Deciphering polymyxin B minimum inhibitory concentration from colistin minimum inhibitory concentration and vice versa: An analysis on 156 carbapenem-resistant Enterobacteriaceae isolates

The susceptibility determination to polymyxins (colistin and polymyxin B) remains a challenge for clinical microbiology laboratories. We evaluated the minimum inhibitory concentration (MIC) of both antimicrobials by the broth microdilution method in a selected subset of 156 carbapenem-resistant Enterobacteriaceae (CRE) isolates. Good concordance between polymyxin B and colistin MIC values was obtained, and there was 98% categorical agreement in CRE isolates. Future large-scale multicentre study is needed to draw conclusion if the MIC of colistin can be used to extrapolate the MIC of polymyxin B and vice versa.

HLA-DQA1 & DQB1 variants associated with hepatitis B virus-related chronic hepatitis, cirrhosis & hepatocellular carcinoma

Background & objectives: Clinical outcome after hepatitis B virus (HBV) exposure varies extremely from spontaneous clearance to chronic hepatitis B and often progresses to liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Host genetic factor plays an important role in the regulation of immune response. This study was aimed to investigate whether HLA class II DQA1 and DQB1 gene polymorphism were associated with chronic hepatitis B infection and in the development of HBV-related LC and HCC. Methods: DQA1 and DQB1 allele polymorphism were studied in 187 patients with HBV-related liver diseases (which included 73 chronic hepatitis B, 84 LC and 30 HCC patients) and 109 controls who had spontaneously recovered from HBV infection using polymerase chain reaction amplification with sequence-specific primers. Results: Our data suggested that DQA1*0101/2/4 [odds ratio (OR)=2.78; Pc=0.003], DQA1*0103 (OR=2.64; Pc=0.0007) and DQB1*0302/3 (OR=2.15; Pc=0.01) were associated with the protection from chronic HBV infection, whereas DQB1*0402 (OR=0.25; Pc=0.001) showed susceptible effect on chronic HBV infection. DQB1*0601 (OR=3.73; Pc=0.006) conferred protective effect from developing LC; similarly, DQB1*0302/3 (OR=5.53; Pc=0.05) and DQB1*0402 (OR=0.00; Pc=0.001) conferred protective effect from developing HCC. However, DQA1*0601 and DQB1*0503 showed susceptible effect on chronic HBV infection; these associations were no longer significant after Bonferroni correction. Interpretation & conclusions: Our results revealed HLA-DQA1*0101/2/4 - DQA1*0103 - DQB1*0302/3 and DQB1*0601 as protective and DQB1*0402 as risk alleles. The study suggests that various subtypes of HLA-DQA1 and DQB1 are associated with both HBV clearance and development of chronic HBV infections.

Expression analysis of apolipoproteins AI & AIV in hepatocellular carcinoma: A protein-based hepatocellular carcinoma-associated study

Background & objectives: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality. The objective of this study was to find out the differential expression of apolipoproteins (ApoAI and ApoAIV) in HCC and cases of liver cirrhosis and chronic hepatitis (controls) without HCC and to compare ApoAI and ApoAIV expression with alpha-foetoprotein (AFP), the conventional marker in HCC. Methods: Fifty patients with HCC and 50 controls comprising patients with liver cirrhosis (n=25) and chronic hepatitis (n=25) without HCC were included in this study. Total proteins were precipitated using acetone precipitation method followed by albumin and IgG depletion of precipitated protein using depletion kit. Proteins were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The expression changes of ApoAI and ApoAIV were confirmed by western blotting using specific primary and secondary polyclonal antibodies followed by densitometric protein semi-quantitative estimation. ApoAI, ApoAIV and AFP were measured in the plasma samples by ELISA method. Results: Semi-quantitative densitometric image analysis of the western blot images and the comparison between HCC patients with those without HCC (control) revealed differential expression of ApoAI and ApoAIV. Levels of ApoAI were significantly higher in patients with HCC compared to controls without HCC (0.279�216 vs 0.171�091 and 0.199�014; P <0.001). Levels of ApoAIV were significantly lower in patients of HCC compared to controls without HCC (0.119�061 vs 0.208�07 and 0.171�16; P <0.01). ELISA assays of apolipoproteins (ApoAI and ApoAIV) revealed similar results of expression of ApoAI and ApoAIV as detected in western blotting densitometric image analysis. Interpretation & conclusions: Increased expression of ApoAI and decreased expression of ApoAIV in HCC patients compared to controls without HCC revealed the abnormalities in HCC. These molecules need to be studied further for their use as potential biomarkers in the future diagnostic tools along with other conventional biomarkers for screening of HCC cases. It needs further analysis in higher number of patient population.

Promoter region polymorphism & expression profile of toll like receptor-3 (TLR-3) gene in chronic hepatitis C virus (HCV) patients from India.

Background & objectives: Hepatitis C virus (HCV) induces an immune response of the host, manifested by the formation of anti-HCV antibodies mediated by adaptive and innate immunity. Toll-like receptors (TLRs) play a pivotal role in innate immunity system. This study was aimed to investigate the promoter region polymorphism and expression of TLR3 gene in patients with chronic HCV infection. Methods: Patients with chronic HCV infection (N=180) and an equal number of age-sex matched controls were included in the study. Patients positive for HCV-RNA were subjected to analysis of TLR3 polymorphism by direct sequencing of PCR products verified by comparing with the sequences reported in the National Centre for Biotechnology Information (NCBI) database (accession number: NT 022792). Expression of TLR3 gene was analyzed by semiquantitative RT-PCR using housekeeping β-actin gene as the internal control. Results: Polymorphisms at position -288G/A and -705A/G were identified. The results were significant in -705 allele (P=0.004) OR 2.79(1.46-5.42) and were associated with high risk of HCV infection. In silico sequence analysis showed the presence of ectropic viral integration site 1 encoded factor, in which G at -705 results in the loss of this site. The -7C/A polymorphism was not seen in our study cohort. The expression of TLR3 was upregulated in chronic HCV patients compared to healthy controls. Interpretation & conclusions: Polymorphism in the -705A/G allele at the promoter region of the TLR3 gene may predispose individual to HCV infection. However association of TLR3 expression with polymorphism of TLR3 promoter was not found.

Significance of anti-HBc screening of blood donors & its association with occult hepatitis B virus infection: Implications for blood transfusion.

Background & objective: Expansions of blood donor screening and improved laboratory detection of viral markers have remarkably reduced the risk for infection with transfusion-transmitted viruses. This study was aimed to evaluate the presence of anti-HBc and to determine the presence or absence of HBV DNA in the serum samples from HBsAg negative, anti-HBc positive blood donors in a tertiary care hospital blood bank from Delhi. Methods: A total of 2175 HBsAg negative, first time volunteer blood donors were included in the study from blood bank, Lok Nayak Hospital, New Delhi. The blood specimens from all these subjects were evaluated for anti-HBV-core antigen (anti-HBc) serology, anti-HBV-surface antigen (anti-HBs) titres and HBeAg. The presence of HBV DNA was evaluated by testing, through polymerase chain reaction (PCR) techniques. Results: Of the 2175 HBsAg negative voluntary blood donors, 413 (19.8%) were tested to be positive for anti-HBc alone. Of these, 153 (group-I) were anti-HBs negative whereas group-II comprises a total of 260 anti-HBs positive cases i.e. 89 out of 413 had anti-HBs titres of 10-99 IU/l and the remaining 171 had anti-HBs titres of 100-500 IU/l. HBV DNA was detected in 7.5 per cent anti-HBc positive samples irrespective of anti-HBs status. Interpretation & conclusions: Our results showed that 18.9 per cent of our donor population was anti-HBc reactive, and hence inclusion of anti-HBc testing will lead to a high discard rate. The presence of HBV DNA in fairly high percentage of anti-HBc positive samples highlighted the need for a stringent and better screening system to prevent occult HBV infection.

Clinical & molecular characterization of human TT virus in different liver diseases.

Background & objectives: TT virus (TTV) is a newly discovered non-enveloped, single stranded DNA virus of high genotypic variability, found frequently in patients with acute or chronic hepatitis of non A-G aetiology. This study was carried out to look for the presence of TTV and its genotypes in patients with different types of liver diseases from northern India. Methods: A total of 262 serum samples from patients of acute viral hepatitis (AVH; n=72), fulminant hepatic failure (FHF; n=49), chronic active hepatitis (CAH; n=93) and liver cirrhosis (LC; n=48), were analyzed for hepatitis A-G viral markers. TTV DNA was detected in all cases by nested polymerase chain reaction (PCR) using the primers from N22 and untranslated (UTR) region. TTV-DNA was also tested in 150 volunteer blood donors. Direct nucleotide sequencing of N22 amplicons were carried out to look into the prevalent TTV genotypes. Results: TTV-DNA was detected in 73.6, 59.2, 21.5 and 29.1 per cent cases with AVH, FHF, CAH and cirrhosis, respectively. In AVH and FHF groups, TTV showed co-infection with all A-G hepatitis cases whereas in CAH and cirrhosis groups, TTV co-infection observed with HBV, HCV and HGV. TTV-DNA was detected in 45.3 per cent volunteer blood donors. No statistically significant difference was observed amongst the mean liver function profile of UTR PCR positive and negative cases in different liver disease groups except AVH cases, in whom the various biochemical parameters between TTV positive and TTV negative patients were marginally significant. However, no significant evidence of biochemical or histological deterioration of the liver was observed in TTV positive cases amongst FHF, CAH and cirrhosis. Predominance of genotype 1a was observed in all the cases from north India. Interpretation & conclusions: TTV is a frequent virus isolated from patients with various types of liver diseases as well as in healthy individuals from northern India. TTV has no effect on biochemical markers of associated liver diseases. Genotype 1a was the most predominant type in different liver disease groups. The occurrence of TTV did not further influence the course of the disease.

Seroprevalence of subclinical HEV infection in pregnant women from north India: A hospital based study.

Background & objectives: Hepatitis E virus (HEV) is a major public health problem in the developing countries. HEV infection in pregnant women is more common and fatal in the third trimester. The mortality rate due to HEV-induced hepatitis is as high as 15-20 per cent. The present study was designed to determine the seroprevalence of subclinical HEV infection in pregnant primigravidae women. Methods: A total of 300 asymptomatic healthy primigravidae (gestational age 16-24 wk) with no history of jaundice were included in the study. Prevalence of anti-HEV antibodies was determined by an enzyme linked immunosorbent assay (ELISA) kit. Results: The overall prevalence of seropositive HEV IgG was 33.67 per cent among the pregnant women. The seropositivity of HEV IgG was significantly high in urban population (P<0.05), and related with the period of settlement (P<0.05) and source of water (P=0.05). Low socio-economic status of the pregnant women appeared to be the only risk factor (OR=1.96, CI=1.17-3.28) associated with HEV IgG antibody. Interpretation & conclusions: In the present study, exposure to HEV during pregnancy was higher in urban (slum areas) than rural population. Socio-economic status was a risk factor for anti-HEV IgG in pregnant women. Early preventive measures if taken, may decrease the maternal and perinatal mortality and morbidity of HEV infection.

Prevalence & risk factors for hepatitis C virus among pregnant women.

BACKGROUND & OBJECTIVE: Information on hepatitis C virus (HCV) infection in pregnant women in India is scanty. This study was carried out to investigate the prevalence of HCV within an obstetric population in north India and to identify the various risk factors for the viral infection. METHODS: A total of 8130 pregnant women from antenatal clinic were subjected to anti-HCV testing by third generation ELISA. Anti-HCV positive seropositive women were further tested for HCVRNA, hepatitis B and HIV. The women were evaluated for the presence of following known risk factors for HCV infection. RESULTS: Eighty four (1.03%) pregnant females had HCV antibodies. Of these, 46 (54.8%) were positive for HCV-RNA, 4(4.8%) tested positive for HBsAg, while none tested positive for HIV. The mean age and parity of the anti-HCV antibody positive women was 24.36+/-3.6 yr and 0.9+/-0.8, while that of the anti-HCV antibody negative women was 24.13+/-3.6 yr and 0.8+/-0.8 respectively. Of the 84 anti-HCV positive women, 52 (61.9 %) did not have any identifiable risk factors. The risk factors variables did not have significant association with HCV positive status. INTERPRETATION & CONCLUSION: Prevalence of hepatitis C in pregnant women was 1.03 per cent. None of the known risk factors was found to be significantly associated with the HCV infection. Hence case identification and consequent management pose a particular problem and routine screening is not a viable option in our resource- poor setting.

Occurrence & nucleotide sequence analysis of hepatitis G virus in patients with acute viral hepatitis & fulminant hepatitis.

BACKGROUND & OBJECTIVE: Association of hepatitis G virus (HGV) with acute viral hepatitis (AVH) and fulminant hepatitis (FH) is not clearly understood.This study was designed to asses the occurrence of HGV infection and its relationship with other hepatotropic viruses in patients with FH and AVH and also to determine the nucleotide sequence of HGV isolates. METHODS: The study included 100 patients of FH and 125 of AVH on the basis of clinical examination, liver function test and serology for hepatitis A, B, C and E virus. HGV RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and direct sequencing for 4 randomly selected samples followed by phylogenetic analysis. RESULTS: Of the 100 patients with FH, 30 were negative for hepatitis viruses A, B, C and E by serology (non A-non E) while 60 were negative in the AVH group. In the non A-non-E hepatitis group, HGV was positive in 16.66 per cent (5/30) cases of FH, 10 per cent (6/60) cases of AVH and 6 per cent (6/100) of healthy controls. The difference in HGV seropositivity between FH and AVH patients was statistically not significant compared to healthy controls, while HBV and HCV infections were significant. The four isolates sequenced seemed to be of same type and close to Chinese strain of HGV (Y13755.1 Y13756.1 Y15407, and U67782) on phylogeny. INTERPRETATION & CONCLUSION: In HGV infection was not found to be clinically significant as well as nonpathogenic in the patients of FH and AVH and appeared to be an innocent bystander in the course of the disease. The four sequenced HGV isolates showed close pairing with Chinese strains.

Seroprevalence of hepatitis C virus (HCV) in health care workers of a tertiary care centre in New Delhi.

Hepatitis C virus (HCV) is a parenterally transmitted virus that poses an occupational hazard to the health care workers (HCWs). No significant data are available regarding the prevalence of HCV in health care workers in India. The present study was designed to determine the seroprevalence of HCV infection in health care workers in a tertiary care centre in New Delhi. The subjects (n=100) were divided according to the duration of employment and the unit where they were working. Blood samples were collected from all the subjects and sera were tested for anti-HCV antibodies. The seroprevalence of anti-HCV was found to be 4 per cent. The duration of occupational exposure was not a significant risk factor for HCV infection and prevalence of anti-HCV antibodies were highest in HCWs working in haemodialysis units. The seroprevalence of HCV in health care workers was considerably higher than that reported in the general population, and needs to be evaluated on a larger sample.

Two cases of subungual glomus tumor.

Glomus tumors are uncommon, small, painful, and usually benign hamartomas arising from the arterial end of the glomus body. They often present early in the subungual stage because of intense pain. Two female patients with subungual glomus tumor are reported here. The intense pain associated with this tumor had led to disuse atrophy of the upper limb in one case. Hildreth's sign and Love's test were positive in both, but imaging did not help in preoperative diagnosis. Tumors were resected by transungual approach, leaving a 3-mm-wide margin. There was no recurrence after 1-year follow-up in both instances.