- Volume 63, Issue 5, 2014
Volume 63, Issue 5, 2014
- Review
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Detection of potential microbial antigens by immuno-PCR (PCR-amplified immunoassay)
More LessImmuno-PCR (PCR-amplified immunoassay; I-PCR) is a novel ultrasensitive method combining the versatility of ELISA with the sensitivity of nucleic acid amplification of PCR. The enormous exponential amplification power of PCR in an I-PCR assay leads to at least a 102–104-fold increase in sensitivity compared with an analogous ELISA. I-PCR has been used to detect many biological molecules such as proto-oncogenes, toxins, cytokines, hormones, and biomarkers for autoimmune and Alzheimer’s diseases, as well as microbial antigens and antibodies, and it can be adapted as a novel diagnostic tool for various infectious and non-infectious diseases. Quantitative real-time I-PCR has the potential to become the most analytically sensitive method for the detection of proteins. The sensitivity and specificity of a real-time I-PCR assay can be enhanced further with the use of magnetic beads and nanoparticles. This review is primarily focused on the detection of potential viral, bacterial and parasitic antigens by I-PCR assay, thus enabling their application for immunological research and for early diagnosis of infectious diseases.
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- Pathogenicity and virulence
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Analysis of gene expression changes in Trichophyton rubrum after skin interaction
More LessTrichophyton rubrum, an anthropophilic and cosmopolitan fungus, is the most common agent of superficial mycoses. In this study, T. rubrum infection was modelled by adding human skin sections to a limited medium containing glucose and cDNA microarrays were used to monitor T. rubrum gene expression patterns on a global level. We observed that exposure to human skin resulted in upregulation of the expression levels of T. rubrum genes related to many cellular and biological processes, including transcription and translation, metabolism and secondary transport, the stress response, and signalling pathways. These results provide a reference set of T. rubrum genes whose expression patterns change upon infection and reveal previously unknown genes that most likely correspond to proteins that should be considered as virulence factor candidates and potential new drug targets for T. rubrum infection.
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- Diagnostics, typing and identification
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A prediction model for real-time PCR results in blood samples from febrile patients with suspected sepsis
Sepsis, a systemic, deleterious host response to infection that leads to organ dysfunction, is a potentially deadly condition needing prompt identification of the causative organisms and early appropriate antimicrobial therapy. Among non-culture-based diagnostic methods, SeptiFast (SF) can be employed to speed bacterial and fungal DNA detection, but it suffers from poor sensitivity and high cost. The aim of the present study, performed in 285 febrile patients, was to develop a prediction model to restrict the SF assay to clinical cases with a high probability of positive SF results. The prevalence of SF results positive for a pathogen was 17.2 %. Independent predictors of positive results were: blood sampling within 12 h after the onset of fever [odds ratio (OR) 20.03; 95 % confidence interval (CI) 6.87–58.38; P<0.0001]; ≥0.5 ng serum procalcitonin (PCT) ml−1 (OR 18.52; 95 % CI 5.12–67.02; P<0.0001); body temperature ≥38 °C (OR 3.78; 95 % CI 1.39–10.25; P = 0.009); ≤3 g serum albumin dl−1 (OR 3.40; 95 % CI 1.27–9.08; P = 0.014); and ≥13 000 white blood cells mm−3 (OR 2.75; 95 % CI 1.09–7.69; P = 0.05). The model showed good calibration (Hosmer–Lemeshow chi-squared 1.61; P = 0.978). Area under the receiving operating characteristic curve was 0.944 (95 % CI 0.914–0.973; P<0.0001). These results suggest that a prediction model based on PCT and a few other routinely available laboratory and clinical variables could be of help in selecting patients with a high probability of SF-positive results.
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A PCR-RFLP assay for the detection and differentiation of Campylobacter jejuni, C. coli, C. fetus, C. hyointestinalis, C. lari, C. helveticus and C. upsaliensis
Although Campylobacter jejuni and Campylobacter coli are the most common bacterial causes of human gastrointestinal diseases, other Campylobacter species are also involved in human and animal infections. In this study, we developed a cytolethal distending toxin (cdt) gene-based PCR-RFLP assay for the detection and differentiation of C. jejuni, C. coli, C. fetus, C. hyointestinalis, C. lari, C. helveticus and C. upsaliensis. Previously designed common primers, which can amplify the cdtB gene of C. jejuni, C. coli and C. fetus, were used for detecting seven Campylobacter species and differentiating between them by restriction digestion. The PCR-RFLP assay was validated with 277 strains, including 35 C. jejuni, 19 C. coli, 20 C. fetus, 24 C. hyointestinalis, 13 C. lari, 2 C. helveticus, 22 C. upsaliensis, 3 other Campylobacter spp. and 17 other species associated with human diseases. Sensitivity and specificity of the PCR-RFLP assay were 100 % except for C. hyointestinalis (88 % sensitivity). Furthermore, the PCR-RFLP assay successfully detected and differentiated C. jejuni, C. coli and C. fetus in clinical and animal samples. The results indicate that the PCR-RFLP assay is useful for the detection and differentiation of seven Campylobacter species important for human and animal diseases.
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Development of a PCR-restriction fragment length polymorphism assay for detection and subtyping of cholix toxin variant genes of Vibrio cholerae
Cholix toxin (ChxA) is an exotoxin reported in Vibrio cholerae non-O1/non-O139. Apart from its prototype (ChxA I) we have recently identified two novel variants of this toxin, ChxA II and ChxA III. Our previous investigations indicated that the first two variants may instigate extra-intestinal infections and ChxA II can be more lethal than ChxA I in mice. However, all three cholix toxins (ChxA I to III) failed to show any enterotoxicity in rabbit ileal loops. In this study we developed a PCR-restriction fragment length polymorphism (RFLP) assay to differentiate all three chxA variants to further understand the importance of each subtype. By using 53 V. cholerae non-O1/non-O139 strains harbouring chxA genes, which were previously categorized by sequencing, and various other strains as negative controls, the PCR-RFLP assay showed 100 % typability and specificity. Furthermore, when applied to differentiate additional V. cholerae strains, which were also screened for the chxA gene by colony hybridization, this assay identified chxA I and chxA II genes among 18.5 % and 4.5 % of non-O1/non-O139 strains (n = 178), respectively. One non-O1/non-O139 strain was untypable due to the insertion of an IS911-like element. Interestingly, the chxA I gene was detected in 10 out of 137 cholera toxin gene-negative V. cholerae O1 strains. These results suggest that the PCR-RFLP assay developed in this study can be a rapid and simple method to differentiate the chxA subtypes.
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Geographical and genospecies distribution of Borrelia burgdorferi sensu lato DNA detected in humans in the USA
More LessThe present study investigated the cause of illness in human patients primarily in the southern USA with suspected Lyme disease based on erythema migrans-like skin lesions and/or symptoms consistent with early localized or late disseminated Lyme borreliosis. The study also included some patients from other states throughout the USA. Several PCR assays specific for either members of the genus Borrelia or only for Lyme group Borrelia spp. (Borrelia burgdorferi sensu lato), and DNA sequence analysis, were used to identify Borrelia spp. DNA in blood and skin biopsy samples from human patients. B. burgdorferi sensu lato DNA was found in both blood and skin biopsy samples from patients residing in the southern states and elsewhere in the USA, but no evidence of DNA from other Borrelia spp. was detected. Based on phylogenetic analysis of partial flagellin (flaB) gene sequences, strains that clustered separately with B. burgdorferi sensu stricto, Borrelia americana or Borrelia andersonii were associated with Lyme disease-like signs and symptoms in patients from the southern states, as well as from some other areas of the country. Strains most similar to B. burgdorferi sensu stricto and B. americana were found most commonly and appeared to be widely distributed among patients residing throughout the USA. The study findings suggest that human cases of Lyme disease in the southern USA may be more common than previously recognized and may also be caused by more than one species of B. burgdorferi sensu lato. This study provides further evidence that B. burgdorferi sensu stricto is not the only species associated with signs and/or symptoms consistent with Lyme borreliosis in the USA.
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- Antimicrobial agents and chemotherapy
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In vitro and in vivo effects of beneficial vaginal lactobacilli on pathogens responsible for urogenital tract infections
The aim of this work was to evaluate the effects of beneficial human vaginal lactobacilli (Lb) on urogenital pathogens through in vitro and in vivo experiments. Co-aggregative and antimicrobial properties between five vaginal Lb strains and urogenital pathogens or potential pathogens (Streptococcus agalactiae, Staphylococcus aureus and Candida albicans strains) were assayed. Also, associative cultures of Lb strains and S. agalactiae were performed and bacterial growth, pH, lactic acid and hydrogen peroxide (H2O2) were determined at different times. Based on the results obtained, the in vivo studies were assayed in mice with Lactobacillus gasseri CRL 1509 or Lactobacillus salivarius CRL 1328 inoculated intravaginally (i.v.) and then challenged i.v. with S. agalactiae. Results were analysed by ANOVA (repeated measures and general linear models). Most of the Lb strains increased the percentage of aggregation of S. agalactiae strains. Only one strain (Lactobacillus reuteri CRL 1324) positively affected the aggregation of S. aureus and none increased the aggregation of C. albicans. The inhibition of the growth of S. agalactiae strains by production of organic acids by lactobacilli was evidenced. The Lb–S. agalactiae co-cultures showed a significant inhibition of the pathogen after 4 h and 8 h of incubation. Parallel increases in lactic acid and H2O2 levels were observed. However, in the experimental murine model, no significant differences were obtained in the number of streptococci recovered from the vaginal tract of control mice and those inoculated with Lb. In conclusion, vaginal Lb exhibited in vitro co-aggregative and antimicrobial effects on S. agalactiae strains, suggesting that they could be promising candidates for protection against S. agalactiae challenge. However, as these effects were not evidenced in the murine model used, further animal studies under different experimental conditions should be conducted to evaluate the preventive effect of Lb against challenge with S. agalactiae.
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A novel nerolidol-rich essential oil from Piper claussenianum modulates Candida albicans biofilm
Candidiasis is a major opportunistic fungal infection in humans, and its incidence has increased steadily over the last two decades. Candida albicans, the main species of the genus, has a large arsenal of virulence attributes that contribute to successful infections, such as dimorphism and biofilm formation. The adverse effects of eukaryotic antimicrobial therapies associated with an increase in resistance to the compounds presently available have boosted efforts to improve the therapeutic arsenal against candidiasis with a newer and cheaper range of drugs. In this study, a novel nerolidol-rich essential oil (EO) derived from Piper claussenianum (Miq.) C. DC., Piperaceae, was tested on the growth, transition (yeast to hyphae), formation and stability of biofilms produced by C. albicans. Both inflorescence and leaf EOs were evaluated and revealed MIC values ranging from 0.04 to 0.1 % and 0.2 to 1.26 %, respectively. Furthermore, leaf EO managed to downregulate the yeast-to-hyphae transition by 81 %, as well as reducing biofilm formation by about 30 and 50 % after incubation for 24 and 48 h, respectively. The EO was also able to reduce the viability of pre-formed biofilm by 63.9 %. Finally, the association between the leaf EO and fluconazole was evaluated and revealed an interesting synergistic effect. Taken together, these results demonstrate that this novel compound could be a promising agent and could reinforce the arsenal of therapeutic alternatives for the treatment of candidiasis. Furthermore, it may represent a novel and natural source of nerolidol, which could be of interest pharmaceutically.
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Resistotype of Helicobacter pylori isolates: the impact on eradication outcome
More LessAntibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6 % of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2 and 1.9 % of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.
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- Epidemiology
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Nosocomial spread of meticillin-resistant Staphylococcus aureus with β-lactam-inducible arbekacin resistance
A meticillin-resistant Staphylococcus aureus (MRSA) strain with additional β-lactam-inducible aminoglycoside resistance was previously reported by a group at the Kitasato University in Japan. In addition to gentamicin, the ‘Kitasato strain’ was resistant to arbekacin (ABK), which is primarily used as an anti-MRSA aminoglycoside. No further studies regarding the spread of MRSA strains with the newly identified resistance mechanism have been reported to date. To obtain epidemiological data on MRSA strains with the antagonistic resistance and to analyse their genetic features, we examined the emergence of β-lactam-inducible ABK-resistant MRSA strains at our university hospital using longitudinal analysis. Among the 396 isolates, 35 (8.8 %) were found to be ABK-resistant MRSA strains (the resistance being induced by β-lactams). Moreover, based on the pulsed-field gel electrophoresis profiles, the clonality of those MRSA strains changed at different time periods. In the Kitasato strain, the antagonistic mechanism was clearly demonstrated by the integration of transposable elements; a Tn4001-IS257 hybrid structure that contained an aminoglycoside resistance gene cointegrated into a region downstream of the β-lactamase gene. In most of the MRSA strains detected in our study, the antagonistic interaction was explained by the same mechanism as that found in the Kitasato strain. Interestingly, sequence analysis showed that all of our strains carried IS257 insertion sites which were different from those of the Kitasato strain. This study shows that MRSA strains with the additional antagonistic resistance are not uncommon and have been increasingly disseminating in clinical settings.
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Molecular detection and nucleotide sequence analysis of a new Aichi virus closely related to canine kobuvirus in sewage samples
Between 2001 and 2005, 207 raw sewage samples were collected at the inflow of a sewage treatment plant in Aichi Prefecture, Japan. Of the 207 sewage samples, 137 (66.2 %) were found to be positive for amplification of Aichi virus (AiV) nucleotide using reverse transcription (RT)-PCR with 10 forward and 10 reverse primers in the 3D region corresponding to the nucleotide sequence of all kobuviruses. AiV genotype A sequences were detected in all 137 samples. New sequences of AiV were detected in nine samples, exhibiting 83 % similarity with AiV A846/88, but 95 % similarity with canine kobuvirus (CKV) US-PC0082 in this region. The nucleotide sequences from the VP3 region to the 3′ untranslated region (UTR) of sewage sample Y12/2004 were determined. The number of nucleotides in each region was the same as that of CKV. The similarity of the nucleotide (amino acid) identity of a complete VP1 region was 90.5 % (94.8 %) between Y12/2004 and CKV US-PC0082. The phylogenic analyses based on the nucleotide and the deduced amino acid sequences of VP1 and 3D showed that Y12/2004 was independent from AiV, but closely related to CKV. These results suggested that CKV is present in Aichi Prefecture, Japan.
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Relationship between the severity of acne vulgaris and antimicrobial resistance of bacteria isolated from acne lesions in a hospital in Japan
Propionibacterium acnes and Staphylococcus epidermidis are normal skin inhabitants that are frequently isolated from lesions caused by acne, and these micro-organisms are considered to contribute to the inflammation of acne. In the present study, we examined the antimicrobial susceptibilities and resistance mechanisms of P. acnes and S. epidermidis isolated from patients with acne vulgaris in a university hospital in Japan from 2009 to 2010. Additionally, we analysed the relationship between the antimicrobial resistance of P. acnes and the severity of acne vulgaris. Some P. acnes strains (18.8 %; 13/69) were resistant to clindamycin. All strains had a mutation in the 23S rRNA gene, except for one strain that expressed erm(X) encoding a 23S rRNA methylase. Tetracycline-resistant P. acnes strains were found to represent 4.3 % (3/69) of the strains, and this resistance was caused by a mutation in the 16S rRNA gene. Furthermore, three strains with reduced susceptibility to nadifloxacin (MIC = 16 µg ml−1) were detected. When analysing the correlation between the antimicrobial resistance of P. acnes and S. epidermidis, more than 80 % of the patients who carried clindamycin-resistant P. acnes also carried clindamycin-resistant S. epidermidis. However, no epidemic strain that exhibited antimicrobial resistance was detected in the P. acnes strains when analysed by PFGE. Therefore, our results suggest that the antimicrobial resistance of P. acnes is closely related to antimicrobial therapy. Additionally, those P. acnes strains tended to be frequently found in severe acne patients rather than in mild acne patients. Consequently, the data support a relationship between using antimicrobial agents and the emergence of antimicrobial resistance.
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Characterization of enterotoxigenic Escherichia coli strains isolated from Nicaraguan children in hospital, primary care and community settings
Enterotoxigenic Escherichia coli (ETEC) is one of the most common causes of diarrhoea among young children in developing countries. ETEC vaccines offer promise in reducing the burden of ETEC disease, but the development of these vaccines relies on the characterization of ETEC isolates from a variety of settings. To best reflect the full spectrum of ETEC disease in León, Nicaragua, the aim of this study was to characterize ETEC strains isolated from children with diarrhoea attending different settings (hospital, primary care clinics and in the community) and children from different age groups. We characterized ETEC isolates in terms of their colonization factors (CFs) and enterotoxins, and determined whether these factors varied with setting and age group. Diarrhoeal stool samples were obtained from children under the age of 60 months from: (1) the regional public hospital, (2) four public primary care clinics, and (3) a population-based cohort. In total, 58 ETEC-positive isolates were analysed by multiplex-PCR assays for the identification of CFs (CS1, CS2, CS3, CS4, CS5, CS6, CS7, CS8, CS12, CS13, CS14, CS15, CS17, CS18, CS19, CS20, CS21, CS22 and CFA/I), and enterotoxins [heat-labile toxin (LT) and heat-stable variants STh and STp]. The frequency of CFs and enterotoxins was compared among the three settings and for different age groups, using Fisher’s exact test or a χ2 test. At least one CF was detected among one-half of samples; CS19 was detected among all strains in which a CF was identified, either alone or in combination with another CF. Among all CFs detected, 91.7 % were identified as members of the class 5 fimbrial family. CFs were detected more commonly among samples from infants captured in the health facility setting compared with the community setting. Overall, LT was detected among 67.2 % of samples, STh was detected among 20.7 % and both enterotoxins were detected among 12.1 %. The enterotoxin STh was detected more commonly among cases in the community, whilst a combination of STh and LT was detected more commonly among cases treated in health facilities. Our results suggest that, to protect against diarrhoeal cases associated with this E. coli pathotype in León, Nicaragua, an ETEC vaccine that effectively targets the archeotype CFA/I of the class 5 fimbrial family would be the most effective in this setting.
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Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci
We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02–0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.
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- Clinical microbiology and virology
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Hepatitis B and hepatitis C virus infections among antiretroviral-naive and -experienced HIV co-infected adults
More LessMost HIV positive people have not been tested for viral hepatitis and their treatments have not been optimized for possible co-infections. The aim of this study was to investigate the serological pattern of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among antiretroviral (ARV)-naive and -experienced HIV co-infected adults in Addis Ababa, Ethiopia. A total of 500 frozen HIV positive serum and plasma samples collected from ARV-naive (n = 250) and -experienced (n = 250) adults were randomly selected and screened for HBsAg, anti-HBs, HBeAg and anti-HCV using rapid two-site sandwich immunochromatographic assay. The test was performed at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. Positive specimens for HBsAg and anti-HCV markers were further confirmed using third generation ELISA. Of the 500 specimens tested, 15 (3 %), 58 (11.6 %), 3 (0.6 %), 18 (3.6 %), 3 (0.6 %) and 1 (0.2 %) were positive for HBsAg, anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. No specimen tested positive for both HBeAg and anti-HBs, and 442 (88.4 %) individuals were non-immune to HBV. Of the 250 ARV-naive individuals, 8 (3.2 %), 33 (13.2 %), 2 (0.8 %), 10 (4 %), 2 (0.8 %), and 1 (0.4 %) were positive for HBsAg, anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. Of the 250 ARV-experienced individuals, 7 (2.8 %), 25 (10 %), 1 (0.4 %), 8 (3.2 %), 1 (0.4 %), and 0 (0 %) were positive for HBsAg, Anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. In summary, seroprevalence of HIV/HBV and HIV/HCV co-infections was lower in Addis Ababa, Ethiopia, than in Sub-Saharan Africa and globally. HBV and HCV infections were not significantly different between HIV positive subjects who were or who were not on ARV. This suggests that the two groups have equal chance of being infected with these two viruses; despite this, disease progression could be different.
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Sequential, concomitant and hybrid first-line therapies for Helicobacter pylori eradication: a prospective randomized study
Helicobacter pylori eradication remains a challenge for physicians. Sequential, concomitant and the hybrid regimens have been proposed as novel, more effective therapies. We compare the efficacy of these therapies. Dyspeptic patients referred for upper endoscopy with H. pylori infection were enrolled. Patients were randomized to receive: (a) sequential therapy – 20 mg omeprazole and 1 g amoxicillin for 5 days, followed by 20 mg omeprazole, 500 mg clarithromycin and 500 mg tinidazole for the successive 5 days; (b) concomitant therapy – 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for either 5 days (5 day concomitant) or 14 days (14 day concomitant); or (c) hybrid therapy – 20 mg omeprazole and 1 g amoxicillin for 7 days, followed by 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for the successive 7 days. All drugs were given twice daily. Bacterial eradication was checked by using a [13C]urea breath test. In ‘intention-to-treat’ analysis, sequential therapy achieved the highest eradication rate, which was higher than that of 5 day concomitant therapy (90 vs 78.1 %; P = 0.02). The success rate did not statistically differ among the sequential and either 14 day concomitant (90 vs 86.3 %; P = not significant) or hybrid therapies (90 vs 82.7 %; P = not significant). The 10 day sequential, 14 day concomitant and 14 day hybrid therapies, but not the 5 day concomitant regimen, achieved similarly high eradication rates. The lower therapeutic cost coupled with the lower number of tablets needed would favour the sequential therapy as the first-line H. pylori treatment in clinical practice.
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- Oral microbiology
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Oral Candida carriage and immune status in Thai human immunodeficiency virus-infected individuals
Oral candidiasis is a common opportunistic infection among human immunodeficiency virus (HIV)-infected individuals, with growing concerns about the emergence of non-albicans species with resistance to antifungal agents. This cross-sectional study determined the prevalence of oral Candida species in Thai HIV-infected adults and factors affecting their colonization. Candida species were identified from oral rinse samples of 60 HIV-infected participants of the MTCT-Plus initiative and 49 healthy controls by culture-based and molecular assays. The prevalence of oral Candida carriage was similar in HIV-infected patients (56.6 %) and in controls (55.1 %, P = 0.87). Candida albicans was the most predominant species in both groups (94.1 % of Candida carriers in HIV, 88.9 % in control). Interestingly, Candida dubliniensis was the second most common species in controls (29.6 %) and the third in HIV-infected patients (11.8 %, P = 0.08). Multivariate analysis showed that, amongst HIV-infected individuals, CD4 count <200 cells mm–3 was associated with increased prevalence of oral carriage of both C. albicans (P = 0.03) and non-albicans species (P = 0.03). Moreover, patients with tuberculosis infection had a higher prevalence of the non-albicans species than those without (P = 0.03). Intriguingly, contraceptive use was also associated positively with non-albicans and multi-species carriage (P = 0.04 for both). However, use of antiretroviral drugs protected the patients from Candida carriage (P = 0.03), especially from C. albicans (P = 0.02). In conclusion, while HIV-infected individuals had a similar prevalence of oral Candida carriage to that of the control group, host immune status, tuberculosis infection, and contraceptive use may influence oral colonization of Candida, especially of the non-albicans species.
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- Correspondence
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Volumes and issues
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Volume 73 (2024)
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Volume 72 (2023 - 2024)
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Volume 71 (2022)
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Volume 70 (2021)
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Volume 69 (2020)
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Volume 68 (2019)
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Volume 67 (2018)
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Volume 66 (2017)
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Volume 65 (2016)
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Volume 64 (2015)
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Volume 63 (2014)
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