ABSTRACT
Background: Dengue virus serotyping is crucial from clinical management and epidemiological point of view. Aims: To compare efficacy of two molecular detection and typing methods, namely, multiplex reverse transcription polymerase chain reaction (RT‑PCR) and real‑time Hybprobe assay using a panel of known dilution of four reference Dengue virus strains and a panel of sera collected from clinically suspected dengue patients. Settings: This study was conducted at a tertiary‑care teaching hospital in Delhi, India. Materials and Methods: Dengue serotype specific virus strains were used as prototypes for serotyping assays. Viral load was quantified by quantitative real time reverse transcription polymerase chain reaction (qRT‑PCR). Acute phase serum samples were collected from 79 patients with clinically suspected Dengue fever on their first day of presentation during September‑October 2012. Viral RNA from serum and cell culture supernatant was extracted. Reverse transcription was carried out. Quantitative detection of DENV RNA from reference strain culture supernatants and each of the 79 patient samples by real‑time PCR was performed using light cycler Taqman master mix kit. Serotyping was done by multiplex RT‑PCR assay and Hybprobe assay. Results: The multiplex RT‑PCR assay, though found to be 100% specific, couldn’t serotype either patient or reference strains with viral load less than 1000 RNA copies/ml. The Hybprobe assay was found to have 100% specificity and had a lower limit of serotype detection of merely 3.54 RNA copies/ml. Conclusions: HybProbe assay has an important role especially in situations where serotyping is to be performed in clinical samples with low viral load.
ABSTRACT
Helicobacter pylori (HP) is causally associated with peptic ulcer disease and gastric carcinoma. Determination of the prevalence of HP infection in dyspepsia patients’ in particular geographical area is imperative for the appropriate management of dyspepsia. HP antigen detection in stool is a noninvasive diagnostic test of HP infection. This prospective study was conducted to find out the prevalence of HP infection based on stool antigen testing in dyspeptic patients who had also undergone upper gastrointestinal (GI) endoscopy. This study highlights the high prevalence of HP infection in dyspeptic Indian patients, particularly males, and emphasizes the growing importance of the bacterium causing infection among children. We also found HP stool antigen testing to be superior to upper GI endoscopy for detecting HP infection. Hence, we recommend initial testing for HP stool antigen in dyspeptic patients before initiating treatment and before carrying out any invasive procedure such as endoscopy.
ABSTRACT
Enteric fever caused by Salmonella enterica is a systemic infection with high rates of morbidity and mortality. Increasing antibiotic resistance in S. enterica has led to shift in the choice of antibiotics used against this organism from chloramphenicol and ampicillin to trimethoprim-sulfamethoxazole, fl uoroquinolones, and extendedspectrum cephalosporins. Resistance to cephalosporins, due to the production of extended-spectrum beta-lactamases (ESBLs), is the cause of serious concern worldwide. So far, these enzymes have been detected in many species of the family Enterobacteriaceae including different serotypes of S. enterica. To the best of our knowledge, however, ESBL production in Salmonella Paratyphi A has not yet been reported from India. We present here a case of ESBL producing Salmonella Paratyphi A from India. This is a worrisome fi nding with grave clinical implications, since the dissemination of this resistance trait would further limit the therapeutic options available for the treatment of enteric fever.
ABSTRACT
A new subspecies of Staphylococcus hominis described by Kloos et al. in 1998 and named S. hominis subsp. novobiosepticus (SHN) has been implicated in nosocomial outbreaks. Multidrug resistance, including resistance to novobiocin and oxacillin, is a particularly important feature of SHN. In our institute, we encountered 13 cases of S. hominis subsp. hominis in cancer patients with septicemia, of which seven were methicillin resistant. The isolates were identifi ed by VITEK® 2 compact automated system, using GP REF 21342 identifi cation card and antimicrobial susceptibility testing card P-628. The biochemical reactions and antibiotic susceptibility pattern of the seven methicillin-resistant isolates were re-analyzed and patient details were re-checked to fi nally identify them as SHN. The increasing number of cases reporting isolation of SHN from biological specimens point to potential virulence and clinical importance of this bacterium.