Vincent O. Rotimi

Emergence of CTX-M-15 type extended-spectrum β-lactamase-producing Salmonella spp. in Kuwait and the United Arab Emirates

Cephalosporins are major antimicrobials used to treat serious Salmonella infections. However, their effectiveness is being compromised by the emergence of extended-spectrum beta-lactamases (ESBLs). The genetic determinants encoding ESBL in Salmonella spp. isolated from patients in Kuwait and United Arab Emirates (UAE) were studied over a 2 year period. Out of a total of 407 isolates, 116 isolates possessed the resistance phenotypes consistent with possible ESBL production. Of these, 69 (59.5 %) were ESBL positive. PCR and sequencing were used to determine the genetic determinant(s) responsible for ESBL phenotypes. A total of 14 (12.1 %) and 29 (24.6 %) isolates were CTX-M-15 ESBL producers and TEM producers, respectively. Ten CTX-M-15 producers carried the insertion sequence ISEcpI gene. PFGE analysis revealed identical profiles in 4 of the 13 Kuwaiti strains. This study reports the presence of the bla(CTX-M-15) gene in Salmonella spp. and Salmonella enterica serotype Typhi from Kuwait and UAE for what is believed to be the first time. This is of great concern as the gene is also found in association with the ISEcpI gene, which may easily facilitate its spread. These isolates originated mostly from non-Kuwaiti Arabs rather than from people of Asian origin.

Spectrum and antibiotic resistance of uropathogens isolated from hospital and community patients with urinary tract infections in two large hospitals in Kuwait.

Objectives: To determine the spectrum of microbial etiology and antibiotic resistance pattern of the uropathogens that cause urinary tract infections in 2 large teaching hospitals in Kuwait over a period of 1 year. Materials and Methods: The Vitek identification card system was used to identify the uropathogens. Susceptibility of the isolates against 18 antibiotics was performed by the microbroth dilution method using the Vitek automated system. In addition, gram-positive bacteria were tested in parallel by the disk diffusion technique. Results: The six overall most common isolates were: Escherichia coli, accounting for 47% of isolates in both hospitals, followed by Candida spp. (10.8%), Klebsiella pneumoniae (9.6%), Streptococcus agalactiae (GBS; 9.5%), Enterococcusfaecalis (4.2%) and Pseudomonas aeruginosa (4.1%). Amikacin provided the widest coverage amongst all the antibiotics tested followed by ciprofloxacin, gentamicin and piperacillin-tazobactam. For the gram-negatives, high resistance (26–63%) to the β-lactam antibiotics was noted, especially to ampicillin, amoxicillin-clavulanic acid, cephalothin and cefuroxime. Resistance to trimethoprim-sulfamethoxazole was also high. None of the enterococci was resistant to the glycopeptides, but 38–60% of the Staphylococcus haemolyticus were resistant to vancomycin or teicoplanin. Conclusion: These data show the high level of antimicrobial resistance amongst the uropathogens causing urinary tract infection in the two hospitals studied.

Factors predisposing to urinary tract infection after J ureteral stent insertion

PURPOSE We determined the group of patients most likely to have bacterial infection or colonization of J stents inserted to relieve ureteral obstruction. MATERIALS AND METHODS Midstream urine from 250 consecutive patients who required indwelling J stent insertion obtained before stent insertion and on the day of stent removal was analyzed by microbiological testing. At stent removal 3 to 5 cm. of the stent tip located inside the bladder was also sent for culture. Patient sex, duration of stent insertion and systemic disease, such as diabetes mellitus, chronic renal failure or diabetic nephropathy, were recorded. Patients without systemic disease were classified as normal. The rates of bacteriuria, stent colonization and symptomatic urinary tract infection were compared in patients with and without systemic disease. RESULTS Of the 250 patients studied 180 (72%) were men and 70 (28%) were women, while 152 (60.8%) had no systemic disease, 27 (10.8%) had diabetes mellitus, 53 (21.1%) had chronic renal failure and 18 (7.2%) had diabetic nephropathy. The bacteriuria rate was 4.2% for stents removed within 30 days and 34% for stents removed after 90 days (p <0.001). Overall the bacteriuria rate in women was 24.3% compared with 13.9% in men (p <0.06). The rate of bacteriuria in normal patients was significantly lower (3.3%) than in patients with diabetes mellitus, chronic renal failure and diabetic nephropathy (33.3%, 39.6% and 44.4%, respectively, p <0.001). The colonization rate of the tip of the stent was higher in women (64.3%) than in men (34.7%). The stent was removed prematurely in 9 of the 250 patients (3.6%) because of septicemia, including 7 women (77.8%) with systemic disease. CONCLUSIONS The risk of bacteriuria and colonization of the J stent tip is significantly enhanced by the duration of stent retention, patient sex and the systemic disease, such as diabetes mellitus, chronic renal failure and diabetic nephropathy. These categories of patients should undergo shorter stent retention, antimicrobial prophylaxis and careful followup to minimize infectious complications.

Wide Dissemination of GES-Type Carbapenemases in Acinetobacter baumannii Isolates in Kuwait

ABSTRACT Acinetobacter baumannii is an opportunistic pathogen that is an important source of nosocomial infections. Production of extended-spectrum β-lactamases (ESBLs) of the GES type in A. baumannii has been increasingly reported, and some of these GES-type enzymes possess some carbapenemase activity. Our aim was to analyze the resistance determinants and the clonal relationships of carbapenem-nonsusceptible A. baumannii clinical isolates recovered from hospitals in Kuwait. A total of 63 isolates were analyzed, and all were found to be positive for blaGES-type genes. One isolate harbored the blaGES-14 gene encoding an ESBL with significant carbapenemase activity, whereas the other isolates harbored the blaGES-11 ESBL gene. Thirty-three isolates coharbored the blaOXA-23 and blaGES-11 genes. Analyses of the genetic locations indicated that the blaGES-11/-14 genes were plasmid located. It is noteworthy that the blaOXA-23 and blaGES-11 genes were colocated onto a single plasmid. Nine different pulsotypes were observed among the 63 isolates. This study showed the emergence of GES-type ESBLs in A. baumannii in Kuwait, further suggesting that the Middle East region might be a reservoir for carbapenemase-producing A. baumannii.

Comparison of two matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry methods and API 20AN for identification of clinically relevant anaerobic bacteria

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid microbial diagnosis at relatively low cost and can be considered an alternative to conventional biochemical and molecular identification systems in clinical microbiological laboratories, including anaerobe laboratories. Two commercially available MALDI-TOF MS systems, Bruker Microflex MS and bioMérieux VITEK MS, were evaluated for the identification of 274 isolates of clinically significant anaerobic bacteria recovered from routine cultures of clinical specimens in parallel with blinded comparison with conventional biochemical (API 20AN) or molecular methods. All were recovered cultures obtained from patients attending the Mubarak Al Kabir Hospital, Kuwait, during a 6 month period. Discrepant results after two attempts at direct colony testing had failed to provide acceptable MALDI-TOF identification were resolved by gold-standard 16S gene sequencing. The VITEK MS gave high-confidence identification of the 274 isolates, all of which were correctly identified. The Bruker Microflex MS system also gave high-confidence identification for 272 of the 274. After discrepancy testing, the Bruker MS results agreed with biochemical or molecular methods for 89.1 % of the isolates at species level and 10.2 % at genus level (0.72 % were misidentified). The level of agreement with the VITEK MS was 100 % at both species and genus level; no isolates were misidentified. Our data suggest that implementation of MALDI-TOF MS as a first step for identification will shorten the turnaround time and reduce the cost in the anaerobe laboratory.

A study of the microbiology of diabetic foot infections in a teaching hospital in Kuwait

The purpose of this study was to determine the microbiological profile of diabetic foot infections (DFIs) and assess the antibiotic susceptibility of the causative agents. Data were obtained from a retrospective analysis of DFI samples collected from June 2007 to July 2008. Specimens were cultured using optimal aerobic and anaerobic microbiological techniques, and antibiotic susceptibility testing was performed according to the methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Extended-spectrum β-lactamase (ESBL) production was measured using the double disk synergy test and the ESBL Etest. A total of 440 patients were diagnosed with DFIs during this period, and a total of 777 pathogens were isolated from these patients with an average of 1.8 pathogens per lesion. We isolated more Gram-negative pathogens (51.2%) than Gram-positive pathogens (32.3%) or anaerobes (15.3%). Polymicrobial infection was identified in 75% of the patients. The predominant organisms isolated were members of the Enterobacteriaceae family (28.5%), Pseudomonas aeruginosa (17.4%), Staphylococcus aureus (11.8%), methicillin-resistant S. aureus (7.7%), anaerobic Gram-negative organisms (10.8%), and Enterococcus spp. (7%). Vancomycin was the most effective treatment for Gram-positive bacteria, and imipenem, piperacillin-tazobactam and amikacin were the most effective treatments for the Gram-negative bacteria. In conclusion, DFI is common among diabetic patients in Kuwait, and most of the cases evaluated in this study displayed polymicrobial etiology. The majority of isolates were multi-drug resistant. The data gathered in this study will be beneficial for future determinations of empirical therapy policies for the management of DFIs.

Prevalence of Chlamydia trachomatis, Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum Infections and Seminal Quality in Infertile and Fertile Men in Kuwait

This study was undertaken to determine the prevalence of Chlamydia trachomatis, mycoplasmas, and ureaplasmas in semen samples of infertile compared with fertile men and to evaluate the seminological variables of semen from infected and noninfected men. A total of 127 infertile and 188 fertile men seen in a maternity hospital clinic were recruited into the study over a period of 14 months. Specimens were obtained by masturbation and examined for the presence of Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium, and C trachomatis by polymerase chain reaction. Semen analysis was performed according to World Health Organization guidelines. U urealyticum, M hominis, M genitalium, and C trachomatis were demonstrated in the semen samples of 31 (24.4%) vs 49 (26.1%), 22 (17.1%) vs 61 (32.4%), 6 (4.7%) vs 6 (3.2%), and 5 (3.9%) vs 7 (3.7%), respectively, of infertile and control men. Mixed infections were detected in 14 (11%) of infertile and 29 (15.4%) of fertile men. The infertile men positive for M hominis had semen samples that showed statistically significant differences in the mean of sperm pH and leukocyte count between infected and uninfected men (P < .03 and P < .001, respectively). Similarly, there was statistically significant difference in the leukocyte counts of M genitalium and C trachomatis in infected compared with uninfected men. A similar trend was noted in infected fertile compared with uninfected men. The difference in prevalence of these urogenital pathogens among infertile compared with fertile men was not statistically significant. However, genital mycoplasmas and chlamydial infections appeared to influence semen quality negatively.

Emergence of Tigecycline and Colistin Resistance in Acinetobacter Species Isolated from Patients in Kuwait Hospitals

Abstract The development of resistance is a compelling reason for reviewing administration of antibiotics. Recently, most Acinetobacter infections are caused by multidrug-resistant (MDR) strains which have necessitated the use of tigecycline or colistin. This study was undertaken to determine the susceptibility of Acinetobacter spp. To these and other drugs. A total of 250 Acinetobacter isolates were collected from the 8 government hospitals over a period of 6 months. Susceptibility to 18 antibiotics, including tigecycline and colistin, was investigated by determining their minimum inhibitory concentrations using e test. Of the 250 isolates, 13.6% and 12% were resistant to tigecycline and colistin. A total of 25.2% and 37.2% were resistant to imipenem and meropenem, respectively. Of the 250 isolates 88.4% were MDR. This relatively high prevalence of tigecycline and colistin-resistant isolates indicates an emerging therapeutic problem which may severely compromise the treatment of MDR Acinetobacter spp. infections in Kuwait.

Rapid identification of pathogens directly from blood culture bottles by Bruker matrix-assisted laser desorption laser ionization-time of flight mass spectrometry versus routine methods

The use of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identification of microorganisms directly from blood culture is an exciting dimension to the microbiologists. We evaluated the performance of Bruker SepsiTyper kit™ (STK) for direct identification of bacteria from positive blood culture. This was done in parallel with conventional methods. Nonrepetitive positive blood cultures from 160 consecutive patients were prospectively evaluated by both methods. Of 160 positive blood cultures, the STK identified 114 (75.6%) isolates and routine conventional method 150 (93%). Thirty-six isolates were misidentified or not identified by the kit. Of these, 5 had score of >2.000 and 31 had an unreliable low score of <1.7. Four of 8 yeasts were identified correctly. The average turnaround time using the STK was 35 min, including extraction steps and 30:12 to 36:12 h with routine method. The STK holds promise for timely management of bacteremic patients.

Etiology and Antibiotic Susceptibility Patterns of Community- and Hospital-Acquired Urinary Tract Infections in a General Hospital in Kuwait

Objective: Our purpose was to determine the bacterial profile and prevalence of antibiotic resistance patterns of uropathogens, as well as evaluate the problem with extended-spectrum β-lactamase (ESBL) producing isolates, causing urinary tract infections (UTIs) in Al-Amiri Hospital, Kuwait, over a 3-year period. Materials and Methods: Isolates (56,505) from symptomatic UTI cases from January 2005 to December 2007 were identified by conventional methods and the VITEK identification card system. Antimicrobial susceptibility testing was performed by disk diffusion method for Gram-positive organisms and an automated VITEK 2 machine for Gram-negative organisms. ESBL production by the Enterobacteriaceae was detected by the double-disk diffusion method and VITEK-2 system. Results: Significant bacteriuria was detected in 15,064 (26.6%) of the 56,505 urine samples. Escherichia coli accounted for 4,876 (54.9%) from community-acquired UTI (CA-UTI) and 2,253 (36.4%) from hospital-acquired UTI (HA-UTI), followed by Streptococcus agalactiae (1,129, 12.7%) and Klebsiella pneumoniae (962, 10.8%) from CA-UTI cases. Candida spp. (973, 15.7%) and K. pneumoniae (747, 12.1%) were the second and third most prevalent isolates, respectively, in HA-UTI. High resistance rates were observed among the Enterobacteriaceae against ampicillin, cephalothin, ciprofloxacin, piperacillin and trimethoprim-sulfamethoxazole. About 855 (12%) and 291 (17%) of E. coli and K. pneumoniae, respectively, were resistant to ≧4 antibiotics. The prevalence of ESBL-producing E. coli and K. pneumoniae in CA-UTI was 12 and 17% and in HA-UTI 26 and 28%, respectively. Conclusion: A high percentage of the uropathogens causing UTI in the Al-Amiri Hospital setting was highly resistant to the first- and second-line antibiotics for the therapy of UTI. ESBL-producing bacteria are highly prevalent in our hospital.