Usual Presentation Of An Unusual Pathogen - Cryptococcus Laurentii Meningitis: A Case Report

Infections caused by non-neoformans Cryptococcus spp., including Cryptococcus laurentii, previously thought to be saprophyte and non-pathogenic, have become more common during the past few years, particularly in immunocompromised hosts. To the best of our knowledge here, we present the first case of meningitis in an immunocompromised patient due to a fungus that has never been reported in Pakistan. Our patient, a 40-year old male, who had acquired immunodeficiency syndrome (AIDS) was diagnosed as Cryptococcus laurentti meningitis, with a rare neurological manifestation i.e., cryptococcomas and lepto-meningitis. We presume that exposure to pigeon droppings and acquired immunodeficiency syndrome were the risk factors for this case report. He was treated with liposomal Amphotericin (LAMB) and fluconazole but unfortunately, he rapidly deteriorated and ultimately succumbed to the infection. This case underscores the significance of prompt diagnosis and vigorous treatment of Cryptococcus laurentii meningitis, as well as the need for continued surveillance in immunocompromised individuals.

Statistical analysis of strength properties of reactive powder concrete produced from unrefined metekaolin and gear inner wire

Reactive Powder Concrete (RPC) is one of the latest developments in the field of concrete technology and contains about 20% to 25% silica fume and fibre which are not readily available in Nigeria. The research aims at evaluating the effect of incorporating unrefined metakaolin (MK) as substitute of silica fume and gear inner wire (GIW) as fibre on the properties of the RPC using Analysis of Variance (ANOVA). The quantity of the GIW was fixed at 0.25% (by weight of concrete) while that of MK was 10%, 20% and 30% of the cementitious materials. The study considered GIW and MK as factors while compressive, tensile and flexural strengths as responses. The ANOVA of test results depicted that the two factors (unrefined MK & GIW) have significant effect on compressive strength, tensile strength and flexural strengths of the RPC. Moreover, there are substantial influences of interaction of two factors on the selected properties of the RPC. Therefore, unrefined MK and GIW are suitable in the production of RPC.

Assessing Colistin Resistance by Phenotypic and Molecular Methods in Carbapenem-resistant Enterobacterales in a Tertiary Care Hospital in Pakistan

Introduction

Members of Enterobacterales are very common pathogens, which continue to show resistance to many antibiotics. Carbapenem performed well for some time. Colistin was the final hope for the carbapenem-resistant Enterobacterales, but resistance against it has virtually tied the clinician's hands, especially when it comes to treating critically ill patients.

Purpose

Detection of colistin resistance by the agar method as well as by the polymerase chain reaction (mobilized colistin resistance-1 gene) in carbapenem-resistant Enterobacterales.

Materials and Methods

A cross-sectional study from Dec 2019 to Dec 2020 was conducted at the Department of Microbiology, Army Medical College, National University of Medical Sciences Rawalpindi Pakistan. Antimicrobial susceptibility of Enterobacterales was determined according to the Kirby-Bauer disc diffusion method except for colistin. Colistin agar was used, in concentrations of 2 µg/mL and 4 µg/mL. Results were interpreted according to Clinical and Laboratory Standards Institute guidelines 2020. Mobilized colistin-resistant-1 gene in the carbapenem resistant Enterobacterales was detected by performing real-time polymerase chain reaction assay.

Results

Among the 172 carbapenem-resistant Enterobacterales 18 isolates were resistant using the colistin agar test. Whereas by molecular method colistin resistance was detected among 10 isolates that carried mobilized colistin resistance 1 gene, making the frequency of the MCR-1 gene 5.81%. Seventy percent of isolates were from paired blood samples. Eight patients, from whom the colistin resistant gene was isolated expired.

Conclusion

Colistin resistance is a very serious issue and should not be missed in a clinical microbiology laboratory. The phenotypic agar test method is an excellent option for routine use, as it combines ease of performance with affordable cost. However, molecular methods are essential for the detection of mobilized colistin resistance gene (1-9) for epidemiological purposes.

Molecular Detection of Chlamydia Trachomatis in Patients with Pelvic Inflammatory Disease Visiting a Tertiary Care Hospital in Pakistan

Objective: To detect the frequency of Chlamydia trachomatis in urine samples of women with Pelvic Inflammatory Disease visiting a tertiary care hospital using a Polymerase Chain Reaction assay and find an association between different risk factors. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Army Medical College/National University of Medical Sciences Rawalpindi Pakistan, from Mar 2018 to Jan 2019. Methodology: Over eleven months, 60 diagnosed urine samples of married females with pelvic inflammatory disease between the ages of 14-49 years were included in the study. DNA of Chlamydia trachomatis from urine samples was extracted manually using the commercially available kit. It was detected by performing a real-time Polymerase Chain Reaction assay using a forward primer (5’-CATGAAAACTCGTTCCGAAATAGAA-3’) and a reverse primer (5’-TCAGAGCTTTACCTAACAACGCATA-3’) of sequence mentioned above for amplification of target sequences, of the Chlamydia trachomatis. Results: Out of sixty cases included in this study, Chlamydia trachomatis DNA was detected in 12 cases (20%), and 48 cases (80%) were negative. So, the frequency of Chlamydia trachomatis in our study population was estimated at 20%. In addition, age, socioeconomic status, education and no of sexual partners were all risk factors were evaluated for their role in acquiring infection. Conclusion: Females having Chlamydia trachomatis infection and other sexually transmitted infections are at an increased risk of developing Pelvic Inflammatory disease due to the presence of risk factors and the asymptomatic nature of the disease.

Thrombocytopenia in Pregnancy: A Cross-Sectional Study in Northern Pakistan

Objective: To determine the association of thrombocytopenia (mild, moderate & severe) with pregnancy-related disorders. Study Design: Cross-sectional study. Place and Duration of Study: Department of Haematology of Pakistan Railway Hospital, Rawalpindi Pakistan, in collaboration with the Departments of Obstetrics and Gynecology of Pak Emirates Military Hospital and Fuji Foundation Hospital, Rawalpindi Pakistan, from Oct 2018 to Oct 2019. Methodology: Seventy-five pregnant females with platelet count <150x109/l were included. Blood samples were taken and analyzed for complete blood count, peripheral blood smear, manual count by Neubauer chamber, uric acid, urinary proteins, liver function tests (bilirubin & aspartate aminotransferase), lactate dehydrogenase, coagulation profile and viral serology (Hepatitis B & C). Results: Out of a total of 75 thrombocytopenic pregnant females, gestational thrombocytopenia was most common (74.7%), followed by preeclampsia (17.3%), HELLP syndrome (4%), immune thrombocytopenic purpura (4%) respectively. Mild thrombocytopenia was frequently observed in patients of G.T. (62.5%), while moderate thrombocytopenia (84.6%) was generally detected in preeclampsia patients. Severe thrombocytopenia was mostly identified in patients with HELLP syndrome (66.7%) and immune thrombocytopenic purpura (66.7%). Conclusion: Mild thrombocytopenia is mostly presented in gestational thrombocytopenia. Moderate thrombocytopenia was frequent in patients with preeclampsia, and severe thrombocytopenia was usually diagnosed in patients with HELLP syndrome and immune thrombocytopenic purpura, which require apposite and judicious management for the safety of mother and fetus.

MDR BACTERIAL INFECTIONS IN CRITICALLY ILL COVID-19 PATIENTS IN A TERTIARY CARE HOSPITAL (OF PAKISTAN)

Objective: To identify antimicrobial susceptibility pattern of multidrug resistant bacteria causing secondary infections in COVID-19 patients in ICU’ sofa tertiary care hospital. Study Design: Cross–sectional study. Place and Duration of Study: Department of Microbiology, Pak Emirates Military Hospital, Rawalpindi, from Apr to Jul 2020. Methodology: This study included blood samples and endotracheal aspirates from 114 critically ill COVID-19 patients. Peripheral blood specimens were collected fromthe patients with secondary bacterial blood stream infections and endotracheal aspirates were collected from patients with ventilator associated pneumonia for culture and sensitivity. The results were interpreted according to Clinical & Laboratory Standard Institute (CLSI) 2020. Results: A total of 114 COVID-19 patients were admitted in ICU during that time period. Fourteen (12.28%) were female and 100 (87.71%) were male, age distribution was between 36-82 years. Sixty six paired blood samples were sent to the microbiology lab out of which 51 (77.2%) showed bacterial growth while 15 (22.7%) samples were negative. Out of 50 endotracheal aspirates, 42 showed bacterial growth (84%) and 8 samples did not show any significant bacterial growth (16%). Most of the endotracheal aspirates showed growth of >1 bacterial isolates. The most common gram-negative organisms were Acinetobacter baumannii (n=54) and Klebsiella pneumonia (n=26) and most common gram-positive organism isolated was Enterococcus faecium (n=9). All isolated organisms were multidrug resistant. Conclusion: Poor antimicrobial stewardship particularly in critical care units resulted in secondary bacterial infections in COVID-19 patients. The pathogens isolated were multidrug resistant including Acinetobacter baumannii, Klebsiella pneumonia and Enterococcus faecium.

MULTIPLEX POLYMERASE CHAIN REACTION (PCR) FOR THE DETECTION OF NEISSERIA GONORRHOEAE AND THE QUINOLONE RESISTANCE GENE IN PAKISTAN

Objective: To detect Neisseria gonorrhoeae from the urine of male patients reporting with active urethral discharge using multiplex polymerase chain reaction (PCR). And the simultaneous detection of the quinolone resistance determining region (QRDR) on the Neisseria gonorrhoeae gene using multiplex polymerase chain reaction. Study Design: Cross sectional study. Place and Duration of Study: Microbiology department, Army Medical College Rawalpindi Pakistan, from Mar to Dec 2018. Methodology: Male patients with active urethral discharge with no past history of antibiotic use for urethral discharge were included in study and patients without active urethral discharge and history of antibiotic use for urethral discharge were excluded. Urine of patients of active urethral discharge was collected and multiplex polymerase chain reaction was done by using two forward primers along with common reverse primer. Results: In this study 24 (40%) of patients who presented with active urethral discharge were positive for gonorrhea. However Quinolone Resistance Determining Region is detected in 17 (70.83%) of cases and only 7 (29.17%) were sensitive to ciprofloxacin. Conclusion: The multiplex polymerase chain reaction is very efficient and effective method for the simultaneous detection of Neisseria gonorrhoeae and status of isolate susceptibility to ciprofloxacin. And in Pakistan ciprofloxacin cannot be used as first line drug for the treatment of gonorrhea.

Genetic Diversity of Human Immunodeficiency Virus Type 1 in Asymptomatic Blood Donors in Islamabad, Pakistan

Objective  The serological testing of human immunodeficiency virus (HIV) is mandatory under the blood safety legislation of Pakistan; hence, data exist on the prevalence of HIV in blood donors. However, little is known about the molecular epidemiology of HIV in the blood donor population. Therefore, the current study was designed to study the genetic diversity of HIV-1 infection in a population of apparently healthy treatment-naive blood donors in Islamabad, Pakistan.

Material and Methods  A total of 85,736 blood donors were tested for HIV by the chemiluminescence immunoassay. All positive donor samples were analyzed for the presence of various HIV genotypes (types and subtypes). Viral ribonucleic acid was extracted from blood samples of HIV positive donors and reverse transcribed into complementary deoxyribonucleic acid (cDNA). The cDNA of all positive donors was then analyzed for the presence of various HIV genotypes (types and subtypes) by employing subtype-specific primers in a nested polymerase chain reaction. The amplified products were run on ethidium bromide-stained 2% agarose gel and visualized using a ultraviolet transilluminator. A particular subtype was assigned to a sample if the subtype-specific reaction made a band 20% highly intense compared with the band made by the subtype-independent reaction.

Results  A total of 85,736 blood donors were screened for the presence of antibodies to HIV. Out of them, 114 were initially found reactive for HIV. The repeat testing resulted in 112 (0.13%) positive donors, 95% confidence interval 0.0014 (0.0011–0.0018). These 112 samples were analyzed for molecular typing of HIV-1. The predominant HIV-1 subtype was A ( n = 101) (90.1%) followed by subtype B ( n = 11) (9.9%).

Conclusion  These findings are key to understand the diversified HIV epidemic at the molecular level and should assist public health workers in implementing measures to lessen the further dissemination of these viruses in the country.

Evaluation of screening effectiveness of hepatitis B surface antigen and anti-HCV rapid test kits in Pakistan

OBJECTIVE

The current study was conducted to evaluate the performance and screening effectiveness of commercially available rapid screening kits in comparison with chemiluminescence immunoassay (CLIA) and polymerase chain reaction (PCR).

MATERIALS AND METHODS

This single-center, cross-sectional study was conducted at the Department of Pathology and Blood Transfusion Services, Shaheed Zulfiqar Ali Bhutto Medical University, PIMS, Islamabad, from January to April 2019. A total of 10 commercially available immunochromatographic test (ICT) devices and one CLIA kit (LIAISON XL) were tested for their sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy using 100 positive and 100 negative samples each for HBV and HCV, respectively.

RESULTS

The sensitivities and specificities of ICT kits for hepatitis B surface antigen were 65% and 70% (Hightop), 67% and 85% (RightSign), 62% and 73% (Wondfo), 70% and 80% (Accu-Chek), 68% and 77% (Fastep), 73% and 85% (Abon), 77% and 83% (ImmuMed), 80% and 90% (Insta-Answer), 67% and 81% (BioCheck), and 72% and 83% CTK Biotech, respectively. Similarly, the sensitivities and specificities of different ICT kits for HCV were 69% and 80% (Hightop), 76% and 83% (RightSign), 69% and 81% (Wondfo), 78% and 79% (Accu-Check), 68% and 68% (Fastep), 63% and 73% (Abon), 71% and 70% (ImmuMed), 79% and 68% (Insta-Answer), 62% and 66% (BioChek), and 69% and 78% CTK Biotech, respectively. The sensitivity and specificity of Diasorin Liaison Murex assay for both HBV and HCV were found to be 100% when compared with PCR. The PPV, NPV and Accuracy were determined accordingly.

CONCLUSION

Rapid testing ICT devices for both HBV and HCV available in Pakistan were found to have a variable degree of sensitivity and specificity when compared with CLIA and PCR. Comparatively expensive but quality methods are more reliable as compared to rapid devices.

Methicillin resistant coagulase negative staphylococcus: From colonizer to a pathogen

The objective of our study was to determine the frequency of methicillin resistance in coagulase negative Staphylococcus (CoNS) and to determine its in-vitro antimicrobial susceptibility to various other routinely used antibiotics. It was a cross sectional study conducted at the department of Microbiology, Army Medical College, Rawalpindi, Pakistan from June 2011 to May 2012. The organisms were identified on the basis of colony morphology, Gram staining, catalase, DNAase and slide/tube coagulase tests. The organisms were considered to be methicillin resistant when the diameter of zone of inhibition was less than 25mm around 30μg cefoxitin disc. Antibiotic sensitivity was determined using the Modified Kirby-Bauer disc diffusion method. From a total of 337 CoNS, 201 were methicillin resistant and were included in the study. All were resistant to Penicillin, followed by Erythromycin (93•1%), Ciprofloxacin (77%), Co-trimoxazole (74•8%), Gentamicin (68•3%), Clindamycin (51•06%), Tetracycline (44•6%), Fusidic acid (40%), Rifampicin (39•5%), Chloramphenicol (19•3%), Linezolid (2%), Minocycline (1•1%), and Vancomycin (0%). More than half of CoNS were methicillin resistant. Vancomycin is the only drug to which all of the MRCoNS were sensitive, with more than 98% of the isolates being sensitive to Linezolid and Minocycline.

IN VITRO SUSCEPTIBILITY PATTERN OF EXTENDED SPECTRUM β-LACTAMASE PRODUCING GRAM NEGATIVE BACILLI AGAINST TETRACYCLINES

BACKGROUND

Extended Spectrum β-lactamases (ESBLs) are emerging as common nosocomial pathogens and important cause of mortality and morbidity, if not treated properly. The need of the hour is to find effective treatment options for dealing with ESBL producing organisms. This study was aimed to evaluate in vitro susceptibility pattern of extended spectrum β-lactamase producers against tetracyclines.

METHODS

This descriptive cross-sectional study was carried out in the department of Microbiology, Army Medical College, Rawalpindi, National University of Sciences and Technology over a period of 6 months. Seventy eight non-duplicate isolates were included in the study. ESBL detection was done using Jarlier et al method. In vitro susceptibility of tetracyclines like tetracycline, doxycycline, minocycline and tigecycline was then tested using Modified Kirby Bauer disc diffusion method. The zones of inhibition were measured after completion of incubation period and interpreted as per CLSI and FDA guidelines.

RESULTS

Approximately 56.4% of the isolates were Escherichia coli, 28.2% were Klebsiella pneumoniae, 10.26% were Enterobacter species, and 2.6% were each Klebsiella oxytoca and Acinetobacter species. ESBLs were found to be most sensitive to tigecycline, intermediate in susceptibility to minocycline while least sensitive to doxycycline and tetracycline.

CONCLUSION

Among tetracyclines, tigecycline has best in vitro susceptibility against ESBL producing Gram negative rods.

In vitro Efficacy of Meropenem, Colistin and Tigecycline Against the Extended Spectrum Beta-Lactamase Producing Gram Negative Bacilli

OBJECTIVE

To compare the in vitro efficacy of meropenem, colistin and tigecycline against extended spectrum Betalactamase producing Gram negative bacilli by minimal inhibitory concentration.

STUDY DESIGN

Cross-sectional descriptive study.

PLACE AND DURATION OF STUDY

Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, from June to December 2010.

METHODOLOGY

Routine clinical specimens were subjected to standard microbiological procedures and the isolates were identified to species level. Extended spectrum β-lactamase producing Gram negative bacilli were detected by Jarlier disc synergy method and confirmed by ceftazidime and ceftazidime-clavulanate Etest. Minimum Inhibitory Concentration (MIC(90)) of meropenem, colistin and tigecycline was determined by Etest (AB BIOMERIUX) and the results were interpreted according to the manufacturer's instructions and Clinical and Laboratory Standards Institute guidelines and Food and Drug Authority recommendations. Results were analyzed by using Statistical Package for the Social Sciences version 20.

RESULTS

A total of 52 non-duplicate extended spectrum Beta-lactamase-producing Gram negative bacilli were included in the study. The MIC(90) of tigecycline (0.75 µg/ml) was lowest as compared to the meropenem (2 µg/ml) and colistin (3 µg/ml).

CONCLUSION

Tigecycline is superior in efficacy against the extended spectrum Beta-lactamase producing Gram negative bacilli as compared to colistin and meropenem.

Coagulase negative staphylococci - a fast emerging threat

OBJECTIVE

To determine the frequency of isolation of coagulase-negative staphylococci and their resistance to methicillin over a period of time.

METHODS

The descriptive cross-sectional study was carried out at Army Medical College, Rawalpindi, from June 2009 to May 2012, and comprised clinical samples mostly from patients admitted to the intensive care unit. They were inoculated onto appropriate culture media depending upon the specimen. After 24-hour incubation at 35°C, coagulase-negative staphylococci were identified on the basis of colony morphology, gram staining, a positive catalase and a negative tube coagulase test.Methicillin resistance among the isolated staphylococci was determined using a 30µg Cefoxitin disc as per the Clinical and Laboratory Standards Institute protocol. Number of coagulase-negative staphylococci for each year and their methicillin resistance rates were calculated. A comparison was made with methicillin resistant staphylococcus aureus) isolated during the same period.

RESULTS

Of the total 1331 specimens studies over three years, 581(43.65%) were coagulase-negative staphylococci. The rate of coagulase-negative staphylococci and methicillin resistance was higher each year; 110(26.6%) in May 2009-Jun 2010, 134(36.5%) in 2011, and 337(61%) in 2012. Methicillin resistance rates also increased from 25(22.7%) to 46(34.3%) and then to 201(59.6%) in 2012.Maximum isolated specimens came from blood 311(53.5%), followed by pus/swabs 204(35.1%).

CONCLUSIONS

The frequency of isolation of coagulase-negative staphylococci and its methicillin resistance among hospitalised patients is on the rise.

Incidence and susceptibility pattern of methicillin resistant coagulase-negative staphylococci isolated from a tertiary care hospital of pakistan

BACKGROUND

Methicillin resistant coagulase-negative Staphylococci are resistant organisms causing infections associated with high morbidity and mortality. Methicillin resistant Staphylococcus epidermidis (MRSE), is especially important with respect to admitted patients with indwelling catheters and other installed invasive devices where these organisms are known to be found. As a result, such lifesaving measures may prove fatal from subsequent infection and sepsis by these pathogens. Therefore, to limit such conditions in patients, the spread of MRSE and related organisms in the hospitals have to be effectively controlled.

OBJECTIVES

This study was carried out to determine the frequency of methicillin resistant organisms among all isolated coagulase negative Staphylococci (CoNS) and to find effective antibiotics against these microorganisms.

PATIENTS AND METHODS

All samples sent to the lab were routinely processed according to standard microbiological procedures and the cultures yielding growth of CoNS were selected for the study. All samples containing CoNS collected over a 2 year-period, were included irrespective of patients' age and gender. The antibiogram of the organisms was recorded according to CLSI guidelines and the ratio of methicillin resistant organisms determined.

RESULTS

From a total of 299 isolated coagulase negative Staphylococci (CoNS), 40.1% were methicillin resistant. A high proportion of these organisms (more than 50%) were resistant to cephalosporins, aminoglycosides and quinolones while only a small number were found to show resistance to linezolid, minocycline, chloramphenicol and rifampicin. There were no resistant organisms against vancomycin.

CONCLUSIONS

A considerable amount of methicillin resistant organisms found among CoNS in our region. The above stated antibiotics would prove effective in limiting these infections. Clinicians should keep these facts in mind while treating their patients.

Frequency and antibiogram of vancomycin resistant enterococcus in a tertiary care hospital

OBJECTIVE

To determine the frequency of Vancomycin Resistant Enterococcus (VRE) in a tertiary care hospital of Rawalpindi, Pakistan.

STUDY DESIGN

Observational, cross-sectional study.

PLACE AND DURATION OF STUDY

Department of Microbiology, Army Medical College, Rawalpindi, from May 2011 to May 2012.

METHODOLOGY

Vancomycin resistant Enterococcus isolated from the clinical specimens including blood, pus, double lumen tip, ascitic fluid, tracheal aspirate, non-directed bronchial lavage (NBL), cerebrospinal fluid (CSF), high vaginal swab (HVS) and catheter tips were cultured on blood agar and MacConkey agar, while the urine samples were grown on cystine lactose electrolyte deficient agar. Later the antimicrobial susceptibility testing of the isolates was carried out using the modified Kirby-Bauer disc diffusion method on Mueller Hinton agar.

RESULTS

A total of 190 enterococci were isolated. Of these, 22 (11.57%) were found to be resistant to vancomycin. The antimicrobial sensitivity pattern revealed maximum resistance against ampicillin (86.36%) followed by erythromycin (81.81%) and gentamicin (68.18%) while all the isolates were 100% susceptible to chloramphenicol and linezolid.

CONCLUSION

The frequency of VRE was 11.57% with the highest susceptibility to linezolid and chloramphenicol.

Correlation of 13C urea breath test values with Helicobacter pylori load among positive patients

BACKGROUND/AIMS

13C urea breath test (13C UBT) is used to detect Helicbacter (H.) pylori in gastric mucosa. There are controversial results regarding associations of 13C UBT values with histopathological grades. We designed this study to correlate 13C UBT values with different histopathological grades in our local setting.

METHODOLOGY

13CO2/12CO2 ratio for 13C UBT was analyzed using mass spectrometry and histopatholgical grades were scored by updated Sydney System.

RESULTS

13C UBT values of H. pylori positive patients at different times (T10-T60) were higher as compared to negative patients. Significant positive correlation of 13C UBT values at T30 with different scores of H. pylori load (r = 0.277, p = 0.037) was observed. Associations of the mean 13C UBT values with neutrophil infiltration (p = 0.214), mononuclear cell infiltration (p = 0.648), atrophy (p= 0.620), atypia (p = 0.057) and metaplasia scores (p = 0.718) were found to be nonsignificant. H. pylori load significantly correlated with neutrophil infiltration and atrophy with exception of mononuclear cell infiltration, atypia and metaplasia.

CONCLUSIONS

In the present analysis, significant positive correlation was observed between 13C UBT values and H. pylori load that would be helpful in qauntification of H. pylori in our local setting.

Evaluation of different phenotypic methods for detection of amp C Beta-lactamase producing bacteria in clinical isolates

OBJECTIVE

To compare the sensitivity and specificity of different phenotypic methods for detection of Amp C betalactamase producing bacteria.

STUDY DESIGN

Analytical study.

PLACE AND DURATION OF STUDY

Department of Microbiology, Army Medical College / National University of Sciences and Technology (NUST), Islamabad, Pakistan, from June 2010 to December 2010.

METHODOLOGY

A total of 150 clinical isolates were screened for presence of Amp C beta-lactamase by using the cefoxitin disc. The confirmatory methods evaluated were inhibitor based assay (boronic acid), Amp C disc test and Amp C Etest. Three dimensional enzyme extract assay was used as the reference method for determining the sensitivity and specificity.

RESULTS

Among the total isolates tested, 62.8% bacteria showed the presence of Amp C beta-lactamase by standard three dimensional enzyme extract assay. Among the three methods compared, boronic acid disk test found out to be highly sensitive (88%) and specific (92%) for the detection of Amp C beta-lactamase producing bacteria.

CONCLUSION

Detection of Amp C production is crucial in order to establish the antibiotic therapy and to attain the favourable clinical outcomes. Implementation of simple tests like boronic acid disk tests in the laboratories will help to alleviate the spread of Amp C beta-lactamase harboring organisms.

Frequency and antibiogram of multi-drug resistant Pseudomonas aeruginosa

OBJECTIVE

To find out the frequency and susceptibility pattern of multi-drug resistant (MDR) Pseudomonas aeruginosa in clinical specimens.

STUDY DESIGN

Cross-sectional observational study.

PLACE AND DURATION OF STUDY

Department of Microbiology, Army Medical College, National University of Sciences and Technology (NUST), Rawalpindi, from January to September 2010.

METHODOLOGY

Routine clinical specimens were subjected to standard microbiological procedures and the isolates were identified to the species level. The antibiotics susceptibility was determined by Kirby Bauer Disc diffusion method and the results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

RESULTS

The frequency of MDR Pseudomonas aeruginosa among all the Pseudomonas aeruginosa strains isolated was found to be 22.7%. These isolates were most sensitive to Colistin followed by Piperacillin-Tazobactam and Cefoperazone-Sulbactum.

CONCLUSION

Increasing fequency of infections due to MDR Pseudomonas aeruginosa is an emerging threat in our set up which an be prevented by prescribing antibiotics judiciously and by adopting proper disinfection measures.

Evaluation of different detection methods of biofilm formation in the clinical isolates

BACKGROUND

Microorganisms growing in a biofilm are associated with chronic and recurrent human infections and are highly resistant to antimicrobial agents. There are various methods to detect biofilm production like Tissue Culture Plate (TCP), Tube method (TM), Congo Red Agar method (CRA), bioluminescent assay, piezoelectric sensors, and fluorescent microscopic examination.

OBJECTIVE

This study was conducted to compare three methods for the detection of biofilms.

METHOD

The study was carried out at the Department of Microbiology, Army Medical College, National University of Sciences and Technology, Pakistan, from January 2010 to June 2010. A total of 110 clinical isolates were subjected to biofilm detection methods. Isolates were identified by standard microbiological procedures. Biofilm detection was tested by TCP, TM and CRA. Antibiotic susceptibility test of biofilm producing bacteria was performed by using the Kirby-Bauer disc diffusion technique according to CLSI guidelines.

RESULTS

The TCP method was considered to be superior to TM and CRA. From the total of 110 clinical isolates, TCP method detected 22.7% as high, 41% moderate and 36.3% as weak or non-biofilm producers. We have observed higher antibiotic resistance in biofilm producing bacteria than non-biofilm producers.

CONCLUSION

We can conclude from our study that the TCP method is a more quantitative and reliable method for the detection of biofilm forming microorganisms as compared to TM and CRA methods, and it can be recommended as a general screening method for detection of biofilm producing bacteria in laboratories.

Evaluation of the current trend of nalidixic acid susceptibility in typhoidal Salmonellae; a marker of therapeutic failure for the fluoroquinolones

BACKGROUND AND OBJECTIVES

Typhoid is a major health problem faced by the developing countries like Pakistan. More than 20 million cases are reported annually worldwide. Currently fluoroquinolones are the drugs of choice to treat typhoid fever. In vivo resistance to fluoroquinolones leading to therapeutic failure is developing rapidly and is becoming a major concern for the clinicians. The objective of this study was to determine the sensitivity pattern of Nalidixic acid over the last four years

MATERIAL AND METHODS

A descriptive cross sectional study was carried out at the Microbiology Department of the Army Medical College, National University of Sciences and Technology, Rawalpindi from January 2006 to December 2009. All the isolates were dealt with standard microbiological procedures. The antimicrobial sensitivity of Nalidixic acid and Ciprofloxacin was determined using Kirby-Bauer disc diffusion method as per the guidelines of Clinical and Laboratory Standard Institute (CLSI).

RESULTS

Out of 240 isolates, 111 were Salmonella typhi and 129 were Salmonella paratyphi A. The resistance of the typhoidal Salmonella to Nalidixic acid has reached significant levels and it seems only a matter of time when hundred percent resistance will be encountered. All isolates were sensitive to Ciprofloxacin on disc diffusion method.

CONCLUSION

Resistance to Nalidixic acid predicting therapeutic failure with fluoroquinolones is on a steady rise.

Comparison of in vitro efficacy of linezolid and vancomycin by determining their minimum inhibitory concentrations against methicillin resistant Staphylococcus aureus (MRSA)

OBJECTIVES

To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus.

METHODS

The study was conducted over a period of 6 months (1st July 2009-31st Dec 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips.

RESULTS

All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs.

CONCLUSION

This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections.

Frequency and susceptibility pattern of metallo-beta-lactamase producers in a hospital in Pakistan

INTRODUCTION

The rapid spread of acquired metallo-beta-lactamases (MBLs) among major Gram-negative pathogens is an emerging threat and a matter of particular concern worldwide.

METHODOLOGY

This descriptive study was conducted between January and August 2009 in the department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, to determine the frequency and susceptibility patterns of MBL-producers among carbapenem-resistant Gram-negative rods (GNRs) from clinical isolates of a tertiary care hospital. All clinical samples were processed according to standard microbiological methods. Isolated GNRs were subjected to susceptibility testing against various antibiotics by disc diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.  Carbapenem-resistant isolates were subjected to the detection of MBL production by the E-test MBL strip method.

RESULTS

Out of 50 carbapenem resistant isolates, 39 (78%) of were confirmed to be MBL producers by the E-strip method.  Acinetobacter baumannii were the most frequent MBL producers, followed by Pseudomonas aeruginosa. A total of 19 (37%) of the MBL producers were susceptible to cefoperazone-sulbactam.

CONCLUSION

The findings strongly suggest that there is a need to track the detection of MBL producers and that judicious use of carbapenems is necessary to prevent the further spread of these organisms.

Extended-spectrum ß-lactamase production in Shigella flexneri

Emergence of multidrug-resistant strains of Shigella is a growing concern across the globe. Third-generation cephalosporins are used for treating infections caused by multidrug-resistant Shigellae. However, resistance to these cephalosporin antibiotics due to extended-spectrum ß-lactamases, has emerged as a new problem. So far extended-spectrum ß-lactamases producing Shigella has not been reported from Pakistan. We report such a case in Shigella flexneri from an 8-year old girl with acute dysentery.

Sensitivity pattern of methicillin resistant Staphylococcus aureus isolated from patients admitted in a tertiary care hospital of Pakistan

BACKGROUND AND OBJECTIVES

Methicillin resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen causing significant morbidity and mortality. The aim of this study was to evaluate in vitro activities of different antibiotics against methicillin resistant Staphylococcus aureus.

MATERIALS AND METHOD

The study was conducted over a period of one year (January 2009 - December 2009) in the Department of Microbiology, Army Medical College, the National University of Sciences and Technology, Pakistan. One hundred and thirty-nine Methicillin resistant Staphylococcus aureus isolated from the clinical specimens at Rawalpindi Military Hospital were subjected to in vitro susceptibility against various antimicrobials using Kirby Bauer disc diffusion technique.

RESULTS

All the isolated MRSA organisms were uniformly susceptible to vancomycin, linezolid and tigecycline. Other drugs which were found to be effective were chloramphenicol, and rifampacin. Most of the MRSA were isolated from pus samples.

CONCLUSION

Vancomycin, tigecycline and linezolid were effective against methicillin resistant strains of S.aureus. This study suggests that chloramphenicol and rifampacin also have good in vitro efficacy for methicillin resistant S. aureus infections. Oral dosing option for linezolid, chloramphenicol and rifampacin can allow earlier discharge of hospitalized patients and thus reduce health care expenses as well as help reduce the chances of vancomycin resistant strains emergence.

Frequency of food items among households in a low socioeconomic area of Karachi

OBJECTIVE

To describe the frequency of certain food items among families in a low socioeconomic area of Karachi and their association with socioeconomic variables.

METHOD

A cross sectional survey of houses selected through random sampling using a pre-tested structured questionnaire.

RESULTS

A total of 294 houses were surveyed, 23% households consumed meat almost daily, 55% consumed vegetables almost daily.

CONCLUSION

The survey showed that the consumption of food items in our study population is less as compared to what is recommended.