Manisha DebMandal’s research while affiliated with MGM Medical College and Hospital and other places

Thyme (Thymus vulgaris L.), belonging to the Lamiaceae family, is a well-known spice plant possessing excellent medicinal properties. Thymus vulgaris oil and extract contain thymol, p-cymene, carvacrol, and γ-terpipene as the major components, which show very strong antibacterial, antifungal, and antioxidant activities; thus, T. vulgaris essential oil and extracts retard food spoilage and increase the shelf-life of foods. Thymus vulgaris essential oil is a safe natural preservative for stored foods, and there is less risk of development of antimicrobial resistance because the mixtures of compounds of the plant oil represent different mechanisms of antimicrobial activities. Thyme is generally regarded as safe; however, a spasmodic cough, particularly in young children, may be dangerous. Further research is needed to evaluate the effectiveness of T. vulgaris essential oil in food ecosystems to establish its utility as a natural antimicrobial agent in food preservation and safety.

Fenugreek (Trigonella foenum-graecum L.) is a plant in the family Fabaceae, and its oils and extracts have been known to possess antimicrobial, antioxidant, antidiabetic, and antitumorigenic activities. The plant is commonly cultivated in India, Egypt, the Middle East, and North Africa and has been widely used as an ingredient in traditional medicine. The T. foenum-graecum galactomannan acts as a gum and an emulsifier, and hence can be used as a stabilizer as well as thickening agent for food. Its strong flavor and aroma lead fenugreek to be used as spice and flavoring agent in food preparation. The antibacterial, antifungal, antioxidant, and antispoilage activities of fenugreek oils and extracts are attributed to a variety of its constituents, as discussed in this chapter, based upon the scientific reports, in different Web-based journals, related to food preparation and preservation in order to maintain food quality and shelf life of foods.

Objective To evaluate the applicability of nalidixic acid (Nx) resistance in determining reduced susceptibility to ciprofloxacin (Cp) among Salmonella enterica serovar Typhi (S. Typhi) clinical isolates.Methods The correlation between Cp MIC (minimum inhibitory concentration) values and that Nx, and between Cp MICs and zone diameter of inhibition (ZDI) around 30-μg Nx disc for 421 S. Typhi isolates were determined by scattergram analysis. The specificity and sensitivity, in determining Cp reduced-susceptibility, of Nx resistance by disk testing and MIC determination were calculated.ResultsFor the test S. Typhi isolates the simultaneous presence of Nx-resistance and decreased Cp susceptibility has been recorded. The Nx sensitive S. Typhi isolates were sensitive to Cp; the disc diffusion and MIC breakpoints cannot determine Cp resistance. The sensitivity of Nx disc was 100 %, and the specificity was 89.20 % in determining Cp reduced-susceptibility of S. Typhi isolates; when MICs of Nx were compared with MICs of Cp, the sensitivity and specificity of the approach were 100 % and 95.95 %, respectively.Conclusion Association between Nx-resistance and reduced susceptibility to Cp was noticed (P ≤ 0.001) among the S. Typhi isolates, and thus Nx-resistance might be an indication of decreased susceptibility to Cp.

Objective To develop an approach for making a selective and differential media specific for Lactobacillus rhamnosus Goldin and Gorbach (LGG) in order to distinguish it from other bacterial flora in fecal samples.Methods The current media referred as LGGM has been prepared by using MRS media ingredients (replacing dextrose with 2% sorbitol), and incorporation of nalidixic acid (40 μg/mL), bromocresol purple (0.002 %); the pH of the media was adjusted to 4.5.ResultsThe LGGM showed a greater colony forming units compared to MRS media. The growth of pure LGG strain was significantly greater in LGGM, and the recovery rate of LGG released from fecal samples (after oral feeding) was significantly greater (P<0.001).Conclusions Thus LGGM could be used as a potential media for the isolation and identification of LGG strain.

This communication states the changing patterns of Salmonella enterica serovar Typhi (S. Typhi) isolates causing enteric fever in and around Kolkata, India. Among the isolates resistance to ampicillin (A), chloramphenicol (C), cotrimoxazole (Co) and tetracycline (T) were plasmid mediated; the plasmid was unstable in S. Typhi, and the other enteric bacteria like Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were found to be the potential source of dissemination of such plasmids into S. Typhi. The infection with such S. Typhi strains were successfully treated with ciprofloxacin (Cp: MICs 0.0075-0.075 μg mL⁻¹) and/or ofloxacin (Ofx: MICs 0.0125-0.075 μg mL⁻¹), but in the later course, the S. Typhi strains, showing resistance to nalidixic acid, developed low level of resistance to Cp and Ofx, causing the treatment failure. Thus, the treatment regimen was shifted to the third generation cephalosporins like ceftriaxone (Ct) and cefotaxime (Cf). Keeping in mind the anticipation of development of resistance to Ct/Cf, we prepared the treatment regimen for MDR enteric fever, based on the double-drug synergy tests in vitro; Cp-gentamycin (FICI 0.121-0.216) and Cp-trimethoprim (FICI 0.14-0.483) combinations were found effective against S. Typhi isolates having decreased sensitivity to cp (MICs: 0.5-1.25 μg mL⁻¹).

The present study investigates the prevalence of antibiotic resistance among bacterial isolates from different environmental samples and determines their resistance patterns. Bacteria were isolated from the Ganges water, the intestine of Labeo rohita, soil samples from agricultural land, and clinical samples of urine, pus, and throat swab. The bacterial isolates were identified on the basis of standard cultural, morphological and biochemical characteristics. Antibiotic susceptibility of the isolates was tested by disc diffusion and agar dilution method. A total of 87 bacteria belonging to 13 different genera were isolated. The percentages of resistance detected were, Ax: amoxycillin (82.75%), Te: tetracycline (49.42%), Tr: trimethoprim (41.37%), Ch: chloramphenicol (39.08%), Nx: nalidixic acid (22.98%), Ci: ciprofloxacin (24.13%), S: streptomycin (9.19%), G: gentamycin (4.59%) and Ak: amikacin (4.59%). A majority of 57 (65.51%) strains were multi-resistant; 77 (88.5%) were resistant to at least one drug. Determination of resistance pattern revealed that 3 water isolates and 1 clinical isolate belonging to Pseudomonas aeruginosa (n=3) and Proteus vulgaris (n=1) were resistant to all the 9 antibiotics tested; a Proteus mirabilis strain was resistant to all the drugs except G. In the seven-drug-resistant group, Klebsiella aerogenes showed AxChTeNxTSCi-resistance and P. mirabilis strain exhibited AxChTeNxTrGCi resistance pattern. The high prevalence of antibiotic-resistant bacteria harboring diverse resistance traits could represent a potential health risk. The study of antibiotic resistance helps predict future emergence and guide the development of strategies to counteract this resistance. Therefore periodic and comprehensive survey of antibiotic resistance in the environmental bacteria is required.

To investigate the prevalence of leptospirosis among patients from within and outside Kolkata, India, attending the Calcutta School of Tropical Medicine, for treatment during August 2002 to August 2008. The leptospirosis cases were determined on the basis of clinical, epidemiological, and biochemical factors, and were tested for leptospiral antibodies using IgM ELISA. Serum samples with absorbance ratio ≥ 1.21 were interpreted as reactive. The commonest presentation involved fever, headache and jaundice. The male-female ratio was 61:46. A total of 65(64.20%) cases had abnormal liver and renal functions respectively, and 57.1% had both the abnormalities. The highest incidence (75, 35.04%) was recorded in September-October followed by July-August (53, 24.77%). The reactive cases had absorbance ratios between 1.21 and 8.21, and 53 showed equivocal result, while IgM non reactivity were seen in 90 patients (absorbance ratios 0.10-0.90). The patients responded to treatment with parenteral antibiotics, penicillin, ceftriaxone and cefotaxime; follow up did not reveal case fatality. The cardinal signs of leptospirosis help in making clinical diagnosis, but in any hyper-endemic situation any patient reporting with acute fever and signs of pulmonary, hepatic or renal involvement should be suspected to have leptospirosis and investigated accordingly. Increased awareness, and early diagnosis and treatment, can reduce mortality due to leptospirosis.

Objective To determine the incidence of leptospiral jaundice and find the correlation among human leptospiral cases with or without jaundice.Methods Patients suspected for leptospirosis, attending Calcutta School of Tropical Medicine, Kolkata, India during 2002 to 2008 were evaluated as per modified Faine's criterion.ResultsOut of 404 suspected cases, 214 were found positive for leptospirosis, 15 were jaundice positive but without leptospirosis and 175 cases had neither leptospirosis nor jaundice. Serum bilirubin and creatinine levels among leptospirosis patients were (1.89-42.70 mg/dL) and (0.60-6.40 mg/dL), respectively; serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) were (99.00-410.00 U/L) and (57.00-887.00 U/L), respectively; IgM values by ELISA were (0.63-3.28 U/mL).Conclusions There is no association between occurrence of jaundice and leptospirosis and it also does not confirm the expected 1:1 ratio of jaundice and leptospirosis (P<0.005).

The present study is an investigation on the kinetics of dimethoate biodegradation and an estimation of residual dimethoate in bacterial culture by spectrophotometry. The methylene chloride extract of the culture medium was used for determination of dimethoate through its reaction with 1 chloro-2, 4 dinitrobenzene to produce methylamine whose absorbance at 505 nm gave an estimation of dimethoate con-tent. The dimethoate standard curve follows Beer's law at 505 nm with a slope of 0.0129 absorbance units per µg/mL. The regression equation relating concentration of dimethoate (x) with the absorbance is (y): y = 0.037+ 0.0129x. The amount of residual dimethoate after 7 days were 0, 4, 17, 28 and 29 µg/mL; the rate constants were 0.775, 0.305, 0.225, 0.167 and 0.127 each per day, and the efficiency of dimethoate degradation were 100%, 96%, 83%, 72% and 71%, for Bacillus licheniformis, Pseudomonas aeruginosa, Aeromonas hydrophila, Proteus mirabilis and Bacillus pumilus respectively. Dimethoate remediation could be attained through bacterial metabo-lism of the pesticide and colorimetric analysis might be useful in the estimation of dimethoate within a detection limit of 5-100 µg/mL.

Coconut, Cocos nucifera L., is a tree that is cultivated for its multiple utilities, mainly for its nutritional and medicinal values. The various products of coconut include tender coconut water, copra, coconut oil, raw kernel, coconut cake, coconut toddy, coconut shell and wood based products, coconut leaves, coir pith etc. Its all parts are used in someway or another in the daily life of the people in the traditional coconut growing areas. It is the unique source of various natural products for the development of medicines against various diseases and also for the development of industrial products. The parts of its fruit like coconut kernel and tender coconut water have numerous medicinal properties such as antibacterial, antifungal, antiviral, antiparasitic, antidermatophytic, antioxidant, hypoglycemic, hepatoprotective, immunostimulant. Coconut water and coconut kernel contain microminerals and nutrients, which are essential to human health, and hence coconut is used as food by the peoples in the globe, mainly in the tropical countries. The coconut palm is, therefore, eulogised as 'Kalpavriksha' (the all giving tree) in Indian classics, and thus the current review describes the facts and phenomena related to its use in health and disease prevention.