Comparative in vitro activity of tigecycline and other antimicrobial agents against Shigella species from Kuwait and the United Arab of Emirates

Shigella species isolated from stool samples of symptomatic patients of all age groups at the Mubarak Al Kabir Hospital and Infectious Diseases Hospital, Kuwait and Tawam Hospital, UAE during a 2-year period were investigated for their susceptibility to tigecycline and several other antibiotics by determining the minimum inhibitory concentrations [MICs] using the E test method. A total of 100 and 42 strains were collected from UAE and Kuwait, respectively. The extent of drug resistance in the Shigella spp. isolates from these two countries was analyzed by criteria recommended by the Clinical and Laboratory Standards Institute [CLSI]. Amikacin, cefotaxime, cefuroxime, ciprofloxacin, imipenem, meropenem, piperacillin-tazobactam and tigecycline had excellent activities against all isolates from UAE and Kuwait with MIC[90s] of 12, 0.094, 4, 0.012, 0.25, 0.032, 3 and 0.25micro g/ml and 4, 1, 4, 0.125, 0.38, 0.19, 3 and 0.25 micro g/ml, respectively. Half of all isolates from both countries were resistant to ampicillin. None of the isolates in Kuwait was resistant to amoxicillin-clavulanic acid compared with 22% in UAE. Resistance to chloramphenicol was recorded in 50 and 36% of the isolates in Kuwait and UAE, respectively. The percentages of non-susceptibility to trimethoprim-sulfamethoxazole and tetracycline were very high in Kuwait and UAE [76% vs. 92% and 76% vs. 98%, respectively]. Notably, one isolate, S. flexneri, from UAE had reduced susceptibility to ciprofloxacin [MIC, 0.25 micro g/ml]. Four [2.8%] of the isolates were ESBL producers by the E test ESBL method but could not be confirmed by PCR using primers for bla[tem], BLA [SHV] and- bla[tem]. In conclusion, Shigella spp. isolated from symptomatic patients in Kuwait and the UAE demonstrated high

Surveillance of antibacterial resistance in Staphylococcus aureus isolated in Kuwaiti hospitals

To investigate the prevalence of antibiotic resistance among Staphylococcus aureus isolated in Kuwaiti hospitals. 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. 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 non-multiresistant 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]. 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

Plasmid-mediated high-level ceftriaxone resistance in a Salmonella enterica serotype typhimurium isolate

We evaluated ion exchange chromatography [IEC] on the Jeol Aminotac 500 analyzer for total homocysteine [tHcy] determination and compared it with an immunoassay method using fluorescence polarization on an Abbott IMx analyzer. IEC method validation [linearity, limit of detection, precision, interference] was made according to the French Biology Society guidelines [Societe Fran‡aise de Biologie Clinique]. Moreover, during a 2-month period, 55 plasma samples from patients scheduled for routine tHCy measurement were assayed by both methods for determining correlation. The IEC method was found linear up to at least 190 micro mol/l, and the limit of detection was 1.6 micro mol/l. Precision was studied with 3 controls at 6, 15 and 30 micro mol/l. Intra-assay coefficients of variation [n = 14] were 8.3, 3.1 and 2.3%, respectively, and inter-assay coefficients of variation [n = 15] were 9.6, 5.1 and 4.9%, respectively. No interference was found with other sulfur-containing amino acids [methionine, cysteine]. An excellent agreement was found between IEC and fluorescence polarization [Deming regression; y = 0.99x - 1.23; r = 0.97; p < 0.001]. The IEC method for tHcy measurement shows adequate precision and correlates highly with the IMx assay. The IEC method is more time-consuming but less expensive in reagent cost and allows simultaneous determination of plasma methionine concentration which may help to explain the underlying mechanism responsible for hyperhomocysteinemia

Incidence of bloodstream infections in a speciality hospital in Kuwait: 8-year experience

To determine the frequency of isolation and antibiotic-susceptibility patterns of clinically significant bacterial pathogens isolated from blood. The study was conducted over a period of 8 years [1995-2002] at Infectious Diseases Hospital [DH], Kuwait. Demographic and clinical data were obtained from medical records. 18,535 blood cultures were analyzed. Disk diffusion method was used to perform antibiotic-susceptibility testing. Minimum inhibitory concentrations of 9 antimicrobials were determined using E-test. Double disk [potentiation] test and E-test ESBL strips were used to detect the production of extended-spectrum beta-lactamases [ESBLs]. Salmonella spp. and Brucella spp. were predominant blood isolates, and represented 60.6 and 30.0% of all clinically significant episodes of bloodstream infections, respectively. Among the Salmonella, Salmonella enterica serotypes typhi and paratyphi A were most frequently isolated. The percentage of multidrug resistance [MDR] among them varied from 22 to 51%. A high percentage [40%] of MDR S. enterica serotypes typhi and paratyphi A also showed reduced susceptibility to ceftriaxone and ciprofloxacin. During the study period, Salmonella spp. and Brucella spp. were predominant blood isolates. MDR S. enter/ca serotypes typhi and paratyphiA, with reduced susceptibility to ceftriaxone and ciprofloxacin, are among the most frequent causes of bloodstream infections in IDH, suggesting the need to monitor their susceptibility