Asian Pacific Journal of Tropical Medicine

320-329

Authors: Meghan Tipre, Paul Vijay Kingsley, Tamika Smith, Mark Leader, Nalini Sathiakumar

Objective: To conduct an epidemiological and clinical review of published case reports of melioidosis from India and Bangladesh. Methods: Data from published case reports were abstracted and summarized. We further compared the clinical epidemiology of the melioidosis cases in India with case series from highly endemic areas in Northern Australia and Southeast Asia to elucidate any differences in presentations and risk factors between the regions. Results: We identified a total of 99 cases published between 1953 and June 2016, originating from India (n=85) or Bangladesh (n=14). Cases were predominantly male and ranged in age from 1 month to 90 years. Diabetes mellitus was the most common risk factor reported (58%). About 28% of the cases had history of exposure via high-risk occupations or exposure to contaminated water. The overall case fatality rate (CFR) was 26%. Factors influencing mortality included the occurrence of septic shock (CFR, 80%), environmental exposure (CFR, 39%), primary presentation of pneumonia (CFR, 38%), misdiagnosed and/or mistreated cases (CFR, 33%) or the presence of a risk factor (CFR, 29%). Because of the small number of cases in Bangladesh, pattern of clinical epidemiology is limited to India. Soft tissue abscess (37%) was the most common clinical presentation reported from India followed by pneumonia (24%) and osteomyelitis/septic arthritis (18%). Neurological melioidosis (n=10, 12%) presented as pyemic lesions of the brain or meninges. A few cases of prostatic abscess (n=4) in men and parotid abscess (n=4) were also noted. The above patterns were consistent with case series from Southeast Asia and Northern Australia for the most part, in terms of risk factors associated with infection and factors influencing mortality. Differences included clinical presentation of pneumonia which was notably lower than that reported in Southeast Asia and Northern Australia; a higher proportion of neurological and parotid abscess presentation; and a lower CFR compared to that reported in case series in Southeast Asia. About 39% of the cases were misdiagnosed and/or mistreated, suggesting underreporting and under estimation of the true disease burden. Conclusions: The concentration of melioidosis cases in southern and eastern states in India and in Bangladesh, which share climatic conditions and rice farming activities with known endemic areas in Southeast Asia, suggests an endemicity of melioidosis in this region. Thus, increased awareness among healthcare personnel, particularly among clinicians and nurses practicing in rural areas, and improved surveillance through case registries is essential to guide early diagnosis and prompt treatment.

336-341

Authors: Maryam Homayoon, Yahya Tahamtan, Mohammad Kargar, Seyed Mohammad Hossein Hosseini, Abbas Akhavan Sepahy

Objective: To evaluate the effects of Pasteurella multocida (P. multocida) vaccines on the expression and release of antibodies, interleukin (IL)-6 and IL-12 by serum. Methods: Balb/c mice were immunized with two formalin and iron inactivated vaccine doses within 2 weeks. The vaccines were adjuvant with P. multocida A strain, P. multocida B strain and Salmonella typhimurium bacterial DNA (AbDNA, BbDNA and SbDNA for short, respectively). The animals were challenged 4 weeks after immunization. Blood of mice was collected to detect the change of specific antibody, IL-6, and IL-12 using ELISA. Results: The specific antibody and interleukins in the immunized group increased significantly compared to the control mice after vaccination and challenge (P<0.05). The highest release of these cytokines was obtained by P. multocida inactivated with iron and adjuvant with AbDNA at a concentration of 25 μg/mL. The antibody titer peak was 0.447 in mice vaccinated with iron-killed whole-cell antigen adjunct with AbDNA. The time-courses of release showed that bacterial DNA was able to stimulate IL-6 and IL-12 production more than alum (P<0.05). Conclusions: Our findings introduce that bacterial DNA is capable of releasing an immunological response with several cytokines. These indicate that bacterial DNA entrapped with killed P. multocida antigen is a new and effective adjuvant to enhance specific immunity and resistance of animal against the infectious pathogen, which could simplify the development of highly promising strong adjuvant.

350-354

Authors: Tauhidur Rahman Nurunnabi, Shaymaa Al-Majmaie, Ismini Nakouti, Lutfun Nahar, S. M. Mahbubur Rahman, Md. Hossain Sohrab, Md. Morsaline Billah, Fyaz M. D. Ismail, George P Sharples, Satyajit D Sarker

Objective: To isolate and evaluate the antimicrobial activity of the active principle(s) from the ethyl acetate (EtOAc) extract of endophytic fungus Colletotrichum gloeosporioides (C. gloeosporioides) isolated from Sonneratia apetala. Methods: Water agar technique was used to isolate the fungus, and both microscopic and molecular techniques were used for identification of the strain. Potato dextrose broth was used to grow the fungus in large-scale. Reversed-phase preparative HPLC analysis was performed to isolate the major active compound, kojic acid. The EtOAc extract and kojic acid were screened for their antimicrobial activity against two Gram-positive and two Gram-negative bacteria as well as a fungal strain using the resazurin 96-well microtitre plate antimicrobial assay. Results: The fungus C. gloeosporioides was isolated from the leaves of Sonneratia apetala. Initial identification of the fugal isolate was carried out using spore characteristics observed under the microscope. Subsequently, the ITS1-5.8S-ITS2 sequencing was employed for species-level identification of the fungus C. gloeosporioides. Five litres of liquid culture of the fungus produced approximately 610 mg of a mixture of secondary metabolites. Kojic acid (1) was isolated as the main secondary metabolite present in the fungal extract, and the structure was confirmed by 1D, 2D NMR and mass spectrometry. The EtOAc extract and compound 1 exhibited considerable antimicrobial activity against all tested microorganisms. Whilst the minimum inhibitory concentration (MIC) values from the EtOAc extract ranged between 2.4× 10-4 mg/mL and 2.5 mg/mL, those of kojic acid (1) were between 0.125 mg/mL and 1 mg/mL. The EtOAc extract and kojic acid (1) were most active against Pseudomonas aeruginosa (MIC = 2.4×10-4 mg/mL) and Micrococcus luteus (MIC = 0.125 mg/mL), respectively. Conclusions: The results revealed that the endophytic fungus C. gloeosporioides could be a good source of commercially important kojic acid, which exhibited antimicrobial properties.