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  Citation statistics : Table of Contents
   2011| October-December  | Volume 29 | Issue 4  
    Online since November 24, 2011

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Association of platelet count and serological markers of dengue infection- importance of NS1 antigen
RD Kulkarni, SS Patil, GS Ajantha, AK Upadhya, AS Kalabhavi, RM Shubhada, PC Shetty, PA Jain
October-December 2011, 29(4):359-362
DOI:10.4103/0255-0857.90159  PMID:22120794
Introduction: Dengue is an acute viral infection with potential fatal complications. Specific antibody detection has been the mainstay of diagnosis which is prone for both false positive and false negative reactions. The newer parameter NS1 appears to be highly specific and reliable for diagnosis of dengue infection from the first day of fever. Platelet count is the only accessory test for diagnosis of dengue infection in the peripheral laboratories. Therefore, we tried to evaluate the association of platelet counts against NS1 and IgM/IgG in dengue infections. Materials and Methods: Serum samples from clinically suspected dengue cases were tested for NS1, IgM and IgG by immunochromatography-based test. Platelet counts were obtained for all positive cases and 150 dengue seronegative cases of fever that served as controls. Test results of dengue-specific parameters were compared against platelet counts. The proportions obtained were compared by Standard error of the difference between the proportions (SEP test). Results: Of 2104 samples tested, 320 were positive for one or more dengue parameters. Of the 320, 95 were positive for NS1 only, 161 showed IgM only while 9 showed IgG only. More than one marker was detected in the remaining 55 samples. Thrombocytopenia was more consistently associated whenever NS1 was detected compared to antibody detection (P value <0.001). Conclusions: Inclusion of NS1 in the diagnosis of dengue increases the detection rate significantly. In cases of fever, thrombocytopenia is more consistently found in dengue positive rather than dengue negative subjects. It correlates well when NS1 and IgM are detected simultaneously.
  3 8,451 898
Laboratory aspects of clinically significant rapidly growing mycobacteria
R Set, J Shastri
October-December 2011, 29(4):343-352
DOI:10.4103/0255-0857.90157  PMID:22120792
The pathogenic potential of the rapidly growing mycobacteria (RGM) has started being recognized. This is due to more sensitive and specific techniques in the laboratory. The RGM are generally defined as nontuberculous species of mycobacteria that show visible growth on agar media within 7 days. RGM are widely distributed in nature and have been isolated from natural water, tap water, and soil. Several biochemical tests, high performance liquid chromatography, and molecular techniques have been developed for rapid identification of these species. The American Thoracic Society and the Infectious Disease Society of America recommend that RGM should be identified to the species level using a recognized acceptable methodology such as polymerase chain reaction restriction enzyme analysis or biochemical testing and routine susceptibility testing of RGM should include amikacin, imipenem, doxycycline, the fluorinated quinolones, a sulphonamide or trimethoprim-sulphamethoxazole, cefoxitin, clarithromycin, linezolid, and tobramycin. The diseases caused by these organisms have varied manifestations. They have been responsible for a number of healthcare-associated outbreaks and pseudo-outbreaks. For recognition of outbreaks, it is important to be familiar with the causative organisms like RGM which are most frequently involved in healthcare-associated outbreaks and pseudo outbreaks. It is essential to intervene as soon as possible to interrupt this transmission. Large gaps still exist in our knowledge of RGM. Unquestionably more studies are required. Through this review, we wish to emphasize that reporting of RGM from clinical settings along with their sensitivity patterns is an absolute need of the hour.
  3 5,476 521
Transfusion-transmitted hepatitis E: Is screening warranted?
M Bajpai, E Gupta
October-December 2011, 29(4):353-358
DOI:10.4103/0255-0857.90158  PMID:22120793
Hepatitis E virus (HEV) is an emerging infectious threat to blood safety. In recent years, there have been a number of publications delineating this threat by providing evidence of the transmissibility of this virus through transfusions. The extent of transmission and its clinical relevance are issues under debate at present. HEV usually causes a self-limiting illness which subsides in a few weeks barring a few cases where fulminant hepatic failure occurs. The virus poses a risk of higher morbidity and mortality in pregnant females, patients with pre-existing liver disease and solid organ transplant recipients. As these categories of patient often require repeated transfusions or massive transfusions, they are exposed to a greater risk of transmission of HEV. At present, there is little evidence to advocate universal screening for this virus but considering that there is no definitive treatment for HEV induced hepatitis, selective screening should be advocated in blood products for high risk recipients in endemic areas.
  3 4,993 381
Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea
R Nath, L Saikia, G Choudhury, PP Das
October-December 2011, 29(4):422-425
DOI:10.4103/0255-0857.90186  PMID:22120808
Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. It was infrequently recovered from clinical specimens probably because of inadequate processing of non-fermenting oxidase-positive gram-negative bacilli. We report here isolation of S. algae in pure culture and mixed with E. coli from two cases of acute gastroenteritis with bloody mucous containing diarrhea occurring at the same time. As this organism is not a normal flora of the gut, the possible source of infection may be fish contaminated with the organism. Whether this bacterium can be considered an enteric pathogen needs to be evaluated. The cases were clinically diagnosed as acute bacillary dysentery. The bacterium was identified by 16S r-RNA gene sequence analysis.
  2 5,273 164
Periorbital mass with cellulitis caused by dirofilaria
K Joseph, AR Vinayakumar, S Criton, MS Vishnu, SE Pariyaram
October-December 2011, 29(4):431-433
DOI:10.4103/0255-0857.90190  PMID:22120811
Dirofilariasis is a zoonotic disease caused by Dirofilaria, a parasite of domestic and wild animals. The disease is transmitted by inoculation of mosquitoes infected with the microfilariae during their blood meal. Accidental infection of man results in lung nodule, subcutaneous mass anywhere in the body or ocular lesion that may be subconjunctival or periorbital. The incidence of ocular dirofilariasis is on the rise in several parts of India particularly in Kerala. Here we report a case of ocular dirofilariasis with cellulitis presenting as a periorbital mass.
  2 3,842 151
Complement-dependent lymphocytotoxicity crossmatch in deceased donor renal transplant: A single institutional experience
R Deepa, P Balapriya, KG Venkatesh, T Sabeetha, J Sasikala, G Jayalakshmi
October-December 2011, 29(4):414-417
DOI:10.4103/0255-0857.90182  PMID:22120805
Complement-dependent lymphocytotoxicity crossmatches (n=217) between 47 deceased donors and 150 potential renal recipients were retrospectively studied. A negative cross match was reported in 48 (22.1%), doubtful positive in 126 (58.1%), weakly positive in 32 (14.7%) and positive in 11 (5.1%). No autoantibodies were detected. Renal transplantation was performed in 35.5% of the potential recipients. There was no incidence of hyperacute rejection. The graft survival rate was 88% at 15 months of follow up. The study concludes that a negative pretransplant lympocytotoxicity crossmatch using the basic National Institute of Health technique eliminates hyperacute rejection, but carries drawbacks, which require modification and supplementation with more sensitive and specific assays.
  1 4,909 157
Severe pigmented keratitis caused by Cladorrhinum bulbillosum
DU Gajjar, AK Pal, JM Santos, BK Ghodadra, AR Vasavada
October-December 2011, 29(4):434-437
DOI:10.4103/0255-0857.90191  PMID:22120812
We report a case of severe pigmented keratitis with poor prognosis, caused by Cladorrhinum bulbillosum. Antifungal treatment with topical natamycin and fluconazole eye drops and oral tablet fluconazole failed to heal the ulcer and resulted in perforation. The causative fungus, C. bulbillosum, was identified on the basis of its typical microscopic features and 98% sequence homology to ex-type isolate CBS 304.90 (accession no. FM955448). The results of an in vitro antifungal susceptibility test indicated that the isolate was susceptible to natamycin, amphotericin B, fluconazole and itraconazole. The present case is the third case of keratitis and the second case of human keratitis. Compromised immunity due to liver cirrhosis could lead to a failed prognosis even when the fungal isolate is highly susceptible to antifungal treatment.
  1 2,982 106
Successfully treated Mycobacterium abscessus mastitis: A rare cause of breast masses
KK Yasar, F Pehlivanoglu, G Sengoz, N Cabioglu
October-December 2011, 29(4):425-427
DOI:10.4103/0255-0857.90187  PMID:22120809
Rapidly growing mycobacteria are pathogens responsible for cutaneous or subcutaneous infections especially occurring after injection, trauma or surgery. We describe a patient with Mycobacterium abscessus mastitis that presented as a mass lesion and haemorrhagical discharge. It was initially diagnosed and treated as fibrocystic disease and non-specific abscess. Full recovery was obtained with combination therapy of clarithromycin, linezolid and amikacin without surgical debridement followed by several abscess aspirations. Atypical mycobacteria should be considered in diagnosis of chronic breast lesions in endemic areas. This is the first reported case of mastitis due to M. abscessus in Turkey.
  1 4,820 114
Microsporidial keratoconjunctivitis in an immunocompetent patient with a past history of laser in situ keratomilieusis surgery
ML Bommala, S Nalamada, S Sharma, P Garg
October-December 2011, 29(4):428-430
DOI:10.4103/0255-0857.90189  PMID:22120810
Ocular infection with microsporidia has been documented in both immunocompetent and immunocompromised patients. Sources and mode of human infection with microsporidia have been difficult to ascertain although exposure to water may be an important risk factor. Of four genera that have been reported in human disease, only the genera Nosema, Encephalitozoon and Septata are documented to cause ocular infection. Here, in our case a healthy 30-year-old man who had undergone bilateral laser in situ keratomilieusis surgery two and half years back presented with a 10-day history of redness and 4-day history of blurring of vision in the right eye. On presentation, his best-corrected visual acuity was 20/20 partial in both eyes. Slit lamp examination revealed multiple pin head shaped infiltrates in the right cornea. Examination of the left eye was unremarkable. Based on microscopic demonstration of numerous microsporidial spores in the corneal scrapings, a diagnosis of microsporidial keratitoconjunctivitis was made. On treatment with oral albendazole, the cornea became clear with complete resolution of symptoms and signs within two weeks.
  1 2,930 139
Brevundimonas vesicularis bacteremia: A rare case report in a female infant
SM Bhatawadekar, J Sharma
October-December 2011, 29(4):420-422
DOI:10.4103/0255-0857.90184  PMID:22120807
Brevundimonas vesicularis has rarely been isolated from clinical specimens. We report here a case of B. vesicularis bacteremia in a female infant who presented with fever, vomiting and altered sensorium. USG abdomen showed mild hepatomegaly, moderate ascitis with bilateral mild basal pleural effusion. Blood culture was processed by BACTEC BD. Isolate was identified as B. vesicularis, by API ID 32 GN automated system. We have come across only one report of neonatal sepsis caused by B. vesicularis from India. To the best of our knowledge, this is one of the rare case reports of B. vesicularis bacteremia in a female infant.
  1 11,741 174
Schizophyllum commune sinusitis in an immunocompetent host
B Swain, R Panigrahy, D Panigrahi
October-December 2011, 29(4):439-442
DOI:10.4103/0255-0857.90194  PMID:22120814
Schizophyllum commune is widely distributed in the nature, but it rarely causes human infection. We have isolated this mould in a 46-year-old immunocompetent, non-diabetic patient with chronic sinusitis, previously treated with multiple antibiotics and topical steroid nasal drops with no response. Materials obtained from the nasal sinus during the endoscopic surgery, on KOH mount and histopathological study revealed broad septed hyaline hyphae. Growth on the Sabouraud's dextrose agar and potato dextrose agar produced white moulds with microscopic and macroscopic characters of S. commune. Till date there are few reports of S. commune sinusitis in immunocompetent individuals Worldwide. This is the first reported case in India to the best of our knowledge.
  1 3,941 147
Need to establish importance of polymerase chain reaction for tuberculosis in smear as well as culture negative non-respiratory samples
V Gupta, N Singla, R Garg, N Gulati, H Rani, J Chander
October-December 2011, 29(4):445-446
DOI:10.4103/0255-0857.90199  PMID:22120818
  1 1,604 121
Detection of anthrax toxin genetic sequences by the solid phase oligo-probes
KC Addanki, M Sheraz, K Knight, K Williams, DG Pace, O Bagasra
October-December 2011, 29(4):372-378
DOI:10.4103/0255-0857.90169  PMID:22120797
Purpose: There is an urgent need to detect a rapid field-based test to detect anthrax. We have developed a rapid, highly sensitive DNA-based method to detect the anthrax toxin lethal factor gene located in pXO1, which is necessary for the pathogenicity of Bacillus anthracis. Materials and Methods: We have adopted the enzyme-linked immunosorbent assay (ELISA) so that instead of capturing antibodies we capture the DNA of the target sequence by a rapid oligo-based hybridization and then detect the captured DNA with another oligoprobe that binds to a different motif of the captured DNA sequences at a dissimilar location. We chose anthrax lethal factor endopeptidase sequences located in pXO1 and used complementary oligoprobe, conjugated with biotin, to detect the captured anthrax specific sequence by the streptavidin-peroxidase-based colorimetric assay. Result: Our system can detect picomoles (pMoles) of anthrax (approximately 33 spores of anthrax) and is >1000 times more sensitive than the current ELISA, which has a detection range of 0.1 to 1.0 ng/mL. False positive results can be minimized when various parameters and the colour development steps are optimized. Conclusion: Our results suggest that this assay can be adapted for the rapid detection of minuscule amounts of the anthrax spores that are aerosolized in the case of a bioterrorism attack. This detection system does not require polymerase chain reaction (PCR) step and can be more specific than the antibody method. This method can also detect genetically engineered anthrax. Since, the antibody method is so specific to the protein epitope that bioengineered versions of anthrax may not be detected.
  1 3,484 123
Evaluation of the effect of presence of blood in the stomach on endoscopic diagnostic tests for Helicobacter pylori infection
S Mittal, S Trakroo, V Kate, S Jagdish
October-December 2011, 29(4):379-382
DOI:10.4103/0255-0857.90170  PMID:22120798
Introduction: Presence of blood in the stomach has been thought to affect the performance of diagnostic tests used in detecting Helicobacter pylori (H. pylori) in the stomach. This study evaluated the effect of blood on the efficacy of rapid urease test (RUT) and microscopic appearance of the biopsy after staining with Giemsa stain. Materials and Methods: Patients with bleeding oesophageal varices who met the inclusion criteria were tested for H. pylori by RUT and microscopic examination of the biopsy. A repeat endoscopy, RUT and histology were done one month following initial presentation. The performance of the diagnostic tests was evaluated with and without the presence of intraluminal blood. A combined result of the two tests, RUT and histology, carried out in presence or absence of blood for the diagnosis of H. pylori, when considered together was considered as the gold standard. Results: Thirty six patients included in the study were in the ages ranging between 15-60 years (mean age = 44.14 years ±2.1). The combination of tests at both visits showed 20/36 (55.6%) patients were positive for H. pylori. The decrease in H. pylori positivity in the presence of blood was significant for RUT (8.3% vs. 38.9%; P=0.005) and combined test (19.4% vs. 47.2%; P=0.02) but the decrease in positivity for histology (11.1% vs 30.6%) was not significant (P=0.08). In the presence of blood, the sensitivity of RUT, histology and combined tests were 15%, 20% and 35%, respectively. In the absence of blood, the sensitivity of RUT, histology and combination of tests was 70%, 55% and 85%, respectively. Conclusion: Blood in the stomach significantly decreased the sensitivity of RUT, histology and the combination of both. Negative results of these tests in acute upper gastro intestinal (GI) bleeding should therefore be interpreted carefully.
  1 2,897 194
A study of tubercular lymphadenitis: A comparison of various laboratory diagnostic modalities with a special reference to tubercular polymerase chain reaction
SA Patwardhan, P Bhargava, VM Bhide, DS Kelkar
October-December 2011, 29(4):389-394
DOI:10.4103/0255-0857.90173  PMID:22120800
Objective: The purpose of our study was to compare various laboratory diagnostic methods, namely histopathological examination, Ziehl-Neelsen (ZN) stain, AFB culture by conventional Lowenstein-Jensen (LJ) method and fluorescence-based mycobacterial growth indicator tube (MGIT) technique and polymerase chain reaction (PCR) in clinically suspected cases of tubercular lymphadenitis. Materials and Methods: A total of 65 lymph nodes biopsied from patients clinically suspected of having tubercular lymph nodes were included. Specimens were processed for AFB culture after NaOH-NALC concentration and inoculation on LJ medium and using the MGIT system. PCR was performed on all specimens using a commercial nested PCR kit targeting IS6110 insertion element of Mycobacterium tuberculosis complex. All lymph node specimens were subjected to histopathological examination. Results: Of the 65 lymph nodes, 37 (56.9%) were positive on MGIT culture and 45 (69.2%) were positive by PCR. Histopathology showed maximum sensitivity (96%) but with compromised specificity (78.5%). PCR showed 90.1% sensitivity and 100% specificity. The mean turnaround time for mycobacterial growth in smear negative specimens was 30 days determined by LJ and 20 days by MGIT techniques. Conclusion: PCR is a rapid and useful method for diagnosis of TB lymphadenitis and definitely increases the positive predictive value of a positive histopathology report. MGIT is better than LJ culture as regards time to positivity and higher yield.
  1 4,999 342
Opportunistic infections in relation to antiretroviral status among AIDS patients from south India
S Srirangaraj, D Venkatesha
October-December 2011, 29(4):395-400
DOI:10.4103/0255-0857.90175  PMID:22120801
Background: There is a need to generate data from India on relative frequencies of specific opportunistic infections (OIs) in different regions and their relation to the choice of commonly used generic highly active anti-retroviral therapy (HAART) regimens. Objectives: To document the prevailing prevalence pattern of OIs both before and after HAART, to look for reduction in OIs following HAART, to assess the risk of developing new OIs within 6 months of HAART initiation and to see if there is any difference in the risk of developing a new OI within 6 months of HAART initiation, for those on Efavirenz (EFV)-based regimens and Nevirapine (NVP)-based regimens. Materials and Methods: In a prospective observational cohort study conducted in South India involving 108 ART-naive AIDS patients, different pathogens were isolated and identified using standard laboratory techniques. Data analysis was done using SPSS software (version 16.0). Risk of developing an OI after HAART initiation was assessed using the likelihood ratio test from Cox regression models. Results: Tuberculosis (53.4%), oral Candidiasis (27.2%) and Herpes Zoster (14.7%) were the common infections seen. There was a drastic reduction of 96.59% in OI events after 6 months of HAART. The risk of developing an OI within 6 months of HAART initiation was 5.56%. Time to development of an OI in the first 6 months of HAART was shorter for the NVP-based regimens than with EFV-based regimens, but this difference was not statistically significant (HR=0.891, 95% CI: 0.179-4.429; P=0.888). Conclusion: Tuberculosis is the most important OI before initiation of HAART. Both EFV and NVP-based regimens are equally efficacious in controlling OIs.
  1 3,701 394
Seroepidemiological study of human metapneumovirus in New Delhi, India
S Banerjee, WM Sullender, RK Ahuja, S Broor
October-December 2011, 29(4):363-367
DOI:10.4103/0255-0857.90162  PMID:22120795
Purpose: There are a few seroepidemiological studies reported on human metapneumovirus (hMPV) as hMPV was only discovered in the year 2001. This respiratory virus has been reported to be ubiquitous and associated with respiratory tract infections in all age groups. The present study aimed at determining the prevalence of antibodies to hMPV in children and adults of 1 month to 55 years of age. Materials and Methods: Serum samples from 100 study subjects were tested for hMPV antibody by an in-house ELISA system that used hMPV-infected cell lysate antigen. Result: The prevalence of antibody to hMPV was lowest in children less than 5 years of age (60%) and increased throughout age to > 80%. Similarly, geometric mean titres were 1:180 in children less than 5 years of age and reached a peak of 1:419 in adults over 35 years of age. Conclusion: The results show that hMPV infection is acquired early in life and re-infection in later life may maintain the seroprevalence and antibody levels in adult population.
  1 2,500 191
The role of a commercial enzyme immuno assay antigen detection system for diagnosis of C. trachomatis in genital swab samples
A Mukherjee, S Sood, M Bala, G Satpathy, N Mahajan, A Kapil, VK Sharma
October-December 2011, 29(4):411-413
DOI:10.4103/0255-0857.90180  PMID:22120804
In the present pilot study, endocervical and urethral swabs collected from 100 patients attending sexually transmitted disease (STD) clinics and regional centre for STD in two referral hospitals in New Delhi were analyzed by enzyme immune assay (EIA), polymerase chain reaction (PCR) and direct fluorescent antibody (DFA) for detection of C. trachomatis. It was found that EIA could detect a very low number of cases (3/100) as against DFA (11/100) and PCR (9/100). Thus, in spite of the widespread availability, lower cost and ease of performance of the enzyme-linked-immunosorbent serologic assay, the present study highlights the need to employ sophisticated diagnostic tools like DFA and PCR for detection of Chlamydia trachomatis in STD patients.
  - 2,828 177
Concurrent mycetoma and chromomycosis
R Murthy, JP Swain
October-December 2011, 29(4):437-439
DOI:10.4103/0255-0857.90192  PMID:22120813
Chromoblastomycosis and Madura foot are chronic localised mycotic infection of the skin and subcutaneous tissue that follows the implantation of the fungi through minor trauma, mainly found in persons working outdoors on bare foot. In cases where both Madura and chromoblastomycosis are present, the treatment becomes difficult with low cure rates and frequent relapses. Here, we present such a very rare case of a 38-year-old cattle farmer who presented with verrucose nodules, tumefaction and multiple discharging nodules on the left lower 1/3 rd leg and foot since last 9 years. Direct KOH mount of the verrucose tissue showed Fonsecaea pedrosoi sclerotic muriform bodies and a biopsy of one granule discharging nodule demonstrated fungal mycetoma. He was put on tab. Itraconazole 200 mg o.d. and cotrimoxazole bid for 6 months with very little improvement. The rarity of this combination is most probably due to different geographical distribution.
  - 3,567 132
A Q fever case mimicking crimean-congo haemorrhagic fever
O Karabay, HT Gozdas, G Ozturk, N Tuna, AC Utku
October-December 2011, 29(4):418-419
DOI:10.4103/0255-0857.90183  PMID:22120806
Coxiella burnetii is the bacterium that causes Q fever. Human infection is mainly transmitted from cattle, goats and sheep. The disease is usually self-limited. Pneumonia and hepatitis are the most common clinical manifestations. In this study, we present a case of Q fever from the western part of Turkey mimicking Crimean-Congo haemorrhagic fever (CCHF) in terms of clinical and laboratory findings.
  - 2,663 103
Primary pulmonary infection caused by 20% acid fast Nocardia brasiliensis
V Rawat, Umesh , N Thapliyal, DC Punera
October-December 2011, 29(4):446-447
DOI:10.4103/0255-0857.90200  PMID:22120819
  - 2,182 125
Use of the microsoft excel for automated plotting of Levey Jennings charts
D Sharma
October-December 2011, 29(4):448-449
DOI:10.4103/0255-0857.90201  PMID:22120820
  - 29,221 325
Comment on: Yeast identification in routine clinical microbiology laboratory and its clinical relevance
Juhi Taneja, Jagdish Chander
October-December 2011, 29(4):443-443
DOI:10.4103/0255-0857.90196  PMID:22120815
  - 1,833 258
Omission of extended spectrum β lactamases detection: Are the new Clinical Laboratory Standards Institute guidelines misleading?
C Chande, S Makhija, S Lilani, R Shirpurkar, P Veer, A Chivate, P Patekar, A Joshi
October-December 2011, 29(4):443-444
DOI:10.4103/0255-0857.90197  PMID:22120816
  - 1,610 179
Spectrum of Leptospira species identified in patients with leptospiral uveitis in an ophthalmological institute in South India
V Batmanabane, GP Chidambaranathan, S Rathinam
October-December 2011, 29(4):444-445
DOI:10.4103/0255-0857.90198  PMID:22120817
  - 1,582 103
Molecular diagnostic tests: Keeping up with mutations
R Kanungo, D Metzgar
October-December 2011, 29(4):325-326
DOI:10.4103/0255-0857.90152  PMID:22120788
  - 2,389 432

October-December 2011, 29(4):449-449
  - 1,580 56
R Kanungo
October-December 2011, 29(4):452-452
  - 1,616 108
A rapid, sensitive and reliable diagnostic test for scrub typhus in China
Zhang Lijuan, He Si, Jin Yuming, Li Liang, Li xuemei, Liu Lianying, Yu Huilan, Yu Qiang, Chen Chuangfu, Wang Shiwen
October-December 2011, 29(4):368-371
DOI:10.4103/0255-0857.90166  PMID:22120796
Purpose: To evaluate the performances for detection of IgM and IgG antibodies to Orientia. tsutsugamushi (Ot) using a gold conjugate-based rapid diagnostic test (RDT). Materials and Methods: The RDT employing mixture recombinant 56-kDa proteins of O. tsutsugamushi and the mIFA assay was performed on 33 patients from Fujian and Yunnan province respectively and 94 positive sera (36 from Hainan province and 58 from Jiangsu province) from convalescent stages of the patients with scrub typhus respectively and 82 negative sera from healthy farmers from Anhui province and Beijing City respectively in 2009. A comparison of the RDT and mIFA assay was performed by using the c2 test and the P level of ≤0.05 was considered to be significant. Results: Among these 94 positive sera from convalescent stages of the illness and 82 sera from control farmers, the specificity of RDT was 100% for both IgM and IgG tests. In 33 cases with scrub typhus, 5 cases were positively detected earlier by RDT than by mIFA for the IgM test, and 2 cases were positive for the IgG test. The sensitivities of RDT were 93.9% and 90.9% for IgM and IgG, respectively. Considering IgM and IgG together, the sensitivity was 100%. The geometric mean titre (GMT) of IFA and the RDT assay in diluted sera from confirmed cases were 1:37 versus 1:113 respectively (P<0.001) for IgM test and 1:99 versus 1:279 respectively (P<0.016) for IgG. Conclusions: The RDT was more sensitive than the traditional IFA for the early diagnosis of scrub typhus and was particularly suitable for use in rural areas.
  - 5,001 379
Occurrence and molecular characterization of enteropathogenic Escherichia coli serotypes isolated from children with diarrhoea in Najaf, Iraq
Samer A Al Hilali, Ali M Almohana
October-December 2011, 29(4):383-388
DOI:10.4103/0255-0857.90171  PMID:22120799
Purpose: Enteropathogenic Escherichia coli (EPEC) are among the most important pathogens infecting children worldwide and are one of the main causes of diarrhoea. The study was carried out to investigate the occurrence of EPEC as a cause of infectious diarrhoea in children younger than 2 years of age and characterize their virulence genes. Materials and Methods: During the study period, a total of 656 faecal specimens from children with diarrhoea and 54 from healthy children were analyzed. E. coli isolates were serotypically identified with EPEC polyvalent and monovalent antisera. The isolated EPEC were examined for the presence of the attaching and effacing (eaeA), bundle-forming pilus (bfpA), Shiga like toxins (stx1 and stx2 ), enterohaemorrhagic E. coli enterohaemolysin (EHEC hlyA) and EPEC adherence factor (EAF) genes by the PCR assay. Results: The study has shown that 22 (3.4%) had diarrhoea due to EPEC, while no EPEC isolates were detected in asymptomatic children. The highest number of the EPEC isolated belonging to polyvalent 2. The primers encoding virulence genes were subjected to all the EPEC isolates. Only 9.1%, 27.3%, and 9.1% isolates gave positive re sults with intimin (eaeA), bfbA and (EAF) genes, respectively. None of the isolates were positive for stx 1, stx 2, and hlyA genes. Typical EPEC (eaeA +, bfpA +) was diagnosed in two isolates, while, atypical EPEC was manifested in four isolates. Conclusions: According to the results, the frequency of EPEC isolates in Najaf was lower than what has been suspected and the investigation including the use of molecular technique and serotyping, are necessary to allow precise identification and epidemiological study of these pathogens.
  - 3,382 210
Evaluation of a dry format reagent for CD4+ and CD8+ T-cell enumeration with FACSCount and Guava polymerase chain reaction
J Sachithanandham, K Solomon, S Prasannakumar, G Nithyandham, R Kannangai
October-December 2011, 29(4):401-405
DOI:10.4103/0255-0857.90176  PMID:22120802
Purpose: In all CD4+/CD8+ T-cell estimation systems, the reagents used are liquid in nature and have to be transported and stored at 2°-8°C. This causes problems in countries where the ambient temperature is high for most parts of the year or where the laboratories are at remote places. Materials and Methods: We evaluated a dry format of CD4/CD8 reagents from ReaMetrix (Bangalore, India) against the existing liquid reagents from Becton Dickinson (San Jose, CA, USA) and Guava PCA system (Guava Technologies, Hayward, CA, USA). Blood samples collected during March 2009 through May 2009 from 102 HIV-infected individuals and 31 normal healthy individuals in a tertiary care centre in India (south) were tested by Guava; EasyCD4™ System (PCA) and FACSCount using the respective reagents and the corresponding ReaMetrix reagents. Results: Overall, the correlation (r) of the new Rea T Count and FACSCount reagents for the CD4+ T-cell estimation was 0.98, while with ReaPan 3 4 G reagent in the Guava PCA system with the Guava reagent was 0.97. The mean bias for CD4+ T-cell measurements between Rea T count and BD reagent was -6 cells/ml, while the same with ReaPan 3 4 G reagent in the Guava PCA system was 78 cells/ml. The mean bias for the Rea T count and the ReaPan 3 4 G reagent tested in the FACSCount and Guava PCA system was 17 cells. Conclusions: The dry reagents were found to be reliable and cheaper compared to the existing liquid reagents. This allows the transportation of reagents in the absence of cold chain and will facilitate a more user-friendly CD4+ T-cell testing system.
  - 2,269 159
Standardization of fungal polymerase chain reaction for the early diagnosis of invasive fungal infection
P Deshpande, A Shetty, A Mehta, F Kapadia, A Hedge, R Soman, C Rodrigues
October-December 2011, 29(4):406-410
DOI:10.4103/0255-0857.90179  PMID:22120803
Background: An early initiation of antifungal therapy in invasive fungal infections (IFIs) is critical in reducing the high mortality rate. Current diagnosis of fungal infection relies on microscopy, culture, antigen, antibody specific tests and histological diagnosis. However, these tests either lack sensitivity or specificity. There is thus the need for a rapid, specific and accurate diagnostic method. Objective: The aim of our study was to establish PCR for the rapid detection of Candida and Aspergillus species in clinical specimens with improved sensitivity and specificity. Materials and Methods: A total of 71 proven cases of IFI (confirmed by culture) were collected. A total of 15 healthy, 15 patients suffering from bacterial sepsis and 15 patients with HIV, HBV viral infections were included as controls. Clinical specimens were subjected to a standardized nested amplification to produce Round I (504 bp) and Round II (150 bp) amplicons. Restriction digestion was performed on these products for further identification. Results: Analytical sensitivity was determined using 10 6 -10 CFU/ml of cell suspension. The lower detection limit of the assay was 10 CFU/ml of blood. This test was 100% sensitive and specific with a positive predictive value of 100% and a negative predictive value of 96.7%. Conclusion: The assay was found to be effective for the rapid detection of Candida and Aspergillus in clinical specimens.
  - 4,183 341
Research snippets
P Desikan
October-December 2011, 29(4):450-451
  - 1,322 101
Ethical issues in microbiology
P Desikan, A Chakrabarti, V Muthuswamy
October-December 2011, 29(4):327-330
DOI:10.4103/0255-0857.90154  PMID:22120789
Ethical issues facing microbiologists could be considered in two parts. The first relates to the way the ethical issues during their laboratory work. The second pertains to ethical issues on the data/reports they generate for the patients or in research. In both segments, there is pressure to perform, which is exerted by both, the community, as well as peers. It has therefore become increasingly necessary to recognize the facts that unethical actions might be a frequent reality. Since some of these activities generate serious ethical concerns, both in practice and research, it is necessary for microbiologists to be aware and equipped to meet these issues in a prepared and measured way.. In an attempt to highlight this requirement, this article outlines the important ethical issues and guidelines relevant to the field of Microbiology.
  - 10,169 667
Ethics in biotechnology and biosecurity
S Jameel
October-December 2011, 29(4):331-335
DOI:10.4103/0255-0857.90155  PMID:22120790
Great advances in technology produce unique challenges. Every technology also has a dual use, which needs to be understood and managed to extract maximum benefits for mankind and the development of civilization. The achievements of physicists in the mid-20th century resulted in the nuclear technology, which gave us the destructive power of the atomic bomb as also a source of energy. Towards the later part of the 20th century, information technology empowered us with fast, easy and cheap access to information, but also led to intrusions into our privacy. Today, biotechnology is yielding life- saving and life-enhancing advances at a fast pace. But, the same tools can also give rise to fiercely destructive forces. How do we construct a security regime for biology? What have we learnt from the management of earlier technological advances? How much information should be in the public domain? Should biology, or more broadly science, be regulated? Who should regulate it? These and many other ethical questions need to be addressed.
  - 5,419 277
Bacterial identification in the diagnostic laboratory: How much is enough?
BN Kootallur, CP Thangavelu, M Mani
October-December 2011, 29(4):336-340
DOI:10.4103/0255-0857.90156  PMID:22120791
The major impetus for bacterial identification came after the advent of solid culture media. Morphological appearance of bacterial colonies was often sufficient for their identification in the laboratory. Even in modern times, preliminary identification of most cultivable bacteria is based on such morphological characters. Advances have been made media for the presumptive identifi cation of common organisms encountered in clinical samples. Phenotypic characterisation of bacteria with, physiological tests with a battery of biochemical tests differentiate related bacterial genera as well as confirm their identity. . Each laboratory can select its own method(s) of identification, provided they are based on scientific / epidemiological evidence; clinical laboratory and standards institute (CLSI) is a widely accepted organization and laboratories in many parts of the world follow its recommendations for bacterial identification. Some of the latest advances in identification include Matrix Assisted Laser Desorption Ionization - Time of Flight Mass Spectroscopy (MALDI-TOF) is a state of art facility used for fast and reliable species-specific identification of bacteria including Mycobacteria and fungi including yeasts. However the single most important factor that decides the method of bacterial identification in any laboratory is the cost involved. In the final analysis, selection of tests for bacterial identification should be based on their standardization with proper scientific basis. Considering the cost and lack of easy availability of commercial kits, we have put forward a simplified and rapid method of identification for most commonly encountered bacterial pathogens causing human infection in India
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2004 - Indian Journal of Medical Microbiology
Published by Wolters Kluwer - Medknow

Online since April 2001, new site since 1st August '04