Helicobacter pylori cagA gene variants in Malaysians of different ethnicity

We have defined DNA repeat variability in the 3′-terminus of the cagA gene of Helicobacter pylori strains from Malaysian patients of different ethnicities. We identified different alleles based on the EPIYA repeats. cagA types A-B-D and A-B-B-D are more similar to the sequence of Japanese strains, whereas cagA types A-B-C, A-B-C-C, A-B and A-C displayed similarity to strain 26695 sequences. A significant association was found between cagA genotypes and patients’ ethnicity, with cagA type A-B-D being predominantly isolated from Chinese patients and cagA type A-B-C from Malays and Indians. Our data further corroborate the possibility that variant biological activity of CagA may affect the host specificity and/or pathogenicity of H. pylori

Human Pathogen Shown to Cause Disease in the Threatened Eklhorn Coral Acropora palmata

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival

Interaction of imipenem and tigecycline against carbapenem-resistant acinetobacter baumanii: the relativity of synergism

Acinetobacter baumanii is an opportunistic bacterium that causes widespread nosocomial infections and tends to be multi-resistant to most of antibiotics. Tigecycline is a well-known antibiotic that possesses a wide-range of activities and is very active in vitro towards a variety of resistant pathogens, including A. baumanii. The aim of this study was to evaluate the effects of the imipenem and tigecycline combination against carbapenem-resistant A. baumanii (CRAB). The minimal inhibitory concentration (MIC) was determined using the E-test method. The microbroth checkerboard technique was employed to determine the effects of the imipenem and tigecycline interaction by obtaining the fractional inhibitory concentration (FIC) index value. A time kill (TK) study was performed to identify any synergistic effects when both imipenem and tigecycline were used against CRAB strains. The result demonstrated that all A. baumanni strains exhibited imipenem MIC values of 32 μg/mL. The combination of imipenem and tigecycline demonstrated an additive effect (FIC > 0.5-4) against all of the strains and synergistic activity (decrement of > 2 log10 CFU/mL) towards AC 34/07 and AC 32/06 strains. The use of imipenem in combination with tigecycline resulted in a more efficient activity and an increased capability to control CRAB infections. This effect showed potential combination and may be of importance in the development or modification of antimicrobial agents for the treatment of CRAB infections

Four years analysis of helicobacter pylori infection among patients with dyspeptic at Universiti Kebangsaan Malaysia Medical Centre

Helicobacter pylori has been implicated as an aetiologic agent for type B chronic gastritis, peptic ulcer and gastric cancer. It is considered the most common bacterial infection in the world with approximately 50% of the population being infected. The majority of infected individuals are asymptomatic, with some developing gastritis only. However, chronic infection with H. pylori without antibiotic treatment predisposes infected individuals to the development of gastric cancer. The aim of this study is to determine active H. pylori infection among patients with symptoms of dyspepsia using three combinations of diagnostic methods. In this report, we studied 1,376 consecutive patients who underwent upper gastrointestinal endoscopy at Universiti Kebangsaan Malaysia Medical Center (UKMMC) for dyspepsia from the period January 1999 to December 2002. The classification of patient’s diagnosis was assessed by endoscopic and histological examination. The H. pylori status was determined by rapid urease test, histological examination or H. pylori culture. Presence of H. pylori infection was confirmed in 30.8% of patients with dyspepsia. H. pylori infection was more prevalent in older patients and in males compared to females. Patients with severe gastroduodenal diseases were more commonly infected with H. pylori. There was a significant difference in H. pylori prevalence among the different ethnic groups. Indians had the highest infection rate (45.4%), followed by Chinese (36.8%) and the lowest were seen in Malays (18.3%). This finding on determination of active H. pylori infection among patients with dyspepsia is consistent with serological studies that showed racial differences in H. pylori prevalence. However, the pattern of H. pylori infection does not reflect the prevalence of severe gastroduodenal diseases among different ethnic groups

Clostridium difficile infection: clinico-epidemiological perspective.

Clostridium difficile infection (CDI) causes mild to severe diarrhoea and pseudomembranous colitis in patients who had prior antibiotic exposure. Despite CDI being prevalent worldwide, its epidemiological data is scanty in Malaysia. This study aimed to determine the prevalence and incidence of CDI at Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Stool specimens from 147-suspected CDI patients were obtained from 1 November 2011 until 31 October 2012. The presence of C. difficile toxin A and/or B were detected using a commercial immunochromatographic kit (Wampole™ Tox A/B Quik Chek). Surveillance data was collected from patients’ medical records to establish the demographic and clinical characteristics. The overall prevalence and incidence of CDI in UKMMC was 6.1% and 5.2 cases per 10 000 patient-days, respectively. Among nine CDI patients, 77.8% were males and 55.6% were Chinese. CDI was most common in medical wards (88.9%). The median age was 60 years and the median length of hospital stay was 13 days. Majority (88.9%) of CDI patients received antibiotics eight weeks prior to CDI. Penicillin-beta-lactamase inhibitors were the most common antecedent antibiotics. Five (55.6%) CDI patients received acid suppressant medications. The in-hospital mortality rate was 22.2%. In conclusion, the prevalence and incidence of CDI at UKMMC is relatively low and occurs sporadically

Phylogenetic analysis of respiratory syncytial virus identified at Universiti Kebangsaan Malaysia Medical Centre

Human respiratory syncytial virus (RSV) is an important cause of acute respiratory tract infection in infants and young children. Phylogenetic analysis for RSV in Malaysia has not been reported before. We investigated the genetic features of RSV in respiratory specimens from March to August 2011 with molecular methods. From a total of 130 throat swab and nasopharyngeal aspirate specimens, 54 (41.5%) were positive with RSV, identified by in-house real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay. Thirty-four out of 54 (63.0%) RSV positive patients were children below two years old and two (1.4%) were adults. Phylogenetic analysis showed 39 isolates were genotype GA5, 13 genotypes GA2, one genotype GA1 and one genotype GA7. The findings indicated four genotypes of RSV circulating in the country and the predominant genotype is GA5