Concurrent Infection of Orientia Tsutsugamushi with Rickettsia spp. Including Rickettsia felis in North Central Bangladesh.

Rickettsial diseases are one of the leading causes of treatable acute febrile illness in Asia pacific region. This cross-sectional descriptive study was conducted at Department of Microbiology, Mymensingh Medical College to diagnose scrub typhus by rapid Immunochromatographic Test (ICT) and Nested PCR followed by molecular identification of possible Rickettsial coinfection among suspected febrile patients in Mymensingh, Bangladesh from March 2019 to February 2020. Among the enrolled 402 patients, 89 samples (22.13%) were seropositive by Immunochromatographic Test (ICT) and 65 samples (16.16%) were positive for O. tsutsugamushi DNA by Nested PCR, targeting 47KDa gene. Therefore, 113/402 (28.10%) samples were positive for scrub typhus by PCR and/or ICT. All the scrub typhus positive samples were further subjected to Nested PCR targeting 17 KDa gene for identification of Rickettsial co-infection and 13/113 (11.50%) were documented as positive. Then 13 Rickettsial co-infected samples were undertaken to automate sequencing and all were genetically confirmed as Rickettsia felis. Findings of the study may help clinicians to expand their list of differential diagnoses for undifferentiated fever and detection of Rickettsial co-infection may guide them to prescribe effective antimicrobials.

Detection of Biocide Resistance Genes (qacE and qacΔE1) in Pseudomonas spp Isolated from Patients with CSOM at Mymensingh Medical College Hospital, Bangladesh.

Biocides, including disinfectants and antiseptics, are used for a variety of topical and hard surface applications in health care facilities. Biocides play a significant role for preventing and controlling nosocomial infections. However, failures in the antimicrobial activities of biocides have been reported. The resistance mechanism to disinfectants is usually determined by genes which are related to resistance to quaternary ammonium compounds, namely, qacE, qacΔE1 that are found in Gram-negative bacteria. The aim of this study is to detect the prevalence of Biocides resistance genes, qacE and qacΔE1, in clinical isolates of Pseudomonas spp. It was carried out from March 2017 to July 2018 in the department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh. Samples were collected from Outpatient of ENT department, MMCH. In this study, 300 clinical samples of CSOM cases were tested by the PCR method. The present study shows detection of biocide resistance genes (qacE, qacΔE1) among 87 isolated Pseudomonas spp by uniplex PCR. Among 72 clinical isolates of Pseudomonas aeruginosa 67(93.05%) had the gene qacEΔ1 and 25(34.72%) had the gene qacE. In addition other 15 Pseudomonas spp 3(20%) isolates had the qacEΔ1 gene and 2(13.33%) isolates had the qacE gene. In this study there is a marked difference in detection of the qacEΔ1 gene between the MDR and non MDR P. aeruginosa isolates. The qacEΔ1 was identified in 50 of 54(92.59%) MDR isolates and 7 of 18(38.89%) non MDR strains respectively. While gene qacE was detect 25(46.29%) MDR isolates and did not show any qacEΔ1gene in non MDR isolates. This study shows that the genes, qacE, qacΔE1 are widespread among Pseudomonas aeruginosa, they are higher in MDR strains than non MDR strains.

Rapid Serologic and Molecular Diagnosis of Scrub Typhus among Suspected Febrile Patients Visiting Mymensingh Medical College Hospital.

Scrub typhus, caused by the bacterium- Orientia tsutsugamushi is one of the leading causes of undifferentiated treatable febrile illness in Asia pacific region. It is grossly under diagnosed in many tropical countries of South Asia including Bangladesh, due to wide range of non-specific clinical presentations, low index of suspicion among clinicians, limited awareness and lack of accurate diagnostic facilities. This cross-sectional descriptive study was conducted at Department of Microbiology, Mymensingh Medical College to diagnose scrub typhus by rapid Immunochromatographic test (ICT) as well as molecular detection of O. tsutsugamushi by Nested PCR and automated nucleotide sequencing among suspected febrile patients in Mymensingh, Bangladesh during 2019-20. Blood samples were collected from 402 febrile patients of suspected Rickettsial illness, referred from inpatient and outpatient departments of Medicine and Pediatrics, Mymensingh Medical College Hospital (MMCH). Among the enrolled 402 patients, 89 samples (22.13%) were seropositive by Immunochromatographic test (ICT) and 65 samples (16.16%) were positive for O. tsutsugamushi DNA by Nested PCR, targeting 47KDa gene. Therefore, 113/402 (28.10%) samples were positive for scrub typhus by PCR and/ or ICT. Highest number of patients was detected positive by nested PCR during the first 5-10 days of fever but only 2 cases were positive after 20 days. In case of ICT, highest positivity for only IgM (8.13%) and both antibodies (2.43%) were documented in first 5-10 days of fever, but IgG positivity was highest (41.66) in >20 days of fever. From 65 PCR positive samples, automated nucleotide sequencing was performed on 20 randomly selected samples and all were genetically confirmed to be O. tsutsugamushi.

Early and Rapid Detection of Typhoid Fever by Nested PCR in Blood.

Typhoid fever caused by Salmonella typhi is one of the major health problems in developing countries including Bangladesh. Still now blood culture is gold standard method for diagnosing typhoid fever, but this method is laborious, requires several days and detection rate is low. Failure of early laboratory diagnosis often leads to increased morbidity and mortality. This study was intended to apply a nested PCR in blood for early diagnosis of typhoid fever. In this cross sectional study blood samples were collected from 200 suspected typhoid fever patients attending Mymensingh Medical College Hospital, Bangladesh. Nested Polymerase Chain Reaction (n PCR) of flagellin gene was done in all the blood samples. At the same time all blood samples were subjected to culture by lytic centrifugation method. Culture positive isolates were identified as S. typhi by biochemical tests. Among the 200 blood samples, 57 (28.5%) were positive for S. typhi on nested PCR where as blood culture was positive for S. typhi in 16 (8%) samples. Among the 57 PCR positive samples, only 15 (26.3%) samples were culture positive for S. typhi and rest 42 (73.7%) were culture negative. So, in culture negative cases PCR can be used as a rapid diagnostic test for diagnosing typhoid fever. Considering time requirement, PCR takes one day, whereas blood culture takes 3 or more days to confirm diagnosis.

Detection of Antimicrobial Resistance Pattern and ESBL Production among Clinical Isolates of Salmonella Species in Mymensingh, Bangladesh.

The occurrence of antimicrobial resistance in Salmonella enterica serovars (both typhoidal and non-typhoidal Salmonellae) is a major public health problem especially in developing countries, which have been associated with treatment failures. Therefore, the study was undertaken to determine the current antimicrobial resistance pattern and extended spectrum ß-lactamase (ESBL) production among clinical isolates of Salmonella spp. during 2019-2020 in Mymensingh, Bangladesh. In this cross sectional study, 36 Salmonella enterica isolates were obtained from blood and stool culture of suspected 200 enteric fever and 100 gastroenteritis patients attending at Mymensingh Medical College Hospital, Mymensingh, Bangladesh. Isolated Salmonella species were identified by biochemical tests and Polymerase Chain Reaction (PCR). Disk diffusion test was performed by modified Kirby Bauer method. Minimum Inhibitory Concentration (MIC) of ceftriaxone was detected by agar dilution method. Double disk synergy test was used as a screening test for ESBL production. PCR was done for detection of blaTEM, blaSHV and blaCTX-MU genes. The isolates showed 25% resistance to Ceftriaxone and 58.3% to Azithromycin. The highest sensitivity rates were 88.9% to Meropenem and 83.3% to Amikacin. Whereas 6(16.7%) isolates were Multi Drug Resistant (MDR). Eight (8) isolates were confirmed as ESBL producer by DDST. The marked increase in MIC was observed between 8->512µg/ml to ceftriaxone. blaTEM, blaSHV and blaCTX-MU genes were detected in 3, 5 and 8 isolates respectively. In conclusion, the current study observed, higher level of resistance to ceftriaxone and azithromycin. At the same times 22.2% isolates showed ESBL production, which is a cause for concern as it may lead to treatment failure. On the other hand the study also showed the re-emergence of chloramphenicol and Sulfamethoxazole-Trimethoprim sensitivity.

Biomanagement of rice root-knot nematode Meloidogyne graminicola using five indigenous microbial isolates under pot and field trials.

AIMS: To ascertain the effectiveness of Aspergillus niger, Trichoderma harzianum, Pochonia chlamydosporia, Bacillus subtilis and Pseudomonas fluorescens against rice root-knot nematode, Meloidogyne graminicola, and to optimize their application methods. METHODS AND RESULTS: The relative effectiveness of five indigenous biocontrol agents (BCA) against M. graminicola on rice cv. PS-5 was tested initially in pot culture. The BCAs, A. niger, P. chlamydosporia and P. fluorescens proved more effective, and significantly reduced the nematode disease. It is hypothesized that success of a biocontrol module may vary with the BCA and application methods. Hence, the effectiveness of the above three BCAs as well as seven different treatment schemes were evaluated in naturally infested farmer's fields during 2 consecutive years. In nematode-infested plots without any BCA treatments, terminal galls formed on the roots, and plants suffered a 19-31% decrease in the growth and yield. The treatments with P. chlamydosporia or A. niger through root-dip (RD) plus one soil application (SA) at 15 days after planting were found to be highly effective against the nematode. CONCLUSIONS: Relatively greater nematode control was achieved with RD plus two SAs (15 + 30 DAP) but statistically the effect was on par with RD + one SA at 15 DAP. These treatments significantly reduced galling (22-25%), egg mass production (21-29%) and reproduction factor (63-70%) of M. graminicola, and subsequently increased the grain yield (11-21%). SIGNIFICANCE AND IMPACT OF THE STUDY: Application methods enhanced the effectiveness of BCAs against M. graminicola. The RD plus one SA at 15 DAP proved to be most effective treatment to control root-knot disease in rice. Use of multiple treatments (root dip and SA) appears cumbersome, but in view of effectiveness and limitation of chemical control in rice paddies, farmers may adopt the above module that may lead to 11-21% yield improvement.