Distribution of Virulence Genes among Enterococcus species Isolated from Patients of Urinary Tract Infection Attended in a Tertiary Care Hospital of Bangladesh

Enterococcus species was frequently considered to be commensal organisms but last few decades it has emerged as an important cause of health care associated infections. The presence of virulent genes is one of a key factor for which Enterococcus spp. is gaining attention. In this study, we aim to determine the frequency of virulence genes in uropathogenic Enterococcus species. A total of 46 Enterococcus strains isolated from January 2017 to December 2017. Urine samples were collected from adult clinically suspected urinary tract infected patients from the inpatient and outpatient department of Dhaka Medical College Hospital, Bangladesh irrespective of sex and antibiotic intake. Potential virulence genes such as asa, esp, ace, ebp, cyl, gelE, pilA, pilB, sprE, scm, fms8, ecbA and hyl were detected by PCR using specific primers. Among 46 culture positive Enterococcus, 33(71.74%) were E. faecalis, 11(23.91%) were E. faecium, 2(4.35%) were unidentified. Of the 44 identified Enterococci (33 E. faecalis and 11 E. faecium), 43(97.73%) were positive for pilB, 41(93.18%) for both scm and fms8, 39(88.64%) were positive for ebp, 34(77.27%) for gelE, 32(72.78%) for esp, 31(70.45%) for ecbA, 30(68.18%) for sprE, 28(63.67%) for pilA, 25(56.82%) for ace, 21(47.73%) for cyl, 20(45.45%) for asa and 3(6.82%) for hyl gene. Different virulence factors could be associated with the pathogenicity of E. faecalis and E. faecium and these genes are extensively available among the Enterococcus species.

Detection of Quinolone resistance Qnr genes and its association with Extended Spectrum β-lactamase and AmpC β-lactamase genes in Qnr Positive Enterobacteriaceae in Bangladesh

This cross-sectional study was conducted to explore quinolone resistant Enterobacteriaceae followed by searching the prevalence of three groups of quinolone resistance genes (QnrA, QnrB and QnrS) from January 2015 to December 2015 at Dhaka Medical College hospital, Bangladesh. Then genes for ESBL and AmpC β-lactamase were detected among Qnr positive strains for better understanding the role of these genes for multiple drug resistance. Total 340 urines, sputum, wound swab and blood samples were collected from DMCH. Total 270(79.41%) Enterobacteriaceae were isolated from 340 samples. Out of 270 Enterobacteriaceae, 225(83.33%) were quinolone (ciprofloxacin) resistant strains. Qnr genes were detected in 141(62.67%) of the 225 quinolone resistant Enterobacteriaceae. Total 187 Qnr genes [84(59.57%) QnrS, 70(49.64%) QnrB and 33(23.40%) QnrA] were detected from 141 quinolone resistant strains. Total 48(34.04%) ESBL producers were detected by DDS test and 47(33.33%) ESBL producers were positive by PCR among 141 Qnr positive strains. QnrA was co-existed with CTX-M-15. QnrB was co-existed with TEM, CTXM-15 and OXA-1. QnrS genes were also associated with TEM, CTX-M-15 and OXA-1. Among 52 cefoxitin resistant Qnr positive strains, 22(42.31%) AmpC β-lactamase producers were detected by Modified three-dimensional test (MTDT) and 45(86.54%) AmpC β-lactamase producers were detected by PCR. QnrA had been identified with DHA, ACC, EBC and CIT while QnrB had been identified with DHA, ACC, EBC and CIT. QnrS had also been co-existed with DHA, ACC, EBC and CIT. The results of this study provided insights into the high proportion of Qnr genes among isolated Enterobacteriaceae. Simultaneous presence of Qnr genes and genes for extended-spectrum β-lactamase or AmpC β-lactamase were observed in multidrug resistant Enterobacteriaceae.

Postoperative wound infection by nontuberculous mycobacteria; case series in Dhaka Medical College Hospital of Bangladesh

The incidence of nontuberculous mycobacterial (NTM) infections after operations is increasing in Bangladesh but data regarding clinical presentation, diagnosis, treatment, and prognosis after treatment are lacking. In this case series, three patients having persistent serous discharge from incision wound after operation were studied. Discharge from wounds were collected, wet film microscopy was performed for pus cells and fungus, Gram stain, Ziehl-Neelsen (ZN) stain, culture in routine culture media and Lowenstein-Jensen (LJ) media, Xene-Xpert for mycobacterium tuberculosis (MTB), polymerase chain reaction (PCR) for NTM were done. NTM-positive patients were treated initially for 6 weeks with four drugs regimen (clarithromycin 500 mg 12 hourly, ciprofloxacin 500 mg 12 hourly, linezolid 400 mg 12 hourly, and amikacin 500 mg 12 hourly), followed by 5 months with three drugs regimen (clarithromycin 500 mg 12 hourly, ciprofloxacin 500 mg 12 hourly, and linezolid 400 mg 12 hourly) as a maintenance dose. Cessation of discharge occurred within 3-4 weeks after starting treatment, and the wounds were healed.

Carbapenem Resistance among Klebsiella pneumoniae in a Tertiary Care Hospital in Bangladesh

Carbapenem-resistant K pneumoniae (CRKP) clinical isolates have spread widely now-a-days throughout the world. This study was designed to investigate the carbapenem resistance among Klebsiella pneumoniae and to see anitimicrobial susceptibility of these CRKP isolates to other antimicrobials in a tertiary care hospital in Bangladesh. K pneumoniae was detected by standard methods and various biochemical tests like Triple Sugar Iron (TSI) agar media, Simmons citrate agar media and Motility-Indole-Urea (MIU) agar media. Imipenem resistance was used as the indicator for carbapenem resistance. Agar dilution method was used to determine MIC of imipenem. CRKP were tested for their antimicrobial susceptibility by Kirby-Bauer modified disc-diffusion technique as per Clinical and Laboratory Standard Institute (CLSI) guidelines and United States Food and Drug Administration (FDA) guidelines. Total 75 K pneumoniae were isolated. Among the isolated K pneumoniae, 28(37.33%) were resistant to carbapenem. Most of the CRKP were recovered from intensive care unit. MIC of CRKP ranged from ≥32μg/ml to ≤4μg/ml. Most of the CRKP were resistant to other antimicrobials. Carbapenem resistance in K pneumoniae is increasing in Bangladesh, which is very alarming and we should give importance on standard guideline of antimicrobials use.

Distribution of Ciprofloxacin- and Azithromycin-Resistant Genes among Salmonella Typhi Isolated from Human Blood

Context

Salmonella Typhi has developed resistance to different groups of antibiotics.

Aims

The purpose of the present study was to assess the distribution of ciprofloxacin- and azithromycin-resistant genes among Salmonella Typhi isolated from human blood.

Settings and Design

This cross-sectional study was conducted in the Department of Microbiology of a tertiary care hospital in Bangladesh from July 2019-June 2020.

Subjects and Methods

Clinically suspected enteric fever patients, irrespective of age and gender, who attended the laboratory of the Department of Microbiology and outpatient department of Medicine of tertiary care hospital. Blood culture and sensitivity tests were done. The positive growth of Salmonella Typhi was identified by Gram staining, colony morphology, and biochemical test. Then, Salmonella Typhi was identified by using Salmonella-specific antisera. Final identification was made by using 16s rRNA by polymerase chain reaction (PCR). PCR was also done to detect quinolone and azithromycin resistance genes.

Results

A total number of 83 samples yielded positive cultures, of which 50 isolated organisms were identified as Salmonella species; however, among these isolates, Salmonella Typhi was detected in 40 (48.2%) isolates. Among 12 ciprofloxacin-resistant isolates, 8 (66.67%) were positive for the gyrA gene, 1 (8.33%) was positive for the qnrB gene and qnrS gene, 2 (16.67%) were positive for aac (6´)-Ib-cr. Among 12 azithromycin-resistant isolates, 2 (16.66%) were positive for mphA and mefA genes, respectively.

Conclusion

In conclusion, the gyrA, aac (6´)-Ib-cr, mphA, and mefA genes are found for the first time in tertiary care hospitals from the quinolones and azithromycin-resistant Salmonella Typhi.

Prevalence of Colistin Resistance in Klebsiella pneumoniae Isolated from a Tertiary Care Hospital in Bangladesh and Molecular Characterization of Colistin Resistance Genes among Them by Polymerase Chain Reaction and Sequencing

Resistance to colistin, the last resort of treatment for multidrug resistant organisms has increased now-a-days. This cross-sectional study was conducted in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh, from July 2016 to June 2017 and was designed to investigate the colistin resistance profile along with the genetic background of colistin resistance among Klebsiella pneumoniae in a tertiary care hospital in Bangladesh. K. pneumoniae was detected by colony morphology on culture media and various biochemical tests. Agar dilution method was used to determine MIC of colistin. PCR was done for detection of colistin resistance genes and sequencing of the amplified mgr B gene products was done. Total 75(23.73%) K. pneumoniae were isolated. Among the isolated K. pneumoniae, 8(10.67%) were resistant to colistin. MIC of colistin of resistant isolates ranged from ≥64μg/ml to ≤4μg/ml. Out of 8 colistin resistant K. pneumoniae, 4(50.00%) were positive for mgr B gene and 3(37.50%) were positive for pho Q gene. Colistin resistance in K. pneumoniae is increasing in Bangladesh, which is very alarming and we should give importance on standard guideline of antimicrobials use.

Identification of Genes Encoding Aminoglycoside Modifying Enzymes among Clinical Isolates of Proteus species at a Tertiary Care Hospital in Dhaka, Bangladesh

Proteus is considered as one of the major opportunistic pathogens liable for nosocomial infections and acquired several resistances to a wide range of antimicrobials such as aminoglycosides. The most common mechanism of aminoglycoside resistance is the inactivation of drugs by modifying enzymes. So, this cross-sectional study was undertaken to investigate the occurrence of aminoglycoside resistance and identify aminoglycoside modifying enzyme (AME) genes among clinical isolates of aminoglycoside resistant Proteus spp. A total of 40 Proteusmirabilis and Proteus vulgaris were isolated in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh from July 2018 to June 2019 of 500 wound swab & pus, urine and blood samples. Disk diffusion test was performed by modified Kirby Bauer method. Minimum inhibitory concentration (MIC) of amikacin was determined by agar dilution method. PCR was used to detect aac(3)-Ia, aac(6')-Ib, ant(4')-IIa, ant(2'')-Ia a and aph(3'')-Ib AMEs genes among aminoglycoside resistant Proteus spp. Sequencing of aac(6')-Ib gene was performed to identify aac(6')-Ib-cr variant. Thirty-two (80%) aminoglycoside resistant isolates were detected during disk-diffusion technique. The marked increase in MIC was observed between 256 - ≥2048μg/ml to amikacin. The most prevalent AME-genes were aac(6')-Ib (37.5%), ant(2'')-Iaa (21.86) followed by ant(4')-IIa(12.5%), aph(3'')-Ib (12.5%) andaac(3)-Ia (9.38%). The most frequent combination was aac(6')-Ib + aac(3)-Ia+ant(2'')-Iaa and aac(6')-Ib + ant(4')-IIa + aph(3'')-Ib(2 strains) followed by aac(6')-Ib + aac(3)-Ia(1 strain). Sequencing of aac(6')-Ib gene in this study did not harbor aac(6')-Ib-cr variant gene. The results of this study provide insight into the presence of high AME-genes among Proteus spp. in Bangladesh.

Association of virulence with antimicrobial resistance among Klebsiella pneumoniae Isolated from hospital settings in Bangladesh

Introduction:

Infections caused by multidrug-resistant (MDR) hypervirulent Klebsiella pneumoniae are difficult to treat and associated with high mortality rates. Hence, this study was conducted to determine the antibiotic resistance pattern along with the distribution of virulence genes among isolated string test positive and negative strains.

Materials and Methods:

A total of 44 K. pneumoniae strains were isolated following standard microbiological methods from 350 different clinical samples from patients admitted to Dhaka Medical College Hospital, Bangladesh. String test was done to detect the hypermucoid phenotype. Antimicrobial resistance (AMR) pattern was determined by dichlorodiphenyltrichloroethane (except colistin and fosfomycin) among all isolates. Polymerase chain reaction was done to detect the hypervirulence genes (magA, rmpA, rmpA2 iutA, iroN).

Results:

In this study, 21/44 (47.73%) of the isolated K. pneumoniae were string test positive and distribution of the virulence genes except rmpA2 was higher among them. A total of 15/44 (34.09%) of the isolated K. pneumoniae were MDR, 10/44 (22.73%) were extensively drug resistant, 1/44 (2.27%) was pan drug resistant, and 14/44 (31.82%) were colistin resistant. Isolated organisms were highly resistant to third-generation cephalosporins and most sensitive to fosfomycin in this study. Although all the string test positive strains showed higher resistance rates than the string test negative ones toward most of the tested antibiotics, only the differences of resistance rates to amoxiclav and tigecycline among the two phenotypes were statistically significant.

Conclusion:

Our findings highlight the importance of surveillance of the AMR pattern of hypervirulent K. pneumoniae in clinical samples. Therefore, a response to check the global dissemination of this hypervirulent K. pneumoniae with resistance determinants is urgently needed.

Prevalence of qnr and aac(6')-Ib-cr Genes in Clinical Isolates of Proteus spp. at a Tertiary Care Hospital in Dhaka, Bangladesh

Plasmid mediated quinolone resistance (PMQR) has been revealed to play not only a significant role in quinolone resistance but also this drug resistance can spread from one bacterium to another. There is limited data regarding the prevalence of PMQR are available from Bangladesh. So, the aim of this study was to detect the prevalence of qnr and aac(6')-Ib-cr genes among clinical isolates of ciprofloxacin resistant Proteus spp. This cross-sectional study was carried out in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh from July 2018 to June 2019. Fourty (40) Proteus spp. was isolated from 300 culture positive samples. Proteus mirabilis and Proteus vulgaris were identified by culture and biochemical test. Antibiotic susceptibility was performed by disc-diffusion technique. Quinolone resistance genes (qnrA, qnrB, qnrC, qnrD, qnrS and aac(6')-1b-cr) among ciprofloxacin resistant Proteus spp. were detected by PCR. Thirty (75%) ciprofloxacin resistant isolates were detected during disk-diffusion technique. Among them, quinolone resistance genes were found positive 11(36.67%) for aac(6')-Ib-cr, 6(20%) for qnrA, 5(16.67%) for qnrD, 4(13.33%) for qnrS and 3(10%) for qnrB genes. Co-existance of qnrA + aac(6')-Ib-cr and qnrD + qnrS were found in 3(10%) wound swab & pus and urine samples respectively followed by qnrA + qnrB in 2(6.67%) wound swab and pus and qnrA+qnrS in 1(3.33%) urine sample. The results of this study showed presence of high (66.67%) percentage of PMQR genes as well as high (30%) rate of co-carriage of the two genes among Proteus spp. isolates. The incidence of PMQR genes was found to be high which could be due to the increased prescription of fluoroquinolones. Thus, there is a need for rational usage of fluoroquinolones.

Emergence of OXA-833 in Proteus Species at a Tertiary Care Hospital in Dhaka, Bangladesh

CONTEXT

Proteus species are liable for multitude of infections and associated with resistance to routinely used antibiotics even to reserve drugs such as carbapenems.

AIMS

The aim of this study was to detect the presence of MBL producers, including blaOXA-833 gene in Proteus spp. along with their antibiotic resistance pattern.

SETTINGS AND DESIGN

This cross-sectional study was conducted in the Department of Microbiology of a tertiary care hospital of Bangladesh during July 2018 to June 2019.

SUBJECTS AND METHODS

Proteus spp. was isolated from a total of 500 samples. Antibiotic susceptibility was performed by disk-diffusion technique. Minimum inhibitory concentration (MIC) of imipenem was determined by agar dilution method. Carbapenemase producers were phenotypically detected by double disc synergy (DDS) test, combined disc (CD) assay, and modified Hodge test (MHT). Carbapenemase genes (blaKPC, blaVIM, blaIMP, blaNDM-1, blaOXA-23, blaOXA-48-like/blaOXA-833, and blaOXA-58) among imipenem-resistant Proteus spp. were detected by polymerase chain reaction (PCR). Sequencing was performed to differentiate OXA-833 from OXA-48-like gene by capillary method, and the nucleotide sequence of OXA-833 has been deposited to GenBank.

RESULTS

Ten (25%) imipenem-resistant isolates were detected during disk-diffusion technique, among them 60%, 70%, 50% carbapenemase producers were detected by DDS test, CD assay, MHT, respectively, and 70% by PCR. A significant increase in MIC was found between 8 and ≥128 μg/ml to imipenem. PCR revealed that 40% imipenem-resistant isolates were positive for blaNDM-1 and blaVIM followed by 20% for blaOXA-48-like/blaOXA-833 and blaOXA-23, respectively. Sequencing of blaOXA-48-like gene established the OXA-833 variant of class D carbapenemase encoding gene.

CONCLUSION

The results of this study showed the presence of high proportion of carbapenemase enzyme-producing Proteus spp. in Bangladesh. blaOXA-833 is emerging in Bangladesh.

Intradermal Immunization with Heat-Killed Klebsiella pneumoniae Leading to the Production of Protective Immunoglobulin G in BALB/c Mice

Introduction:

Klebsiella pneumoniae superbug is emerging as a serious health concern as resistance to last-resort antibiotics spreads. To bypass the therapeutic molecules used today, the development of an immunoprophylactic safe approach is of great clinical relevance. This study was conducted to determine the protective efficacy of antibodies elicited by killed vaccine against multidrug-resistant (MDR) K. pneumoniae.

Materials and Methods:

In this study, heat-killed MDR K. pneumoniae isolated from different clinical samples were employed for the intradermal immunization of 10 BALB/c mice. Two weeks after the third dose of immunization, the mice were intraperitoneally challenged with live K. pneumoniae and observed for 14 days. Tail blood was collected 7 days after each booster followed by cardiac puncture 14 days postchallenge. Bactericidal activity and antigen-binding capacity of the serum antibody produced by the vaccine were evaluated by serum bactericidal antibody (SBA) assay and ELISA, respectively.

Results:

In this study, 80% survival rates were observed at 14 days postchallenge among the immunized mice. Regarding SBA assay, 100% bactericidal activity of the immunized mouse sera was observed using 50% guinea pig complement at 1:10 serum dilution after 3 h of incubation, and all the pre- and postchallenge immunized serum immunoglobulin G antibody had significantly higher optical density values comparing the control mice in ELISA.

Conclusion:

In our study, intradermal immunization with heat-killed MDR K. pneumoniae produced protective antibodies in BALB/c mice. These findings suggest that the use of a first-generation vaccine provides the supply of a larger number of candidate antigens for eliciting required immune response.

Quick Identification and Differentiation of Proteus spp. by PCR and RFLP Along with Their Antibiotic Resistance Pattern

Different Proteus species are encountered in human infections and may vary with the type of infections they cause. So, the present study was conducted to detect species of Proteus by PCR and RFLP along with their antibiotic resistance pattern. This cross-sectional study was conducted in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh, from July 2018 to June 2019. A total of 500 wound swab and pus, urine and blood samples were tested for bacterial pathogens. Proteus spp. were identified and differentiated by biochemical test, PCR and RFLP. Antibiotic susceptibility was performed by disc-diffusion technique. Fourty Proteus spp. was isolated from 300 culture positive samples, giving 13.33% prevalence of Proteus infections. Proteus mirabilis and Proteus vulgaris were identified by culture, biochemical test, PCR and RFLP. The results were similar by both methods (biochemical tests and PCR). RFLP of 16S rRNA fragments digested with HaeIII revealed that P. mirabilis consisted of two bands at approximately 110 and 190 bp and P. vulgaris consisted of three bands at approximately 100, 180 and 220 bp. The proportion (80%) of P. mirabilis was more than P. vulgaris. Highest proportion (77.5%) of Proteus spp. was isolated from wound swab and pus followed by urine samples. A significant proportion of Proteus spp. was multidrug resistant (90%) and extensively drug resistant (37.5%). Fosfomycin was found the most sensitive drug followed by imipenem. This study provided an insight into antibiotic resistance pattern of Proteus spp. and showed high level resistance towards commonly used antimicrobial agents. PCR and RFLP may be suitable method to identify and differentiate species of Proteus and to treat them accordingly.

Evaluation of Ventilator Associated Respiratory Tract Infections (VARTI) by Common Anaerobic and Atypical Bacteria among the Patients of ICU of a Tertiary Care Hospital in Bangladesh

Background and aim of the study:Ventilator-associated respiratory tract infection (VARTI)is theleading cause of higher mortalityand morbidity in ICU compared to non-ICU patients. Thisarticlereveals etiology of VARTI by commonanaerobic and atypical bacteria in ICU of Dhaka Medical College. Materials and Methodology: This is a cross-sectionalstudy where 200 endotracheal aspirate (ETA)samples were taken from clinically suspected patients of VARTI. After proper screening,bacteria were identified by PCR as because anaerobic and atypical bacteria cannot be easily grown inconventional culture media. Result: Sixty three (31.5%) samples were found to have VARTI. Among the common atypicalbacteriacausing, M. pneumoniae was found in 4 (6.35%) and L. pneumophila in 2 (3.17%) of the 63 samples. Insearch of the anaerobic bacteria causing VARTI,Peptostreptococcus was detected in 3 (4.76%) whileFusobacterium nucleatum andPrevotella melaninogenicawere detected in 2 (3.17%) each of the 63 samples. Conclusion: Anaerobic and atypical bacteria are implicated in VARTI in ICU although at a relative lowrate. JBSA 2021; 34(1): 32-37

Design, Operation and Optimization of Constructed Wetland for Removal of Pollutant

Constructed wetlands (CWs) are affordable and reliable green technologies for the treatment of various types of wastewater. Compared to conventional treatment systems, CWs offer an environmentally friendly approach, are low cost, have fewer operational and maintenance requirements, and have a high potential for being applied in developing countries, particularly in small rural communities. However, the sustainable management and successful application of these systems remain a challenge. Therefore, after briefly providing basic information on wetlands and summarizing the classification and use of current CWs, this study aims to provide and inspire sustainable solutions for the performance and application of CWs by giving a comprehensive review of CWs' application and the recent development of their sustainable design, operation, and optimization for wastewater treatment. To accomplish this objective, thee design and management parameters of CWs, including macrophyte species, media types, water level, hydraulic retention time (HRT), and hydraulic loading rate (HLR), are discussed. Besides these, future research on improving the stability and sustainability of CWs are highlighted. This article provides a tool for researchers and decision-makers for using CWs to treat wastewater in a particular area. This paper presents an aid for informed analysis, decision-making, and communication. The review indicates that major advances in the design, operation, and optimization of CWs have greatly increased contaminant removal efficiencies, and the sustainable application of this treatment system has also been improved.

<p>Observation of Changes in <em>Helicobacter pylori</em> Antigen and Antibody Positivity According to Non-Invasive Tests Before and After <em>Helicobacter pylori</em> Eradication Therapy in Symptomatic Patients</p>

Background

Non-invasive tests can help with the diagnosis of Helicobacter pylori (H. pylori) infection and in determining patient prognosis following H. pylori eradication therapy. The aim of the study was to detect H. pylori antigens in the stool in symptomatic patients and to observe changes in the antigen test results following H. pylori eradication therapy.

Methods

A prospective study was conducted. Blood, urine and stool samples were collected from 62 dyspeptic patients. Anti-H. pylori IgM and IgG antibodies were detected in the serum by ELISA, anti-H. pylori IgG antibodies were detected in the urine by ICT and H. pylori antigens were detected in the stool by ELISA. Among the 62 patients, 39 (62.90%) were positive with all three methods. These 39 patients were asked to complete a 2-week course of medication and return after 6 weeks following completion of therapy to undergo repeated tests. In total, 3 dropped out of the study.

Results

Among the 62 dyspeptic patients, 41 (66.13%) were positive for serum IgG according to ELISA, 39 (62.90%) were positive for urine IgG according to ICT, 8 (12.90%) were positive for serum IgM according to ELISA, and 42 (67.74%) were positive for HpSA according to ELISA. After eradication therapy, 18 (50.00%) patients were positive for serum IgG, 19 (52.78%) were positive for urine IgG, 4 (11.11%) were positive for serum IgM and 5 (13.88%) were positive for HpSA. The difference in HpSA positivity before and after eradication therapy was statistically significant (P <0.05).

Conclusion

This study involved non-invasive procedures that can be used as first-line screening tools for the detection of active H. pylori infection to observe the role of HpSA test in diagnosis and assessment of prognosis following eradication therapy for H. pylori.

Phenotypic and Molecular Characterization of AmpC beta-lactamase Enzyme Producing Escherichia coli and Klebsiella species Isolated from A Tertiary Care Hospital in Bangladesh

This cross-sectional study was conducted to determine the prevalence of AmpC beta-lactamase enzyme producing Escherichia coli and Klebsiella species in a tertiary care hospital of Bangladesh, as well as to observe the patterns of antibiotic resistance and AmpC beta-lactamase resistance genes among them. This study was conducted in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh from January 2015 to December 2015. Total 166 Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca were isolated from urine, wound swab, pus, sputum and blood samples of patients of Dhaka Medical College Hospital. Antibiotic susceptibility test was performed by disk-diffusion technique. AmpC beta-lactamase producers were detected phenotypically by Modified three-dimensional test (MTDT). AmpC beta-lactamase genes (DHA, ACC, EBC, CIT, MOX, FOX) among the cefoxitin resistant Escherichia coli and Klebsiella species were detected by polymerase chain reaction (PCR). Sixty seven cefoxitin resistant Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca were isolated during disk-diffusion technique. Among the 67 cefoxitin resistant strains, 30(44.78%) AmpC beta-lactamase producers were detected by MTDT and 59(88.06%) were detected by PCR. The dominant genotype found was CIT (62.69%) followed by DHA (53.73%). The results of this study showed high proportion of AmpC beta- lactamase enzyme producing Escherichia coli and Klebsiella species in Bangladesh. Regular surveillance of antibiotic resistance should be done in every tertiary care hospital to prevent spread of these strains.

Real Time-PCR (RT-PCR) Positivity for SARS-CoV-2 in Suspected COVID-19 Patients Presented in a Tertiary Care Hospital

Introduction: Corona Virus Disease 2019 (COVID-19) is caused by SARS-CoV-2, a newly emergent virus. World Health Organization declared COVID-19 as pandemic on March 11, 2020 for its rapid spreading. Not only to diagnose the disease (confirm case) but also to control and contain the transmission; test, trace and isolation are fundamental. RT-PCR for SARS-CoV-2 is used to detect and diagnose COVID-19 which started in Dhaka Medical College Hospital (DMCH) on 2nd April 2020. In this study we described our observation of RT-PCR done in patients presented in DMCH in the first month after starting the test. Methods: This observational, cross sectional study was done to find out the rate of RT-PCR positivity in suspected COVID -19 patients presented to DMCH from 2nd April to 3rd May, 2020 by the Department of Medicine in association with the Department of Virology. Data was collected from the registry book of the Department of Virology. The rate of RT-PCR for SARS-CoV-2 positivity among the suspected COVID-19 patients and demographical variable was observed. Results: Among the total studied patients (n=3206), 58.8% (n=1886) was male and mean age was 37.7(±14.38784) years. RT-PCR for SARS- CoV-2 was positive in 26.9% (n=864). Mean age was higher in patients positive for test (39.6± 15.9 year vs. 37±14.4 year). Male predominance was more marked in patients with positive PCR test (68.4 vs. 55.9). Conclusion: High rate of positivity of RT PCR for SARSCoV- 2 among the suspected patient for COVID 19 indicated high disease burden and transmission in this highly populated area in the early period of pandemic which should be considered as was alarming. J Bangladesh Coll Phys Surg 2020; 38(0): 67-70

Nasal Colonization of Methicillin Resistant Staphylococcus aureus among Healthcare Providers in a Tertiary Care Hospital, Bangladesh

Healthcare providers colonized with Staphylococcus aureus may transmit the organism to patients and community. This study was carried out to determine the rate of nasal colonization of Methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Staphylococcus aureus (VRSA) among healthcare providers. This cross sectional study was conducted among healthcare providers in a tertiary care hospital, Bangladesh. Nasal swabs from anterior nares of 250 physicians, nurses, and helping staffs working in Dhaka Medical College Hospital were analyzed. Methicillin resistance among MRSA was detected by disc diffusion technique using oxacillin, cefoxitin disc and MIC of oxacillin and methicillin resistance was confirmed by PCR detecting mec-A gene. Considering PCR for mec-A gene as gold standard the sensitivity and specificity of both cefoxitin disc diffusion method and MIC of oxacillin was 100%. Cefoxitin disc diffusion method was better alternative of oxacillin disc diffusion method for detection of MRSA. Nasal colonization by S. aureus was found among 23.2% healthcare providers and 7.2% were colonized with MRSA and no VRSA was detected. MRSA colonization was detected among 5% physicians, 6.43% nurses and 16.67% of helping staffs. Isolated MRSA strains were highly resistant to ciprofloxacin (88.9%), gentamicin (77.8%), erythromycin (72.2%) and Co-trimoxazole (72.2%). All the isolated MRSA were sensitive to linezolid and vancomycin. Periodic screening of healthcare providers should be done to find out MRSA carrier and should be treated accordingly to terminate chain of transmission of the multi-drug resistant organism.

Laboratory Diagnosis of Bacterial Vaginosis and Potential Pathogens Other Than Group B Streptococcus in Vaginal Swab of Pregnant Women in Dhaka Medical College Hospital

Pathogenic microorganisms are important cause of maternal and neonatal infections which are transmitted from colonized vagina of mother. The purpose of the present study was to detect the potential pathogens other than Group B Streptococcus in vaginal swab of pregnant women. This prospective cross sectional study was conducted from July 2013 to June 2014 at Dhaka Medical College Hospital, Dhaka, Bangladesh. A total of 224 vaginal swab samples were studied. Gram stain Nugent score was applied for all vaginal smear to detect bacterial vaginosis. Organisms were isolated and identified by wet film microscopy, Gram stain, biochemical tests, culture and PCR. Toxic shock syndrome toxin-1 gene and drug resistance genes such as mecA, vanA, vanB were detected among isolated Staphylococcus aureus. Antimicrobial susceptibility was done by disc diffusion method. Double disc synergy test was used to detect ESBL (Extended spectrum beta lactamases) producers. MIC (Minimum inhibitory concentration) of oxacillin and vancomycin were done for Staphylococcus aureus to detect MRSA (Methicillin resistant Staphylococcus aureus) and VRSA (Vancomycin resistant Staphylococcus aureus). Of the 224 samples, 44(19.64%) were Staphylococcus aureus, 22(9.8%) were Escherichia coli. Bacterial vaginosis was found in 12(5.36%) cases. Among the 9(21.43%) phenotypically identified ESBL producers, 4(18.18%) were Escherichia coli, 2(25%) were Klebsiella pneumoniae. Ninety six percent and 91% of the Escherichia coli were sensitive to colistin and imipenem. All the Klebsiella spp. was sensitive to colistin and all the Proteus spp. and the Pseudomonas aeruginosa were sensitive to imipenem and colistin. Of the 44 Staphylococcus aureus, 5(11.36%) were MRSA, 2(4.54%) were VRSA, 2MRSA were PVL gene positive and 2(4.54%) were positive for TSST-1 gene by PCR. All the isolated MRSA and VRSA were sensitive to linezolid. One of the two VRSA strains had MIC of vancomycin 64μg/ml and another had 128μg/ml. VRSA strains were positive for vanB gene, no VRSA was positive for vanA gene. Vaginal ecosystem study with the detection of pathogens can be helpful in the prevention of preterm delivery, premature rupture of membrane, chorioamnionitis, neonatal, puerperal and maternal-fetal infections.

Detection of Virulence Factors and Antimicrobial Resistance in Enterococci Isolated from Urinary Tract Infection

Background: The genus Enterococcus is of increasing significance as a cause of nosocomial infections and this trend is exacerbated by the development of antibiotic resistance.Objective: The aims of this study was to find out the susceptibility pattern and the prevalence of virulence genes in Enterococcus strains isolated from urinary tract infection in Bangladesh.Methodology: This cross-sectional study was conducted in the Department of Microbiology at Dhaka Medical College, Dhaka from January 2015 to December 2015 for a period of one (01) years. All the admitted patients in the Dhaka Medical College & Hospital, Dhaka and Banghabandhu Sheikh Mujib Medical University, Dhaka who were  presented with clinical features of urinary tract infection at any age with both sexes were included as study population. The antimicrobial susceptibility of the strains was determined using the disk diffusion method; vancomycin susceptibility pattern was detected by MIC method. PCR was performed for the detection of genus-species, vanA, vanB gene and potential virulence genes.Result: Out of 84 Enterococci, majority (71.42%) of the isolates were E. faecalis followed by 23.81% were E. faecium. Regarding antimicrobial susceptibility pattern, 100% isolated Enterococci were sensitive to vancomycin, linezolid and teicoplanin. Most of the Enterococci were resistant to ciprofloxacin and ceftriaxone (92.86%) followed by 88.10% to gentamicin and 85.71% to azithromycin and rifampicin. No VRE was identified and the range of MIC for vancomycin was 1-4 µg/ml. None of the Enterococci was positive for vanA and vanB genes. Out of total E. faecalis and E. faecium, 87.50% were positive for ebp and 77.5%, 72.5%, 55.0%, 45.0%, 40.0% and 10.0% of isolates were positive for gelE, esp, ace, cyl, asa and hyl respectively.Conclusion: Almost all the virulence genes were more prevalent in E. faecalis isolates.Bangladesh Journal of Infectious Diseases 2017;4(2):30-34

Detection of Group B Streptococcus in Vaginal Swab of Pregnant Women by Culture and PCR and Their Antibiotic Susceptibility Pattern in a Tertiary Care Hospital of Bangladesh

Group B Streptococcus (GBS) is an important cause of neonatal infection and transmitted from colonized vagina of mother. The purpose of the present study was to see the status of GBS infection in pregnant women. This prospective cross sectional study was conducted from July 2013 to June 2014 at Dhaka Medical College Hospital, Dhaka, Bangladesh. Total 224 vaginal swab samples were studied. Organisms were isolated and identified by Wet film microscopy, Gram stain, biochemical tests, culture and PCR. Of the 224 samples, 46(20.53%) were GBS positive. Highest proportion (33.78%) of GBS was found in 20-29 years of age group. Regarding GBS positivity majority (43.47%) were second gravid, 82.60% in 35-37 weeks of pregnancy, 64.04% were from middle income group, 39.13% were oral contraceptive pill (OCP) users. Hundred percent GBS were sensitive to penicillin, ampicillin, ceftriaxone and vancomycin. Most (46.43%) of the GBS were resistant to gentamycin followed by 35.72% to doxycycline and 28.57% to chloramphenicol. The sensitivity of PCR was 100%. Prevalence of GBS colonization was 20.53% among the pregnant women of Dhaka Medical College Hospital signifies GBS infection might be a silent clinical problem.

Antibiotic Resistance Pattern and Prevalence of Aminoglycoside-Modifying Enzymes in Escherichia Coli and Klebsiella species Isolated from a Tertiary Care Hospital in Bangladesh

This cross-sectional study was conducted in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh, from January 2015 to December 2015 to investigate the antibiotic resistance pattern and prevalence of genes encoding aminoglycoside-modifying enzymes in Escherichia coli and Klebsiella species isolated from a tertiary care hospital of Bangladesh. A total of 166 Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca were isolated from urine, wound swab, pus, sputum and blood samples of patients of Dhaka Medical College Hospital. Antibiotic susceptibility test was performed by disk-diffusion technique. Genes encoding aminoglycoside-modifying enzymes [aac(3)-IIa, aac(6')-Ib, ant(2'')-Ia, aac(3)-Ia] among the isolated Escherichia coli and Klebsiella species were detected by polymerase chain reaction. The most prevalent aminoglycoside-modifying enzyme gene found was aac (3)-IIa (60.24%), followed by aac(6')-Ib (57.23%), ant(2'')-Ia (12.05%) and aac(3)-Ia (10.84%). Colistin and tigecycline were the most effective antibacterial agents against aminoglycoside-modifying enzymes followed by imipenem. The results of this study showed high proportion of aminoglycoside-modifying enzymes producing Escherichia coli and Klebsiella species in Bangladesh.

Identification of Bacterial Isolates from Endotracheal Aspirate of Patients in Intensive Care Unit and Their Antimicrobial Susceptibility Pattern

Background: Nosocomial infections have been discussed as a critical issue among intubated patients leading to significant morbidity and mortality. Tracheal colonization of different bacteria may be responsible for added or superinfections and may increase the risk of mortality. Irrational use of antibiotics also increases the emergence of drug-resistant bacteria.Objectives: We aimed to investigate the bacterial isolates in the endotracheal aspirates of ICU patients and to see the pattern of antibiotic susceptibility.Materials and Methods: This cross-sectional study was based on 40 specimens of endotracheal aspirates which were collected from ICU patients of Dhaka Medical College Hospital. All the specimens were processed and cultured on MacConkey and blood agar media. The isolated organisms were identified by different biochemical tests.Results: Among the 40 specimens, 38 (95%) yielded growths of different bacteria. Of them, Acinetobacter baumanni were 13 (34%), Pseudomonas aeruginosa were 6 (16%), Klebsiella pneumoniae were 3 (8%), Klebsiella oxytoca were 3 (8%) and Staphylococcus aureus were 3 (8%). All the isolated bacteria were sensitive to colistin and most of the Acinetobacter baumanni were resistant to different antibiotics. Among the 32 isolated gram-negative bacteria, 10 (31.25%) were ESBL producers.Conclusion: Most of the bacteria showed antibiotic resistance to different common antibiotics, which is very alarming for the ICU patients.J Enam Med Col 2018; 8(2): 67-73

Molecular characterization and resistance profile of nosocomial Acinetobacter baumannii intensive care unit of tertiary care hospital in Bangladesh

This study was designed to investigate the resistance profile along with the genetic background of resistance to beta-lactam antibiotics among the nosocomial A. baumannii in Bangladesh. A. baumannii was confirmed by detecting blaoXA-51-like. Antibiotic susceptibility was determined by disk diffusion method. Agar dilution method was used to determine MIC of ceftazidime and imipenem. All A. baumannii were phenotypically screened for ampC, ESBL and MBL production. Genetic markers of antibiotic resistance. such as blaampC, blaOXA-51, 23, 40, 58 and 143, blaKPc, blaMp, blavi and blaNDM-j, genetic environment around blaADc and ISAbal upstream of blaoXA, were evaluated by PCR. Twenty-four (96%) A. baumannii were considered as MDR. 96% A. baumanii were resistant to amoxiclav, ceftazidime, ciprofloxacin and cefoxitin, 92% to cefotaxime and piperacillin-tazobactam, 88% to cefepime, amikacin and imipenem, 52% to sulbactam- cefoperazone and 40% were resistant to aztreonam. Everything were sensitive to colistin. The distribution of several beta-lactamase genes such as blaoxa-51 (100%), blaADC-like (92%), blaNDM-i (92%), EBC group (84%), blaoxa-23 (76%), blavm (72%), blacpc (44%), DHA group (24%), blaoxa-58 (16%), ACC group (8%) and CIT group (4%) were observed among the 25 A. baumannii. This is the first reported plasmid mediated ampC beta-lactamases in A. baumannii. blaoxa-51 was positive in 100%, blandm-i in 95.45%, blaoxa-23 in 77.27%, blavim in 72.73%, blakpc in 50% and blaOXA-58 in 18.18% of imipenem resistant isolates. MDR profile of nosocomial A. baumannii would highlight the importance of standard guideline of antimicrobials use and infection control policy in the hospitals of Bangladesh.

Distribution of New Delhi metallo-beta-lactamase producing Acinetobacter baumannii in patients with ventilator associated respiratory tract infection

Background and objectives: Ventilator-associated respiratory tract infection (VARTI) is a major cause of morbidity and mortality among the critically ill patients of intensive care units (ICU). Acinetobacter baumannii, an important offending pathogen in VARTI, has been found to be resistant to several antibiotics including carbapenems. The present study was conducted to determine the rate of New Delhi metallo-β-lactamase 1(NDM-1) producing A. baumannii causing VARTI among the patients admitted in an ICU of a large tertiary care hospital.Methods: The study was conducted from July 2013 to June 2014. Endotracheal aspirates (ETA) were collected from patients with clinically suspected VARTI. Samples were collected from patients who were on mechanical ventilation for more than 48 hours. ETA samples were cultured aerobically and isolated A. baumannii were tested for susceptibility to carbapenem. Presence of NDM-1 encoded by the blaNDM-1 gene was detected by polymerase chain reaction (PCR).Results: A total of 138 VARTI cases were included in the study. Total 107 (77.5%) bacteria were isolated from 138 ETA samples of which 38 were A. baumannii. Out of 38 isolated A. baumannii, 35 (92.1%) were resistant to imipenem/meropenem and 33 (86.8%) were positive for blaNDM-1 gene by PCR.Conclusion: The present study demonstrated that high proportion of A. baumannii isolated from VARTI cases in ICU were carbapenem resistant and blaNDM-1 positive. Careful infection control program should be considered to contain the spread of this multi-resistant organism to other hospital and community.IMC J Med Sci 2018; 12(1): 37-41

Distribution of adeB and NDM-1 genes in multidrug resistant Acinetobacter baumannii isolated from infected wound of patients admitted in a tertiary care hospital in Bangladesh

BACKGROUND

The adeB gene in Acinetobacter baumannii regulates the bacterial internal drug efflux pump that plays a significant role in drug resistance. The aim of our study was to determine the occurrence of adeB gene in multidrug resistant and New Delhi metallo-beta-lactamase-1 (NDM- 1) gene in imipenem resistant Acinetobacter baumannii isolated from wound swab samples in a tertiary care hospital of Bangladesh.

METHODS

A total of 345 wound swab samples were tested for bacterial pathogens. Acinetobacter baumannii was identified by culture and biochemical tests. Antimicrobial susceptibility pattern was determined by the disc diffusion method according to CLSI standards. Extended spectrum beta-lactamases were screened using the double disc synergy technique. Gene encoding AdeB efflux pump and NDM-1 were detected by Polymerase Chain Reaction (PCR).

RESULTS

A total 22 (6.37%) Acinetobacter baumannii were identified from 345 wound swab samples and 20 (91%) of them were multidrug resistant. High resistance rates to some antibiotics were seen namely, cefotaxime (95%), amoxyclavulanic acid (90%) and ceftriaxone (82%). All the identified Acinetobacter baumannii were sensitive to colistin and 82% to imipenem. Two (9%) ESBL producing Acinetobacter baumannii strains were detected. adeB gene was detected in 16 (80%) out of 20 multidrug resistant Acinetobacter baumannii. 4 (18%) of 22 Acinetobacter baumannii were imipenem resistant. NDM-1 gene was detected in 2 (50%) of the imipenem resistant strains of Acinetobacter baumannii.

CONCLUSION

The results of this study provide insight into the role of adeB gene as a potential regulator of drug resistance in Acinetobacter baumanni in Bangladesh. NDM-1 gene also contributes in developing such resistance for Acinetobacter baumannii.

Detection of Plasmid Mediated AmpC-β lactamases Among Gram-Negative Uropathogens at a Tertiary Care Hospital, Dhaka City

Plasmid-mediated AmpC β-lactamase (PMABL) resistance among gram negative bacilli is an emerging problem worldwide. They likely originate from chromosomal AmpC of certain Gram-negative bacterial species and subsequently are mobilized to transmissible plasmids. There are reports of unfavorable clinical outcomes in patients infected with these organisms and treated with broad-spectrumcephalosporins. The present cross sectional study was designed to detect PMABL genes among gram negative uropathogens in a tertiary care hospital, Dhaka city, Bangladesh from January 2014 to December 2014. Total 138 gram negative uropathogens were identified by the conventional methods and were screened for AmpC production using cefoxitin discs. Confirmatory phenotypic identification was done by modified three dimensional test (MTDT). The common AmpC genotypes ACC, FOX, MOX, DHA, CIT and EBC types were determined by a multiplex PCR.PMABL genes were detected by PCR in 90% of cefoxitin resistant isolates and the molecular types of the genes detected predominantly were CIT, DHA followed by EBC and ACC types. Overall, PMABL genes were detected in 32.61% (45/138) of the studied gram negative uropathogens which is alarming. All (100%) the plasmid mediated AmpC β-lactamase producers showed resistance to amoxicillin-clavulanic acid, ceftazidime, ceftriaxone, cefotaxime and cefoxitin. These results emphasize that clinical laboratories should consider the tests for the detection of PMABL genes for infection control and formulation of effective antibiotic policy.

Emergence of Vancomycin Resistant Staphylococcus aureus during Hospital Admission at a Tertiary Care Hospital in Bangladesh

Background: Glycopeptides such as vancomycin are frequently the choice of antibiotics for the treatment of infections caused by methicillin resistant Staphylococcus aureus (MRSA). For the last 7 years incidence of vancomycin intermediate S. aureus and vancomycin resistant S. aureus (VISA and VRSA respectively) has been increasing in various parts of the world.Objective: The present study was carried out to find out the presence of VISA and VRSA among isolated MRSA strains.Methodology: This cross sectional study was carried out in the Department of Microbiology in Dhaka medical college during period of January 2010 to December 2011. All S. aureus isolates were screened to detect methicillin resistance and then all MRSA isolates were subjected for MIC testing against vancomycin and oxacillin by agar dilution method, disc diffusion testing and PCR for mecA and pvl genes detection.Result: A total 112 S. aureus were isolated from 500 nasal swab sample collected from adult patients who were admitted in various departments and wards in Dhaka Medical College Hospital. Among 38 MRSA strains out of 112 Staph aureus isolates 3(7.89%) strains were resistance to vancomycin of which 2(5.26%) strains had MIC > 256 mg/mL and one strain had MIC 256mg/mL. All vancomycin resistance strains had MIC of oxacillin > 256 mg/mL. All isolates possess mec-A gene.Conclusion: The present study reveals that emergence of VRSA upon admission at a tertiary care of hospital in Bangladesh. Continuous efforts should be made to prevent the spread and the emergence of VRSA by early detection of the resistant strains and using the proper infection control measures in the hospital setting.Bangladesh Journal of Infectious Diseases 2016;3(1):11-16

Prevalence and antibiogram of ESBL producing gram negative bacilli isolated from urine in Dhaka Medical College Hospital, Bangladesh

Extended spectrum ß-lactamase (ESBL) producing strains are resistant to a wide variety of common antimicrobials and become a major clinical concern worldwide that has complicated treatment strategies. The current study has been carried out to detect ESBL producing gram negative bacilli with their antimicrobial susceptibility pattern from urine collected over a period of 12 months from July 2011 to June 2012 from Dhaka Medical College Hospital. Samples were cultured in blood agar and MacConkey's agar media and organisms were identified by different biochemical tests such as oxidase test, reaction in MIU and simmon's citrate media and different sugar fermentation tests. ESBL producers were detected by double-disk synergy test (DDST). From total of 300 urine samples, 157 (52.33%) gram negative bacilli causing UTI were isolated and most of them were Escherichia coli (71.34%) followed by Enterobacter aerogenes (13.38%). Among the isolates, 45 (28.66%) ESBL producers were detected. The highest of ESBL producer was observed in Escherichia coli (32.14%) followed by Klebsiella pneumoniae (28.57%), Enterobacter aerogenes (23.80%) and Acinetobacter spp (20%). ESBL producers were significantly more resistant to ciprofloxacin, gentamycin, doxycycline, amoxiclav and co-trimoxazole than non-ESBL producers. All the ESBL producing strains were sensitive to imipenem. The result of this study provides insight into the high proportion of highly resistant ESBL producing organisms and more effective strategies are needed to control the spread of these resistant organisms.Bangladesh J Med Microbiol 2015; 9 (1): 17-21

Multidrug-resistant, Extensively drug-resistant and Pandrug-resistant bacteria and antimicrobial therapy in combination

Bangladesh J Med Microbiol 2015; 9 (2): 1-2

Antimicrobial Susceptibility Pattern of Extended-spectrum Beta-lactamases Producing Organisms Isolated in a Tertiary Care Hospital, Bangladesh

Context:

Infection caused by extended-spectrum beta-lactamases (ESBL) producing organism is a major problem regarding antibiotic resistance.

Aims:

The aim of this study was to find out the antibiogram of ESBL producing organisms isolated from various samples.

Settings and Design:

This cross-sectional study was carried out in the Department of Microbiology of a Tertiary Care Hospital, Dhaka, Bangladesh from January to June 2014.

Subjects and Methods:

One Hundred and seventy-nine ESBL producing Gram-negative organisms detected phenotypically by double-disc synergy test were enrolled in this study. Required data were collected from the records of the Microbiology laboratory.

Results:

ESBL production was detected in 16.07% (179/1114) of isolated organism. Of Escherichia coli, 15.75% were ESBL producers; 14.01% Pseudomonas spp., 36.84% Proteus spp., 18.57% Klebsiella spp., and 21.05% of Acinetobacter spp., were ESBL producers. Maximum (43.58%) ESBL producers were isolated from surgery departments, and wound swabs yielded majority (53%) of them. About 13% ESBL producers were isolated in outdoor patients mostly from community-acquired infections. Most ESBL producers were resistant to commonly used antibiotics. Carbapenems especially imipenem was the most effective drug showing excellent sensitivity; colistin and piperacillin/tazobactam also had better sensitivity result. Most of the ESBL producers showed a good sensitivity to amikacin, but all of them were highly resistant to ciprofloxacin.

Conclusions:

ESBL production should be detected routinely in all Microbiology laboratories. Infection control, rational use of antibiotics must be done promptly to prevent the development and spread of ESBL producing organisms.

Emergence of CTX-M-15 producing E. coli O25b-ST131 clone in a tertiary care hospital of Bangladesh

BACKGROUND

Extended-spectrum β-lactamase (ESBL) producing uropathogens has become prevalent worldwide. E. coli O25b-ST131 clone, associated with blaCTX-M-15, has been reported from many parts of the world and is frequently associated with multidrug resistance. Thus far, there are no reports about this clone in Bangladesh. The objective of this study was to investigate ESBL producing uropathogens and to survey the prevalence of E. coli O25b-ST131 clone among ESBL positive E. coli isolates.

METHODS

From symptomatic urinary tract infection cases, a total of 800 urine samples were collected. Bacterial identification and antimicrobial susceptibility testing was performed using established methods. Screening of ESBL producers was done using the disk diffusion method. Screening positive isolates were phenotypically confirmed by double disk synergy (DDS) test. Genes encoding ESBLs (blaCTX-M-15, blaOXA-1) were identified both by PCR and DNA sequencing. Phenotypic positive ESBL producers were also studied by PCR for existence of class 1 integron. Subsequently, O25b-ST131 clone was identified by allele specific PCR.

RESULTS

Of 138 gram-negative uropathogens, 45 (32.6%) were positive for ESBLs. ESBL producers showed high frequency of antimicrobial resistance except imipenem. Among 45 ESBL producers, 36 (80%) produced blaCTX-M-15, 18 (40%) produced blaOXA-1. Fifteen (33.3%) strains simultaneously produced both blaOXA-1 and blaCTX-M-15. Class 1 integron was present in 30 (66.7%) isolates. Of the 31 blaCTX-M-15 positive E. coli, 22 (71%) were positive for E. coli O25b-ST131 clone and all (100%) belonged to B2 phylogenetic group.

CONCLUSION

Rising antimicrobial resistance among uropathogens, and especially the emergence of blaCTX-M-15 positive E. coli O25b-ST131 clone in Bangladesh has provided urgency to the development of novel preventive and therapeutic strategies.

Isolation of Extended Spectrum β-Lactamase Producing Gram Negative Bacilli from Wound Swab with Their Antimicrobial Susceptibility Pattern

Extended Spectrum β-lactamases (ESBLs) producing organisms have become the major clinical concern worldwide. The present study was undertaken to see the frequency of ESBLs producing gram-negative bacilli with their antibiogram in post surgical wound swab collected over a period of 12 months from July 2011 to June 2012 at Dhaka Medical College Hospital. Among 200 samples 121(60.5%) gram negative bacilli and 52(26%) gram-positive bacteria were isolated. Escherichia coli (36.42%) was the most predominant gram-negative bacilli followed by Klebsiella species (9.83%) and Pseudomonas aeruginosa (8.67%). Thirty four (28.1%) isolates were detected as ESBLs producers by double-disc synergy test (DDST) and the prevalence among Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were 33.33%, 35.29% and 26.67% respectively. All the ESBL producing strains were sensitive to imipenem but they were significantly more resistant to ciprofloxacin, doxycycline, amoxiclav, co-trimoxazole, azithromycin and gentamycin than non-ESBLs producers (p<0.01). The finding suggests more effective strategies are needed to control the spread of these resistant organisms.

Prevalence of Hepatitis B Virus, Hepatitis C Virus, and HIV in Overseas Job Seekers of Bangladesh with the Possible Routes of Transmission

Hepatitis and AIDS are major public health problem globally. The aim of this study was to determine the sero-prevalence of hepatitis B, C virus and HIV infection among Bangladeshi overseas job seekers. This cross sectional study was carried out in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh from February 2013 to August 2013. A total of 2254 adult (18-45 years) male job seekers to Malaysia attending for health check up were enrolled. HBsAg, Anti-HCV, Anti-HIV were detected from venous blood by ELISA method using commercial kits. From the positive people, further history and information were collected by predesigned questionnaire. Prevalence of HBV was 2.35%, HCV was 0.13% and none was found positive for HIV. Prevalence of hepatitis was higher in the age group of 21-30 year and infection was more prevalent in married group. No significant relationship was found between hepatitis infection and religion, localities, profession. Only a few cases had history of possible major known route of transmission of virus. But most of them had history of taking injection or sharing blades in barber shop and history of circumcision. About 96% population had no history of hepatitis B vaccination. None was co-infected with HBV and HCV. Prevalence of hepatitis B virus infection in adult population appears to be on decline and hepatitis C and HIV infection is still low in Bangladesh. In majority of the positive person, routes of transmission of viruses were not well established.

Prevalence and Antibiogram of Microbial Agents Causing Nosocomial Urinary Tract Infection in Surgical Ward of Dhaka Medical College Hospital

Background: Nosocomial infections pose substantial risk to patients receiving care in hospitals. In Bangladesh, this problem is aggravated by inadequate infection control due to poor hygiene, resource and structural constraints and lack of awareness regarding nosocomial infections.Objective: We carried out this study to determine the prevalence of different microorganisms from urine in surgery ward and antimicrobial susceptibility pattern against various antibiotics.Materials and Methods: This cross sectional study was carried out in Department of Microbiology, Dhaka Medical College, Dhaka over a period of 12 months from July 2011 to June 2012. A total of 52 urine specimens were collected from catheterized patients admitted in general surgery ward of Dhaka Medical College Hospital (DMCH) and incubated in blood agar, MacConkey agar media and the isolates were identified by different biochemical tests – oxidase test and reaction in MIU (motility indole urease) and Simmon’s citrate and TSI (triple sugar iron) media. ESBL producers were detected by double-disk synergy test (DDST).Results: Bacteria were isolated from 35 specimens and Escherichia coli was the commonest isolate (23, 65.71%) followed by Pseudomonas aeruginosa 6 (17.14%), Klebsiella pneumoniae 3 (8.57%), Acinetobacter baumannii 2 (5.72%) and Proteus vulgaris 1 (2.86%) respectively. Among the isolates, 10 (28.57%) ESBL producers were detected and the highest ESBL production was observed in Escherichia coli (8, 22.85%) followed by Klebsiella pneumoniae 1 (2.86%) and Pseudomonas aeruginosa 1 (2.86%). The isolates were resistant to most of the commonly used antimicrobial agents.Conclusion: The emergence of multi-drug resistant (MDR) bacteria poses a difficult task for physicians who have limited therapeutic options. However, the high rate of nosocomial infections and multi-resistant pathogens necessitate urgent comprehensive interventions of infection control.J Enam Med Col 2016; 6(2): 75-79

Detection of potential pathogenic aerobic bacteria from egg shell and egg contents of hen collected from poultry

This study was done to identify different pathogenic aerobic bacteria from egg shell and egg contents of hen. Egg shells and egg contents of 150 eggs collected from poultry were tested. Of 150 egg shells, 130 (86.67%) yielded growth of bacteria and 60 (40%) Esch. coli,.25 (16.67%) Providencia rettgeri, 5 (3.33%) Providencia alkalifaciens, 20 (13.33%) Citrobacter freundii, 10 (6.67%) Salmonella spp, 10 (6.67%) Enterobacter aerogenes were isolated. No bacteria were isolated from 150 egg contents. Total 14 (9.33%) Salmonella spp. from egg shells and 7 (4.67%) Salmonella spp. from egg contents were identified by PCR. Most of the identified serotypes were Salmonella Enteritidis (42.86% from egg shells and 71.43% from egg contents). All (100%) Salmonella Typhi and Salmonella Paratyphi A were sensitive to ciprofloxacin and ceftriaxone.

Diagnosis of common bacterial causes of urethritis in men by Gram stain, culture and multiplex PCR

Urethritis is one of the most important causes of morbidity and mortality in developing countries. The aim of this study was to detect common bacterial causes of urethritis in men by Gram stain, culture and multiplex PCR.185 male patients who presented at the Skin and venereal clinic of the Dhaka Medical College, Bangladesh with clinical symptoms suggestive of urethritis were enrolled in this study. Urethral discharges were tested for detection of Neisseria gonorrhoeae by Gram stain, culture and PCR. Multiplex PCR assay was done to detect DNA of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma genitalium. Out of 185 participants, 30.27% and 14.6% were infected by Neisseria gonorrhoeae and Chlamydia trachomatis respectively. None of the individuals was found positive for either Ureaplasma urealyticum or Mycoplasma genitalium. Among the Neisseria gonorrhoeae positive patients 27.57% were positive from Gram stain, 26.49% were culture positive, 30.27% were positive by PCR (p<0.001). 32.65% of the Neisseria gonorrhoeae isolates were penicillinase producers and 83.67% were susceptible to ceftriaxone. Considering culture as the gold standard, the sensitivity and specificity of PCR for the detection of Neisseria gonorrhoeae was 100%, and 94.85% respectively with an accuracy of 96.22%. 3.73% of the 134 smear negative and 5.15% of the 136 culture negative samples were positive by PCR. PCR was the most sensitive and rapid method for the diagnosis of urethritis. Multiplex PCR may be a useful approach to laboratory diagnosis of urethritis in men for its high sensitivity and specificity.

Community acquired bacterial pneumonia: aetiology, laboratory detection and antibiotic susceptibility pattern

This cross sectional study was conducted to identify the common bacterial causes of community acquired pneumonia (CAP) from sputum and blood by culture and polymerase chain reaction (PCR) and to evaluate the effectiveness of these tests. A total of 105 sputum and blood samples were collected from patients with pneumonia on clinical suspicion. Common causative bacterial agents of pneumonia were detected by Gram staining, cultures, biochemical tests and PCR. Among 55 sputum culture positive cases, a majority (61.82%) of the patients were in the age group between 21-50 years and the ratio between male and female was 2.5:1. Most (61.90%) of the cases were from the lower socio-economic group. Out of 105 samples, 23 (37.12%) were positive by Gram stain, 29 (27.62%) yielded growth in culture media and 37 (35.24%) were positive by PCR for Streptococcus pneumoniae and Haemophilus influenzae. Streptococcus pneumoniae was the most common aetiological agent (19.05%) followed by Klebsiella pneumoniae (13.33%), Haemophilus influenzae (8.57%) and Pseudomonas aeruginosa (5.71%). Multiplex PCR is a useful technique for rapid diagnosis of bacterial causes of pneumonia directly from sputum and blood. Considering culture as a gold standard, the sensitivity of PCR was 96.55% and specificity was 88.15%. More than 80% of Streptococcus pneumoniae isolates were found to be sensitive to ampicillin, amoxycillinclavulanate, and ceftriaxone. Susceptibilities to other antimicrobials ranged from 65% for azithromycin to 70% for levofloxacin. On the other hand, the Gram negative organisms were more sensitive to meropenem, ceftriaxone, amoxycillin-clavulanate and amikacin.

Molecular Detection of Diarrheagenic Escherichia coli from Children with Acute Diarrhea in Tertiary Care Hospitals of Dhaka, Bangladesh

Objective: Multiplex PCR assay was used for diagnosis of diarrheagenic Escherichia coli (DEC) in stool samples of children (under 5 years) with acute diarrhea.  Methods: Samples were collected from January 2011 to December 2011, from Dhaka Medical College Hospital and Dhaka Shishu Hospital. Multiplex PCR with five specific primer pairs to detect enteropathogenic E. coli (eae, bfp), enterotoxigenic E. coli (lt, st) and enteroaggregative E. coli (aat) were used. However, enteroinvasive E. coli, enterohemorrhagicE. coli and diffusely adhererentE. coli were not sought. Result: In total, 135 (67.5%) E. coli were isolated from 200 stool samples. The prevalence of DEC was 68 (34%). Among DEC, most frequently isolated pathotype was EPEC 40 (58.82%), followed by ETEC 24 (35.29%) and EAggEC 18 (26.47%). Among the EPEC, 5 (12.5%) were typical EPEC. Among the 68 DEC positive cases, 22 samples contained more than one pathogenic gene in various combinations. Among the combination of DEC, EPEC+ETEC combination was 6 (27.27%) followed by ETEC+EAggEC 4 (18.18%), EPEC+EAggEC and ETEC+EPEC+EAggEC were both in 3 (13.6%). Conclusion:This study shows that DEC is a common cause of childhood diarrhea in Dhaka city of Bangladesh. By using multiplex PCR assay, DEC can be diagnosed in one PCR reaction that makes a conclusive diagnosis of diarrhea. DOI: http://dx.doi.org/10.3126/ajms.v5i2.8576 Asian Journal of Medical Science, Volume-5(2) 2014: 59-66

Antimicrobial susceptibility pattern of extended spectrum beta-lactamase producing gram-negative bacteria isolated from wound and urine in a tertiary care hospital, Dhaka City, Bangladesh

From a total of 320 bacterial samples from wound swab and urine 169 (53%) gram-negative bacteria were isolated, of which 42 (25%) extended-spectrum beta-lactamase (ESBL) producers were detected by double-disk synergy test. ESBL producers were significantly more resistant against amoxiclav, Co-trimoxazole, ciprofloxacin, amikacin and gentamicin than non-ESBL producers. Among the 42 ESBL producers, 76% were positive for blaCTX-M and 43% were positive for blaOXA, with blaCTX-M predominantly (97%) observed in E. coli and blaOXA predominantly (80%) in Pseudomonas spp. Class 1 integron was found in 75% of blaCTX-M positive and 56% of blaOXA positive strains. Combinations of ESBL genes and class 1 integron were observed in 29 (69%) of the ESBL producers. The findings of this study infer that CTX-M and OXA producers are emerging in Bangladesh and we report the presence of blaOXA for the first time in Bangladesh.

Isolation Of Potential Pathogenic Bacteria From Nasopharynx From Patients Having Cough For More Than Two Weeks

This cross sectional study was done from January 2009 to June 2010 in Microbiology department of Dhaka Medical College on isolation of potential pathogenic bacteria from nasopharynx from patients having cough for more than two weeks. The nasopharyngeal swabs were collected from 290 patients for culture and 101 blood samples were collected for slide agglutination test against anti- Bordetella antibody. In case of culture of nasopharyngeal swabs, 117 (73.12%) samples yielded growth of single organism, 16 (10%) yielded mixed growth and 27 (16.88%) samples yielded no growth in children. In adults, 85 (65.39%) samples yielded growth of single organism, 1 (0.77%) yielded mixed growth and 44 (33.84%) samples yielded no growth. Highest incidence (33.33%) of S. pneumoniae was found in age group of 1-5 years, highest incidence (32.20%) of N. meningitidis was found in age group of 18-25 years and highest incidence (32%) of Staph. aureus was found in age group of 25-50 years. One (0.63%) B. pertussis was isolated from a child and 5 (3.84%) B. parapertussis were isolated from adults. In this study, 116 (83.45%) samples yielded growth in lower socioeconomic group and 101 (70.62%) yielded growth in the samples of middle socioeconomic group. Among the study participants, 31(30.70%) were positive and 70 (69.30%) were negative for antibody against B. pertussis. In anti-Bordetella antibody positive cases, 14 (93.33%) children had duration of cough for 2-3 weeks, 7 (43.75%) adults had duration of cough for 3-4 weeks and 1 (6.25%) adults had more than 6 weeks.DOI: http://dx.doi.org/10.3329/bjmm.v4i2.10826 

Identification of Hookworm Species in Stool By Harada Mori Culture

This cross sectional study was done from January 2009 to June 2010 in Microbiology department of Dhaka Medical College, Dhaka to identify hookworm species and to compare different laboratory methods for diagnosis of hookworm infections. Among the 375 stool samples evaluated, 26 (6.93%) samples were positive for hookworms. Ankylostoma duodenale were 3 (11.50%) and Necator americanus were 23 (88.50%). Harada Mori culture was found as the most effective method for detection of hookworms.DOI: http://dx.doi.org/10.3329/bjmm.v4i2.10821 

Evaluation of bacterial colonization and bacteriuria secondary to internal ureteral stent

To assess the frequency of bacterial colonization on internal ureteral stent and stent associated bacteriuria in different periods of indwelling time, a total of 100 patients (mean age 39.2+/-9.9 years, range 18-60 years, 69 male and 31 female) needing internal ureteral stent placement for different sorts of urinary tract operation in the department of Urology, Dhaka Medical College Hospital from December 2006 to May 2008 were included in the study. Sterile urine samples were obtained from each patient before stenting and all patients had been given short-term prophylactic antibiotics (5-12 days). Midstream urine obtained from each patient on the day of stent removal and submitted for microbiological culture. Stent removed by aseptic precautions. Proximal and distal stent tip segments (3-5) were also sent for culture. The median duration of stenting was 35 days (10-86 days). Bacterial colonies were found in 45% of the stent. Colonization rate was 71.4% in stents removed after 6 weeks compared to 33.3% in 4-6 weeks and 23.5% before 4 weeks (p<0.001). Bacteriuria was found only in 21% patients. Escherichia coli was the common organism isolated from both stent and urine. The study concludes that bacterial colonization significantly increases with indwelling time of stent and absence of growth in urine culture does not rule out that the stent itself is colonized.

Seropositivity of Helicobacter Pylori among the fish handlers

This case control study was done to study the seropositivity of helicobacter pylori among the fish handlers and to find out rapid urease test (RUT) & haematoxillin and eosin staining report correlation of seropositive cases. It was performed among fish handlers in the period of July 2005 to June 2006. Blood samples were collected from fish handlers (Group I) and some non-fish handler control subjects (Group II) to perform Anti-H. Pylori IgG test by ELISA method. Samples were collected from both the sea water area (Paikgacha, Khulna) and fresh water area (Derai, Sunamgonj and Dhaka). Seropositive cases having complaints and treatment history of peptic ulcer diseases were motivated for endoscopic examination to collect biopsy from upper GIT and rapid urease test (RUT) hematoxillin & eosin (H & E) staining were performed. A total of 235 respondents were included in this study, among them 163 were fish handlers (80 sea water and 83 fresh water) and 72 were non fish handler control (25 sea water, 22 fresh water from Sunamgonj, 25 fresh water from Dhaka city). Serum anti- H. pylori test was positive in 126(77.30%) cases in fish handler group (a) and 27(37.5%) cases in the control group (b). Seropositive cases were observed more among the higher age group (>40 years) than in lower age group (<40 years) which was 86% and 67% respectively. Endoscopic examination was done among the seropositive cases having positive PUD features. Total seropositive cases were 153 and among them 81 have positive PUD features, among them 48 cases were selected for endoscopic examination. Among the fish handlers out of 34 cases, 31(91.17%) were RUT positive and out of 14 non-fish handlers 6(42.85%) were RUT positive. Among the fish handlers, 28(82.35%) of the 34-biopsy specimens were H & E positive and among the non-fish handlers, out of 14 samples, 5(35.71%) were H & E positive. Fish handlers have more association of H. Pylori infection than non fish handlers and higher age group persons are more prone to H. Pylori infection. A significant number of seropositive persons have association with positive RUT and H & E staining report.

Risk of nosocomial transmission of Nipah virus in a Bangladesh hospital

We conducted a seroprevalence study and exposure survey of healthcare workers to assess the risk of nosocomial transmission of Nipah virus during an outbreak in Bangladesh in 2004. No evidence of recent Nipah virus infection was detected despite substantial exposures and minimal use of personal protective equipment.

Comparison between ELISA and ICT- MycoDot in adult pulmonary tuberculosis

The present study was conducted to see the diagnostic efficacy of serum anti-TB IgG antibody detection in adult pulmonary tuberculosis (TB) by ELISA and Immunochromatography test (ICT) method using commercially available diagnostic kit (Pathozyme TB complex and MycoDot test respectively). This case-control study included 48 cases of adult pulmonary TB within the age range of 15-65 years. Among them, 22 (45.9%) were AFB positive confirmed cases, 12 (25.0%) were AFB negative clinically diagnosed cases before treatment and 14 (29.1%) were clinically diagnosed cases on treatment. Age and sex matched 33 controls were also included, of which 19 (57.6%) were healthy and 14 (42.4%) were sick with non-specific pulmonary infection. Overall sensitivity and specificity of ELISA were 60.42% & 96.97% (p<0.001) and those of MycoDot as 72.92% & 93.94% (p<0.001). Rate of both ELISA and MycoDot positive were higher among clinically diagnosed cases on treatment with respective values as 71.42% and 85.71%. Respective values among AFB positive confirmed TB cases were 68.18% and 72.72%. As, both ELISA and MycoDot yielded be used as a confirmatory test for TB.

Comparison between ELISA and ICT-MycoDot in childhood tuberculosis

Diagnosis of childhood tuberculosis (TB) is a difficult job. Keeping this fact in mind, the present study was designed to detect serum anti-TB IgG antibody in childhood TB cases by Enzyme Linked Immunosorbent Assay (ELISA) and Immunochromatography test (ICT) method using commercially available diagnostic kit (Pathozyme TB complex and MycoDot test respectively). This case-control study, were done on 52 cases of childhood TB within the age range of 4(+)-14 years. Among them, 15 (28.8%) were AFB positive confirmed cases, 25 (48.1%) were AFB negative clinically diagnosed cases before treatment and 12 (23.1%) were clinically diagnosed cases on treatment. Age and sex matched 36 controls were also included of which 21 (58.3%) were healthy children and 15 (41.7%) were sick children with non-specific pulmonary infection. Overall sensitivity and specificity of ELISA were 34.62% and 97.20% (p<0.001) and those of MycoDot as 48.08% and 96.92% (p<0.001). Rate of both ELISA and MycoDot positive were higher among. clinically diagnosed cases on treatment with respective values as 71.42% and 85.71%. Respective values among AFB positive confirmed TB cases were 40% and 72.72%. Different aspects of immune response in TB were discussed. Since, both method yielded negative results in confirmed TB cases, so none of the methods should be considered as a confirmatory test method for TB.

Direct agglutination test with urine samples for the diagnosis of visceral leishmaniasis

A new direct agglutination test (DAT) for use with urine samples for the diagnosis of visceral leishmaniasis (VL) has been developed and compared with the conventional DAT with serum samples and our previously reported enzyme-linked immunosorbent assay (ELISA) with urine samples (urine ELISA). The new DAT, in which anti-human IgG was used as enhancing antibody, was tested with urine samples from 75 VL patients and 225 non-VL patients and healthy people. The sensitivity of the new DAT (90.7%), was almost the same as that of the conventional DAT (91.0%) and the urine ELISA (93.3%). The specificity of the new DAT (96.4%) was nearly identical with that of the urine ELISA (97.3%). A urine-based DAT has several advantages over the conventional DAT: sample collection is non-invasive and it can process larger numbers of samples with smaller amounts of antigen.

Diagnosis of visceral leishmaniasis by enzyme-linked immunosorbent assay using urine samples

A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.