Enhancing chloramphenicol and trimethoprim in vitro activity by Ocimum sanctum Linn. (Lamiaceae) leaf extract against Salmonella enterica serovar Typhi

OBJECTIVE@#To evaluate the antibacterial activity of Ocimum sanctum (O. sanctum) leaf extract, alone, and in combination with chloramphenicol (C) and trimethoprim (Tm) against Salmonella enterica serovar Typhi (S. typhi).@*METHODS@#The antibacterial activity of ethanolic extract of tulsi, O. sanctum, leaf (TLE; 500 μg) for 23 S. typhi isolates was determined following agar diffusion. The C (30 μg) and Tm (5 μg) activity alone and in combination with TLE (250 μg) was determined by disk diffusion. The zone diameter of inhibition (ZDI) for the agents was recorded, and growth inhibitory indices (GIIs) were calculated.@*RESULTS@#The S. typhi isolates (n=23), which were resistant to both C (ZDI 6 mm) and Tm (ZDI 6 mm), had TLE (500 μg) ZDIs 16-24 mm. The ZDIs of C and Tm were increased up to 15-21 mm and 17-23 mm, respectively, when TLE (250 μg) was added to the C and Tm discs. The GIIs ranged 0.789-1.235 and 0.894-1.352, due to combined activity against S. typhi isolates, of C and TLE and Tm and TLE, respectively.@*CONCLUSIONS@#The data suggest that TLE, in combination with C and Tm, had synergistic activity for S. typhi isolates, and hence O. sanctum is potential in combating S. typhi drug resistance, as well promising in the development of non-antibiotic drug for S. typhi infection.

vitro antibacterial activity of three Indian spices against methicillin-resistan staphylococcus aureus

To explore the in vitro antibacterial activity of ethanolic extracts of cinnamon [Cinnamomum zeylanicum; CIN], clove [Syzygium aromaticum, CLV] and cumin [Cuminum cyminum, CMN] against clinical isolates of methicillin resistant Staphylococcus aureus [MRSA], from Kolkata, India. The CIN, CLV and CMN were tested for their antibacterial activity against MRSA by in vitro methods. Minimum inhibitory concentration [MIC] values of the three extracts were determined, and time-kill studies were performed in order to investigate the bactericidal activity of the extracts [at the MIC level] for the isolates. The killing efficacy of the extracts was determined at various concentrations. The zone diameter of inhibition [ZDI] obtained due to CIN, CLV and CMN ranged between 22-27 mm, 19-23 mm and 9-15 mm, respectively; while the MICs, for the isolates, were in the range of 64-256, 64-512 and 128-512 microg/ml, respectively. When tested for their MIC levels; the CIN and CLV were found to be bactericidal after 6 hrs of incubation, while CMN showed bactericidal activity after 24 hrs. However, when tested at various concentrations; CIN, CLV and CMN displayed bactericidal activity against S. aureus, after 24 hrs of incubation, at 200, 200 and 300 microg/ml, respectively. The C. zeylanicum and S. aromaticum showed the strongest in vitro antibacterial activity followed by C. cyminum against MRSA, and such findings could be considered a valuable support in the treatment of infection and may contribute to the development of potential antimicrobial agents for inclusion in anti- S. aureus regimens

Serologic evidence of human leptospirosis in and around Kolkata, India: a clinico-epidemiological study

OBJECTIVE@#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.@*METHODS@#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.@*RESULTS@#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.@*CONCLUSIONS@#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.

Cholera: a great global concern

Cholera, caused by the infection of toxigenic Vibrio cholerae (V. cholerae) to humans, is a life threatening diarrheal disease with epidemic and pandemic potential. The V. cholerae, both O1 and O139 serogroups, produce a potent enterotoxin (cholera toxin) responsible for the lethal symptoms of the disease. The O1 serogroup has two biotypes (phenotypes), classical and El Tor; each of which has two major serotypes (based on antigenic responses), Ogawa and Inaba and the extremely rare Hikojima. V. cholerae O1 strains interconvert and switch between the Ogawa and Inaba serotypes. Fluid and electrolyte replacement is the mainstay of treatment of cholera patients; the severe cases require antibiotic treatment to reduce the duration of illness and replacement of fluid intake. The antibiotic therapy currently has faced difficulties due to the rapid emergence and spread of multidrug resistant V. cholerae causing several outbreaks in the globe. Currently, cholera has been becoming endemic in an increasing number of geographical areas, reflecting a failure in implementation of control measures. However, the current safe oral vaccines lower the number of resistant infections and could thus represent an effective intervention measure to control antibiotic resistance in cholera. Overall, the priorities for cholera control remain public health interventions through improved drinking water, sanitation, surveillance and access to health care facilities, and further development of safe, effective and appropriate vaccines. Thus, this review describes the facts and phenomena related to the disease cholera, which is still a great threat mainly to the developing countries, and hence a grave global concern too.