopsy specimens from Jordan, serving as a powerful epidemiological tool for prospective investigations to better understand the genetic diversity of this pathogen.

Adolescent↗
PubMed2005

Vasculature deprivation--induced osteonecrosis of the rat femoral head as a model for therapeutic trials.

EXPERIMENTAL OSTEONECROSIS: The authors' experience with experimentally produced femoral capital osteonecrosis in rats is reviewed: incising the periosteum at the base of the neck of the femur and cutting the ligamentum teres leads to coagulation necrosis of the epiphysis. The necrotic debris is substituted by fibrous tissue concomitantly with resorption of the dead soft and hard tissues by macrophages and osteoclasts, respectively. Progressively, the formerly necrotic epiphysis is repopulated by hematopoietic-fatty tissue, and replaced by architecturally abnormal and biomechanically weak bone. The femoral heads lose their smooth-surfaced hemispherical shape in the wake of the load transfer through the hip joint such that, together with regressive changes of the joint cartilage and inflammatory-hyperplastic changes of the articular membrane, an osteoarthritis-like disorder ensues. THERAPEUTIC CHOICES: Diverse therapeutic options are studied to satisfy the different opinions concerning the significance of diverse etiological and pathogenic mechanisms: 1. Exposure to hyperbaric oxygen. 2. Exposure to hyperbaric oxygen and non-weight bearing on the operated hip. 3. Medication with enoxaparin. 4. Reduction of intraosseous hypertension, putting to use a procedure aimed at core decompression, namely drilling a channel through the femoral head. 5. Medication with vascular endothelial growth factor with a view to accelerating revascularization. 6. Medication with zoledronic acid to decrease osteoclastic productivity such that the remodeling of the femoral head is slowed. Glucocorticoid-related osteonecrosis appears to be apoptosis-related, thus differing from the vessel-deprivation-induced tissue coagulation found in idiopathic osteonecrosis. The quantities of TNF-alpha, RANK-ligand and osteoprotegerin are raised in glucocorticoid-treated osteoblasts so that the differentiation of osteoclasts is blocked. Moreover, the osteoblasts and osteocytes of the femoral cortex mostly undergo apoptosis after a lengthy period of glucocorticoid medication.

Animals↗
PubMed2026

P2X7 Receptor in Rare Diseases: Shared Molecular Mechanisms and Therapeutic Implications.

Rare diseases (RDs) are individually uncommon but collectively affect a large global population, and the vast majority still lack effective disease-modifying therapies. With advances in genomics and data-sharing platforms, research has increasingly shifted from a single-disease perspective to the search for convergent molecular pathways that might be shared across clinically distinct entities. In this context, the purinergic P2X7 receptor (P2X7R) has emerged as a putative "shared molecular platform" due to its central role in inflammation amplification, cell death and immune regulation. P2X7R is an ATP-gated ion channel with unique structural and functional features: under high extracellular ATP, it not only forms a non-selective cation channel but can also dilate into a "large pore" permeable to macromolecules, thereby triggering Ca2+overload, NLRP3 inflammasome assembly, reactive oxygen species (ROS) production and apoptotic/necrotic-like cell death. This review briefly outlines the epidemiology of RDs and the structural-functional characteristics of P2X7R, then systematically summarizes current evidence linking P2X7R to multiple rare diseases, including Charcot-Marie-Tooth disease, Guillain-Barr&#xe9; syndrome, amyotrophic lateral sclerosis, Huntington's disease, multiple sclerosis, and selected inflammatory and metabolic RDs (CAPS, familial Mediterranean fever, Systemic sclerosis, Dravet syndrome and Gaucher disease). By comparing P2X7R expression and functional alterations, downstream signaling pathways and pharmacological data from animal models across these conditions, we propose that a P2X7R-dependent network centered on a "Ca2+-NLRP3-inflammation/cell death axis" may constitute a common pathogenic backbone for diverse RDs. At the same time, disease-specific spatiotemporal expression patterns of P2X7R in central vs peripheral nervous systems and in immune vs target organ cells confer marked context dependence and "double-edged sword" properties. Finally, we discuss opportunities and challenges for P2X7R-targeted strategies, including the impact of disease stage and sex differences on therapeutic efficacy, and key bottlenecks in translating preclinical findings into clinical benefit. A deeper understanding of both shared and disease-specific roles of P2X7R may provide a conceptual framework and therapeutic entry point for precision stratification and multi-target interventions in rare diseases.

P2X7 receptor↗
PubMed1999

Hepatitis C genotypes and subtypes in Saudi Arabia.

Hepatitis C virus (HCV) genotypes are diverse geographically. Infectivity, pathogenicity, and sustained response to treatment may be influenced by HCV genotypes/subtypes. This study examined the relative distribution of hepatitis C genotypes and subtypes among isolates from 84 individuals with chronic active hepatitis (CAH), 39 haemodialysis patients, and 31 intravenous drug addicts, of Saudi Arabian origin. Reverse transcription-polymerase chain reaction (RT-PCR) using specific primers from the 5'-UTR was performed and amplified products were genotyped/subtyped using a commercial reverse phase hybridisation technique (Innolipa HCV 11, Innogenetics, Belgium). Seventy-four percent of the CAH patients were found to be genotype 4 (4c/4d: 33%; 4h: 14%; 4e: 7%; 4: 20%) but other subtypes such as 1b: 14%, 2b: 4%, 3a: 5%, 5a: 1%, and 6a: 1%, were also detected. A history of blood transfusion was disclosed in only 10% of the CAH group. The pattern among haemodialysis patients was as follows: genotype 4: 49% (4h: 13%; 4: 36% ); 1a: 33%, 1: 3%; 1b: 10%; and 5a: 5%. The intravenous drug addict group showed 39% subtype 1b, but other subtypes such as 9% for 1a; 3% for 2a; 36% for 4; 3% for 5a; and 9% for 3a were seen. It is concluded that genotype 4 is predominant among our HCV isolates from CAH patients but subtype 1a and 1b have emerged among our haemodialysis and intravenous drug addict cases, respectively. A significant relationship between the viral genotype and the source of infection has emerged among Saudi groups at high risk for hepatitis C virus.

Adult↗