RESUMEN
Objective: To determine the frequency and antibiogram of pathogens in an Intensive care unit [ICU]
Study Design: Cross-sectional, observational study
Place and Duration of Study: Department of Microbiology, Army Medical College, National University of Science and Technology, Islamabad, from January 2013 to January 2014
Methodology: Clinical samples, received from patients admitted in ICU, were inoculated on various medias like blood agar, chocolate agar, MacConkey agar and urine samples on CLED. These were then incubated at 37°C for 24 hours
Isolates were identified by colony morphology, Gram reaction, catalase test, oxidase test. Species identification in case of Gram Negative Rods was done by using API 20E [BioMerieux]. Antibiotic susceptibility was done by using modified Kirby-Bauer disc diffusion technique. Bacterial isolates were prepared and inoculated on Mueller-Hinton agar plates followed by application of various antibiotic disc [Oxoid, UK] as per manufacturer's instructions. The plates were then incubated at 37°C aerobically for 18 - 24 hours. Zone diameters were measured and interpreted as sensitive and resistant, according to Clinical and Laboratory Standards Institute [CLSI] guidelines
Results: Out of the 367 positive cultures, 116 [31.08%] were Acinetobacter baumannii susceptible to minocycline and tigecycline followed by Klebsiella pneumoniae [n=71, 16%] susceptible to tigecycline and meropenem. Others were Pseudomonas aeruginosa, Escherichia coll, Coagulase Negative Staphylococcus, Staphylococcus aureus, Enterococcus spp., Streptococcus spp., Klebsiella oxytoca, Stenotrophomonas maltophilia, and Candida spp
Conclusion: Acinetobacter baumannii was the most frequently isolated pathogen. Most of the cultures yielding pathogens were from respiratory tract samples. Gram negative isolates were multidrug resistant but most were tigecycline and susceptible to meropenem
RESUMEN
To determine the sensitivity, specificity, Positive Predictive Value [PPV] and Negative Predictive Value [NPV] of Urine Nitrite [NIT] and Leukocyte Esterase [LE] test compared with urine culture for diagnosis of UTI. Validation study. Department of Microbiology, Army Medical College, Rawalpindi, from January 2013 to December 2013. Three hundred fresh uncentrifuged urine samples with suspicion of UTI, were collected and tested for LE and NIT by using [COMBI-10SL, UK] strip. Nitrite was considered as positive if there was a change in color of dipstick from colorless towards pink within 60 seconds. Leukocyte esterase was considered as positive if there was a change in color from off-white towards purple within 2 minutes. Quantitative urine culture was performed by using the strips calibrated to deliver 0.02 ul of urine on Cystine Lactose Electrolyte Deficient [CLED] medium agar. All plates were incubated at 37°C and read after 24 and 48 hours. Culture was considered as gold standard to evaluate the performance of dipstick test. Out of 300 samples, 136 were culture positive and 164 were culture negative. Out of 136 positive culture results, 103 were dipstick positive and 33 were negative. Sensitivity, specificity, positive predictive value and negative predictive value of both nitrite and leukocyte esterase were 75.74%, 68.90%, 66.66% and 77.40% respectively considering culture as gold standard. Dipstick test for the detection of leukocyte esterase and nitrite in urine are sensitive and specific and can be used reliably for the detection of UTI in resource limited setup
RESUMEN
Objective: To assess the in vitro efficacy of doripenem against Pseudomonas aeruginosa and Acinetobacter baumannii using Epsilometer strips
Study Design: Cross-sectional study
Place and Duration of Study: Department of Microbiology, Army Medical College, Rawalpindi and National University of Sciences and Technology, Islamabad, from May 2014 to September 2014
Methodology: A total of 60 isolates of Acinetobacter baumannii and Pseudomonas aeruginosa collected from various clinical samples received from Military Hospital were included in the study. The specimens were inoculated onto blood, MacConkey and chocolate agars. The isolates were identified using Gram staining, motility, catalase test, oxidase test and API 20NE [Biomeriux, France]. Organisms identified as Acinetobacter baumannii and Pseudomonas aeruginosa were included in the study. Bacterial suspensions equivalent to 0.5 McFarland turbidity standard of the isolates were prepared and applied on Mueller Hinton agar. Epsilometer strip was placed in the center of the plate and incubated for 18-24 hours. Minimum Inhibitory Concentration [MIC] was taken to be the point where the epsilon intersected the E-strip. MIC of all the isolates was noted
Results: For Pseudomonas aeruginosa isolates, MIC[50] was 12 [micro]g/mL and MIC[90] was 32 [micro]g/mL. For Acinetobacter baumannii MIC[50] and MIC[90] was 32 [micro]g/mL
Conclusion: Doripenem is no more effective against Pseudomonas aeruginosa and Acinetobacter baumannii in our setting
RESUMEN
Objective: To determine the frequency of carbapenem resistant Acinetobacter in the Military Hospital Rawalpindi, Pakistan
Study Design: Descriptive study
Place and Duration of Study: Department of Microbiology, Army Medical College, from Oct, 2012 to Feb, 2013
Material and Methods: Clinical specimens like naso-bronchial lavage, blood, pus, sputum and catheter tips were inoculated on blood agar and Mac Conkey agar while the urine samples were inoculated on Cystine Lactose Electrolyte Deficient [CLED] agar. Acinetobacter spp. isolated, were later subjected to antimicrobial susceptibility testing using the modified Kirby-Bauer disc diffusion method on Mueller Hinton agar as per Clinical Laboratory and Standards Institute [CLSI] guidelines
Results: Out of a total of 85 Acinetobacter spp. 62 isolates were found to be carbapenem resistant. They were also found to be 100% resistant to ciprofloxacin and ceftriaxone thus becoming multidrug resistant followed by tazobactam piperacillin [98%] and trimethoprim sulphamethoxazole [92%]. Minimum resistance was seen against tigecycline being 21%
Conclusion: It is concluded from our study that there is a high frequency [72.94%] of resistance to carbapenems in Acinetobacter spp. in our setup which is associated with increased morbidity and mortality due to limited treatment options
RESUMEN
Objective: To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc [30microg] and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was = 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were st and ardized equal to 0.5 McFarl and 's turbidity st and ard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc [Oxoid, UK], according to manufacturer's instructions. The plates were then incubated at 37°C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory St and ards Institute [CLSI] guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus [100%] were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 [96%] were sensitive to ceftaroline whereas, 49 [98%] were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Key Words: Ceftaroline. Methicillin resistant Staphylococcus aureus. Linezolid.
RESUMEN
To determine the frequency of isolation of coagulase-negative staphylococci and their resistance to methicillin over a period of time. 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 30microg 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. 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%]. The frequency of isolation of coagulase-negative staphylococci and its methicillin resistance among hospitalised patients is on the rise
Asunto(s)
Humanos , Coagulasa , Resistencia a la Meticilina , Estudios Transversales , Staphylococcus aureus Resistente a MeticilinaRESUMEN
To determine the frequency of Vancomycin Resistant Enterococcus [VRE] in a tertiary care hospital of Rawalpindi, Pakistan. Observational, cross-sectional study. Department of Microbiology, Army Medical College, Rawalpindi, from May 2011 to May 2012. 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. 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. The frequency of VRE was 11.57% with the highest susceptibility to linezolid and chloramphenicol