Studies on Campylobacter fetus subspecies jejuni

The work described in this thesis was principally directed at trying to develop a mouse model for human campylobacteriosis and also at defining the antigenic relationships between the human strains. Human diarrhoeal and normal stool specimens were examined for Campylobacter fetus ss, jejuni by culture on plates of Campylobacter selective medium, incubated at 4

Identification of Mycobacterium species following growth detection with the BACTEC MGIT 960 system by DNA line probe assay

AbstractBackgroundThe tuberculosis and infections caused by nontuberculous mycobacterial (NTM) species are increasing in patients presented with respiratory illness, and it is crucial to document the epidemiology of these infections.ObjectivesTo study the mycobacterial species and in vitro drug susceptibility trends of Mycobacterium tuberculosis found in the respiratory specimens.Materials and methodsA prospective descriptive study from July 2009 to December 2012. The BACTEC MGIT system tubes with growth were used in the study. GenoType Mycobacterium (Hain Diagnostika, Nehren, Germany) assays were used to identify the mycobacteria. The drug susceptibility testing was performed by the MGIT 960 system.ResultsA total of 1745 MGIT 960 system positive tubes were included. M. tuberculosis complex (MTC) constituted 67.45% of the yield isolated, 30.83% were nontuberculous mycobacterial species, 0.17% were Mycobacterium bovis BCG and 1.55% were not interpretable to species levels. Mycobacterium fortuitum (45.71%), Mycobacterium abscessus (26.21%) and Mycobacterium intracellulare (10.41%) were major NTM identified. The drug susceptibility study showed that 6.88% (81/1177) of MTC were drug-resistant TB, 56 isolates were resistant to one of the first-line anti-TB drugs, 25 isolates were found to be resistant to 2 or more first-line anti-TB drugs, of which 19 (20.46%) were MDR-TB and one of the isolates in the year 2011 was confirmed XDR-TB.ConclusionM. tuberculosis, M. fortuitum, M. abscessus and M. intracellulare were major mycobacterial species detected in the respiratory samples. The drug susceptibility testing showed that the majority of MTC were sensitive to first-line anti-TB drugs

In vitro activity of fluconazole and voriconazole against clinical isolates of Candida spp. by E-test method.

The in vitro susceptibility of clinical Candida isolates towards fluconazole and voriconazole was determined using the E-test method. A total of 41 clinical isolates recovered from patients since 2004 until 2009 from two local hospitals in Kuala Lumpur, Malaysia were used. These comprised Candida tropicalis, Candida albicans, Candida krusei, Candida parapsilosis, Candida rugosa, Candida dubliniensis and Candida glabrata. Strains from American Type Culture Collection were used as quality control. Lawn cultures of the isolates on RPMI-1640 agar medium supplemented with 2% glucose were incubated with the E-test strips at 35°C for 48 h. Our results show that 71% were susceptible to fluconazole and 90% were susceptible to voriconazole. All strains of C. krusei were resistant to fluconazole and 50% were susceptible in a dose-dependent manner to voriconazole. There were 66% and 33% of C. glabrata that were resistant to fluconazole and voriconazole. Our study revealed that majority of the clinical Candida isolates was susceptible to fluconazole and voriconazole with a small percentage being resistant to both the drugs

Detection of medically important Candida species by absolute quantitation real-time polymerase chain reaction

Background: Chronic obstructive pulmonary disease (COPD) is one of the most important causes of disability and mortality in the world. Although cigarette smoking and environmental pollutants have been recognized as the major causes of COPD, the role of infection in the pathogenesis and progression of COPD has also been reported. Objectives: The aim of the present study was to find the relationship between Helicobacter Pylori infection and COPD through anti H. pylori IgG serology, real time PCR of bronchoalveolar lavage and trans bronchial biopsy urease tests. Patients and Methods: This descriptive cross-sectional study was carried out on 60 adults with COPD. After obtaining the patient’s history, physical examination, spirometry and confirmation of COPD diagnosis by pulmonologist, subjects were selected through convenience sampling. In order to determine the severity and prognosis of disease, the global initiative for chronic obstructive lung disease (GOLD) criteria and BODE index were used. Subjects underwent bronchoscopy for obtaining bronchoalveolar lavage (BAL) samples and biopsy was performed. Biopsy and BAL samples were investigated respectively by urease test and real time PCR. Moreover, patients’ serum samples were serologically studied for detection of anti H. pylori IgG. Results: Mean age of the participants was 60.65 ± 9.15 years, and 25% were female and 75% were male. The prevalence rate of H. pylori in COPD patients was 10% according to real time PCR, 88.3% according to the serology test and 0% based on the urease test. According to the results of PCR and considering the severity of disease based on the GOLD criteria, from those with a positive PCR, one patient (16.6%) had very severe obstruction, three (50%) had severe obstruction and two patients (33.3%) had moderate obstruction. The relationship between H. pylori presence (based on PCR) and disease severity and prognosis was not statistically significant. Conclusions: These findings can justify the hypothesis of direct injury and chronic inflammation via inhalation and aspiration resulting in H. pylori colonization. In fact, it is thought that H. Pylori infection, beside the host genetic vulnerability and other environmental risk factors might make the patient susceptible to COPD or lead to COPD worsening. Although we found H. pylori infection in some patients with COPD, the results of this study, could not explain the pathogenic mechanisms of COPD

Cladosporium cladosporioides keratomycosis : a case report.

Keratomycosis is a frequent cause of ocular morbidity and blindness. Filamentous fungi such as Fusarium and Aspergillus have been reported to be leading causes of keratomycosis in India1 and China.2 Keratomycosis caused by Cladosporium cladosporioides, a pigmented fi lamentous fungus, is very rare. We report a case of Cladosporium cladosporioides keratomycosis identifi ed by polymerase chain reaction (PCR) and DNA typing

Candida albicans isolates from a Malaysian hospital exhibit more potent phospholipase and haemolysin activities than non-albicans Candida isolates

This study was aimed at determining the phospholipase and haemolysin activity of Candida isolates in Malaysia. A total of 37 Candida clinical isolates representing seven species, Candida albicans (12), Candida tropicalis (8), Candida glabrata (4), Candida parapsilosis (1), Candida krusei (4), Candida orthopsilosis (1) and Candida rugosa (7) were tested. In vitro phospholipase activity was determined by using egg yolk plate assay whereas in vitro haemolysin activity was tested by using blood plate assay on sheep blood Sabouraud's dextrose agar (SDA) enriched with glucose. Phospholipase activity was detected in 75% (9 out of 12) of the C. albicans isolates. Among the 25 non- C. albicans Candida isolates, phospholipase activity was detected in only 24% of these isolates. The phospholipase activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.002). Haemolysin activity was detected in 100% of the C. albicans, C. tropicalis, C. glabrata, C. krusei, C. parapsilosis, and C. orthopsilosis isolates while 75% of the C. krusei isolates and 12.3% of the C. rugosa isolates showed haemolysin activity. The haemolytic activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.0001).The findings in this study indicate that C. albicans isolates in Malaysia may possess greater virulence potential than the non-albicans species

Simplex and triplex polymerase chain reaction (PCR) for identification of three medically important Candida species

Candida species are a major cause of invasive infections in both critically ill and immunocompromised patients. Hence, rapid identification of these pathogens may facilitate specific therapy and patient management. The development of rapid and specific diagnostic methods remains a challenge. Herein, we developed the simplex and triplex polymerase chain reaction (PCR) for the identification of three medically important Candida species namely C. albicans, C. parapsilosis and C. tropicalis. The developed methods target the phospholipase B gene (PLB). The primers designed achieved highly specific identification of the selected species using both the simplex PCR and the triplex PCR formats, which were confirmed by DNA sequencing. The primers did not show any non-specific amplification when tested with DNA from other Candida species and other fungal species such as Aspergillus and Cryptococcus. These results showed that the PLB gene provides a novel target that could be used for the detection of medically important Candida species from clinical specimens.Key words: Candida species, primers, phospholipase B gene (PLB), polymerase chain reaction (PCR)

Identification of local clinical Candida isolates using CHROMagar Candida TM as a primary identification method for various Candida species.

The objective of our study was to study the effectiveness of CHROMagar Candida TM as the primary identification method for various clinical Candida isolates, other than the three suggested species by the manufacturer. We studied 34 clinical isolates which were isolated from patients in a local teaching hospital and 7 ATCC strains. These strains were first cultured in Sabouraud dextrose broth (SDB) for 36 hours at 35°C, then on CHROMagar plates at 30°C, 35°C and 37°C. The sensitivity of this agar to identify Candida albicans, Candida dubliniensis, Candida tropicalis, Candida glabrata, Candida rugosa, Candida krusei and Candida parapsilosis ranged between 25 and 100% at 30°C, 14% and 100% at 35°C, 56% and 100% at 37°C. The specificity of this agar was 100% at 30°C, between 97% and 100% at 35°C, 92% and 100% at 37°C. The efficiency of this agar ranged between 88 and 100% at 30°C, 83% and 100% at 35°C, 88% and 100% at 37°C. Each species also gave rise to a variety of colony colours ranging from pink to green to blue of different colony characteristics. Therefore, the chromogenic agar was found to be useful in our study for identifying clinical Candida isolates

Complex patterns of the HIV-1 epidemic in Kuala Lumpur, Malaysia: Evidence for expansion of circulating recombinant form CRF33_01B and detection of multiple other recombinants

AbstractThe HIV protease-reverse transcriptase (PR-RT) (1047 bp), gp120-env (891 bp) and gp41-env (547 bp) regions from the plasma of 115 HIV-1-infected patients in Kuala Lumpur (KL), Malaysia were sequenced. Detailed phylogenetic and bootscanning analyses were performed to determine the mosaic structure of the HIV-1 strains and their recombination breakpoint(s). Among the 50 patient samples in which all three regions could be amplified, the HIV-1 CRF01_AE subtype (46%) was predominant followed by subtypes B (10%) and B′ (6%). A total of 9/50 (18%) patients were infected with a CRF01_AE/B inter-subtype recombinant, displaying a recombinant form (RF)PR-RT, CRF01_AEgp120-env and CRF01_AEgp41-env. This RF was derived from the Thai variants of CRF01_AE and B′ subtype, with two distinct B′ subtype segments in the backbone of CRF01_AE, similar to the newly identified CRF33_01B. In addition, one sample demonstrated a close structural relationship with the new CRF33_01B in the PR-RT region but displayed B′ segment in part of the env region (RFPR-RT, CRF01_AE/B′gp120-env and B′gp41-env) indicating continuing evolution of CRF33_01B. The remaining 18% of samples were identified as unique recombinant forms (URFs)