Molecular characterization of colistin-resistant Klebsiella pneumoniae & its clonal relationship among Indian isolates

Background & objectives: Klebsiella pneumoniae (KP), a common cause of invasive infections, is often extensively drug resistant in India. At present, studies on resistance mechanism and clonal relationship of KP from India are limited. The present study was undertaken to determine the resistance mechanism and clonal relationship of colistin-resistant isolates obtained from various specimens. Carbapenemases were also determined since the isolates were carbapenem resistant. Methods: Sixty five isolates from blood, exudates and respiratory specimens collected between 2016 and 2017 were studied. Colistin minimum inhibitory concentration (MIC) was performed by broth-micro dilution method. Multiplex PCR was carried out to determine carbapenemases. Targeted sequencing was performed to determine mutations in mgrB, phoP, phoQ and multilocus sequence typing was performed to determine the prevalent clones. Results: Colistin MIC ranged from 4 to 256 ?g/ml. SHV, TEM and CTX-M were co-produced in 60 per cent and OXA48-like in 71 per cent. Thirteen isolates had mutations in mgrB. Mutations included a premature stop codon at 21st amino acid, the presence of insertion sequences such as IS903, IS Kpn 14 and ISK pn 26; and elongation of mgrB. Novel mutations were also observed among phoP and phoQ genes. Colistin resistance due to mcr genes was absent. Fifteen clonal types were seen with ST231, ST14 and ST2096 being predominant. Interpretation & conclusions: This study revealed the changing trend of carbapenem resistance mechanism predominantly to OXA48-like from NDM. Known mgrB mutations and novel mutations in phoP and phoQ were detected. There was no plasmid-mediated colistin resistance. ST14 and ST231 were international clones associated with carbapenem resistance. Colistin-resistant KP was of diverse clones with predominantly ST231, ST14 and ST2096.

Platelet aggregation and lipid profile in offsprings of young ischemics.

OBJECTIVE: To study the platelet aggregation and lipid profile in offsprings of young ischemic parents. DESIGN: Cross sectional. SETTING: Hospital based. METHODS: 40 adults under 45 years of age with proven CHD and their 50 offsprings comprised the study group. In the control group, 40 age matched adults with normal maximal treadmill test and their 50 off springs were included. All were screened for lipid profile and platelet aggregation. RESULTS: Platelet aggregation was significantly elevated in adults with CHD (44.0 +/- 15.5%) compared to controls (32.22 +/- 9.1%). Children of CHD adults also had significantly elevated aggregation (34.9 +/- 12.5%) compared to control offsprings (27.8 +/- 9.9%). Adult CHD subjects had significantly elevated serum cholesterol, LDL-cholesterol (LDL-C) and atherogenic index compared to control adults. The children in both groups had similar lipid profiles. CONCLUSION: Platelet aggregation is enhanced in offsprings of young ischemics. The potential of this index as a marker for early development of CHD needs to be explored.

Lipid profile norms in Indian children.

OBJECTIVES: To evaluate the lipid parameters in normal Indian children. DESIGN: Cross-sectional. SETTING: Hospital based. METHODS: 410 children (siblings of hospitalized pediatric cases) between 3-12 years were evaluated for total plasma cholesterol (TC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-C). The low density lipoprotein cholesterol (LDL-C) levels were derived from the above parameters using Fredrickson-Friedwald formula. RESULTS: No significant difference was found between the sexes in any of the lipid parameters studied. The mean values were: TC-134.5 mg/ dl, TG-91.1 mg/dl, HDL-C-34.15 mg/dl and LDL-C-80.1 mg/dl. The suggested cut off limits for these parameters were 190 mg/dl, 150 mg/dl, 20 mg/dl and 130 mg/d respectively. CONCLUSIONS: Lipid profile norms and cut off levels to define abnormalities for Indian children were recommended. The HDL-C levels were lower than western data.