Molly Johny

Antibacterial resistance and their genetic location in MRSA isolated in Kuwait hospitals, 1994-2004

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of serious infections in hospitals and in the community worldwide. In this study, MRSA isolated from patients in Kuwait hospitals were analyzed for resistance trends and the genetic location of their resistance determinants.MethodsBetween April 1994 and December 2004, 5644 MRSA isolates obtained from different clinical samples were studied for resistance to antibacterial agents according to guidelines from the National Committee for Clinical Laboratory Standards and the British Society for Antimicrobial Chemotherapy. The genetic location of their resistance determinants was determined by curing and transfer experiments.ResultsThey were resistant to aminoglycosides, erythromycin, tetracycline, trimethoprim, fusidic acid, ciprofloxacin, chloramphenicol, rifampicin, mupirocin, cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide but susceptible to vancomycin, teicoplanin and linezolid. The proportion of the isolates resistant to erythromycin, ciprofloxacin and fusidic acid increased during the study period. In contrast, the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined. High-level mupirocin resistance increased rapidly from 1996 to 1999 and then declined. They contained plasmids of 1.9, 2.8, 3.0, 4.4, 27 and 38 kilobases. Genetic studies revealed that they carried plasmid-borne resistance to high-level mupirocin resistance (38 kb), chloramphenicol (2.8 – 4.4 kb), erythromycin (2.8–3.0 kb) and cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide (27 kb) and chromosomal location for methicillin, the aminoglycosides, tetracycline, fusidic acid, ciprofloxacin and trimethoprim resistance. Thus, the 27 kb plasmids had resistance phenotypes similar to plasmids reported in MRSA isolates in South East Asia.ConclusionThe prevalence of resistance to erythromycin, ciprofloxacin, high-level mupirocin and fusidic acid increased whereas the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined during the study period. They contained 27-kb plasmids encoding resistance to cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide similar to plasmids isolated in MRSA from South East Asia. Molecular typing of these isolates will clarify their relationship to MRSA from South East Asia.

Surveillance of antibacterial resistance in Staphylococcus aureus isolated in Kuwaiti hospitals.

Objective: To investigate the prevalence of antibiotic resistance among Staphylococcus aureus isolated in Kuwaiti hospitals. Materials and Methods:S. aureus were isolated and identified following standard microbiological methods. Antibacterial susceptibility test was performed by disk diffusion and the measurement of minimum inhibitory concentration with E-test strips. Results: A total of 1,846 S. aureus isolates were analyzed from 13 hospitals between 1 March and 30 October 2005. They were isolated from 1,765 (95.6%) inpatients and 81 (4.4%) outpatients. Methicillin resistance was detected in 588 (32.0%) of the isolates. The methicillin-resistant S. aureus (MRSA) consisted of 461 (78%) multiresistant and 127 (22%) nonmultiresistant isolates. The nonmultiresistant MRSA consisted of epidemic MRSA-15 and community-associated MRSA. The community-associated MRSA was detected in all hospitals with MRSA, indicating its establishment in Kuwaiti hospitals. The proportion of isolates resistant to gentamicin, kanamycin, erythromycin, tetracycline, ciprofloxacin, fusidic acid and trimethoprim was higher among MRSA than methicillin-susceptible S. aureus (MSSA) isolates. Twenty-four and 22% of MRSA and MSSA isolates, respectively, expressed reduced susceptibility to vancomycin (minimum inhibitory concentration = 3–4 mg/l). Conclusion: The study revealed the presence of methicillin resistance in 32% of S. aureus isolated in Kuwaiti hospitals and revealed an increase in the number of MRSA and MSSA with reduced susceptibility to vancomycin.

Crohn's disease presenting as pyogenic liver abscess with review of previous case reports.

A 40-yr-old male doctor from India presented with pyogenic liver abscesses as the first manifestation of Crohns disease. The Crohns disease itself was limited to the appendix and the adjacent cecum and could be diagnosed only 6 months after the presentation with liver abscess. This single case highlights three unusual features of Crohns disease, and stresses the importance of meticulous search for a cause for pyogenic liver abscess when it occurs in an otherwise healthy adult.

Molecular Characterization of Nitroimidazole Resistance in Metronidazole-Resistant Bacteroides Species Isolated from Hospital Patients in Kuwait

Objectives: The aim of this study was to screen for infections caused by metronidazole (MTZ)-resistant Bacteroides spp., and to characterize the genes that encode the MTZ resistance. Materials and Methods: A total of 7 MTZ-resistant Bacteroides spp. were isolated from 5 patients with MTZ-resistant infections. These organisms were investigated for carriage of genes that encode MTZ resistance. The presence of these genes was investigated by PCR and the PCR products were subjected to PCR-RFLP analysis. Results: The strains were MTZ-resistant with minimum inhibitory concentrations of >32 µg/ml. The presence of nim genes was indicated by PCR in all 7 strains. PCR-RFLP analysis of the nim gene products demonstrated two of the five reported resistance genes, nimA–nimE. These two resistance genes were nimE in 5 of the 7 isolates and nimA in 2 strains. Conclusion: MTZ-resistant Bacteroides spp. have been isolated from patients in Kuwait. Nim genes, specifically nimE and nimA, mediate the drug resistance in these isolates. The methods used in detecting these genes are rapid, accurate and relatively inexpensive and could be adopted easily to help in monitoring emergence of MTZ resistance determinants in Kuwait.

Antimicrobial resistance in clinical isolates of Streptococcus pneumoniae in a tertiary hospital in Kuwait, 1997–2007: Implications for empiric therapy

OBJECTIVE This study evaluated antibiotic resistance trends in Streptococcus pneumoniae isolated in a tertiary hospital in Kuwait and its implications for empiric therapy. MATERIALS AND METHODS Antimicrobial susceptibility of 1353 strains of S. pneumoniae isolated from clinical specimens during 1997-2007 was performed by disc diffusion method. MIC was determined by E test. The results were compared for 1997-2001, 2002-2005 and 2006-2007. RESULTS The prevalence of resistance for the respective periods were as follows: penicillin, 51.3%, 61.3% and 54.5%; erythromycin, 31.2%, 36.7% and 37.7%; tetracycline, 30.8%, 45.3% and 41.3%; co-trimoxazole, 49.5%, 58.5% and 62.8%; clindamycin, 20.4%, 20.6% and 24.5% and chloramphenicol, 8.1%, 8.9% and 3.7%. All were susceptible to vancomycin and rifampicin. For oxacillin-resistant isolates, penicillin resistance was rare (0.8%) with the new non-meningeal breakpoint. However, using the meningeal breakpoints, resistance increased for penicillin from 0.6%, to 28.7%, for cefotaxime from none to 16.5%, and for ceftriaxone from none to 7%. Intermediate resistance to meropenem increased from 1.7% to 22.4%. Multiple drug resistance increased from 22.4% to 37.8%. CONCLUSION The study demonstrated that antimicrobial resistance of S. pneumoniae is increasing in Kuwait. However, the results of MIC determinations indicated that penicillin can still be used for therapy of non-meningeal infections. High prevalence of erythromycin resistance suggests that therapy of pneumonia with a macrolide alone may result in failure and should be based on results of susceptibility testing.

Relative Resistance of Pneumococci to Penicillin: Detection and Prevalence in Kuwait

When 457 isolates of Streptococcus pneumoniae (pneumococci) from clinical specimens were tested by the agar diffusion method with 1-µg oxacillin discs, to differentiate penicillin-s

Isolation and Characterization of Coagulase-Negative Methicillin-Resistant Staphylococcus aureus from Patients in an Intensive Care Unit

Objective: To report the isolation and characterization of four coagulase-negative methicillin-resistant Staphylococcus aureus isolated from patients admitted to the ICU of a Kuwait hospital by bacteriological and molecular methods. Methods: The isolates were characterized by cultural characteristics, Gram stain, catalase, coagulase, DNase and biochemical tests and typed by a combination of antibiogram and pulsed-field gel electrophoresis to evaluate their relatedness. Results: These isolates were gram-positive cocci in clusters, catalase, DNase and slide coagulase-positive but tube coagulase-negative. They gave negative results for ornithine decarboxylase and pyrrolidonyl-arylamidase tests, which indicated that these were not Staphylococcus lugdunensis or Staphylococcus schleiferi, and were identified as S. aureus by API Staph. They had identical antibiograms and pulsed-field gel electrophoresis patterns which suggested that they had a common origin. Conclusion: The results highlight the need to complement the coagulase tests with other tests such as DNase and biochemical tests to correctly identify S. aureus. Coagulase-negative S. aureus appears to be an increasing problem that clinical laboratories should be aware of. They are as virulent as those producing coagulase and can colonize, cause infections and spread among patients.

Pneumococci Relatively Resistant to Penicillin

Review of cases with meningitis in a general hospital in Kuwait showed high prevalence of relatively resistant Streptococcus pneumoniae (RRSP). During an observation period of 3 yea

Cerebrospinal Fluid Lactate Is Useful in Differentiating Viral from Bacterial Meningitis

Cerebrospinal fluid (CSF) lactate was studied in 63 consecutive infants and children with suspected bacterial meningitis. Levels of CSF lactate above 3 mmol/l were present in 14 out of 16 children wit

Rising Incidence of Beta-Lactam Resistance among Pneumococci in Kuwait: Failure of Cefotaxime Therapy in Pneumococcal Meningitis

Objective: Pneumococcal resistance to antimicrobial agents has become a global problem. This study was done to evaluate the resistance of Streptococcus pneumoniae (pneumococci) to penicillin G in Kuwait, and to assess the efficacy of other β-lactam agents (cefotaxime or ceftriaxone) in the management of invasive pneumococcal infections. Methods: Surveillance studies were done in a general teaching hospital in Kuwait for penicillin G resistance (intermediate or high level resistance) of pneumococci isolated from clinical specimens by agar diffusion method using oxacillin (1 µg) disc. In cases of pneumococcal meningitis, minimum inhibitory concentrations (MICs) of penicillin and cefotaxime were determined by agar dilution method, to differentiate intermediate resistance and high level resistance. Results: An increase in the incidence of penicillin G-resistant pneumococci from 20.6% (94 out of 457 isolates) for the period 1985–1988 to 28.5% (40 out of 140 isolates) during 1992–1994 and 38.3% (43 out of 112 isolates) during 1995/96 was observed. During the period 1992–1994, 40–45% (7 out of 16 isolates) blood culture isolates of pneumococci were intermediate or highly resistant to penicillin. Therapy with cefotaxime or ceftriaxone produced a positive outcome in 6 of the 7 patients. However, failure of cefotaxime therapy to achieve a cure was noted in 1 patient who had systemic lupus erythematosus and intermediate resistant (penicillin MIC 0.5 mg/l; cefotaxime MIC 1 mg/l) pneumococcal septicaemia complicated with meningitis. A cure was however achieved with the addition of chloramphenicol to the regimen. Conclusion: Resistance of pneumococci to penicillin G and other β-lactam agents is increasing in Kuwait. Penicillin-resistant pneumococcal bacteraemia in an immunosuppressed setting, if managed with cefotaxime or ceftriaxone, should be given high doses (cefotaxime 12 g/day or ceftriaxone 4 g/day) from the beginning. Cases of pneumococcal meningitis with cefotaxime-intermediate resistant strains (MIC 0.5–1 mg/l) on monotherapy consisting of cefotaxime or ceftriaxone should be viewed with caution. Chloramphenicol or vancomycin with rifampicin should be added to the regimen if therapeutic failure is suspected.