Incidence of community-acquired methicillin-resistant Staphylococcus aureus carrying Pantone-Valentine leucocidin gene at a referral hospital in United Arab Emirates.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen in hospitalized patients worldwide. The present study was undertaken to identify CA-MRSA in hospitalized patients in a 350-bed tertiary care hospital in Sharjah, UAE over a 2-year period from January 2011 to December 2012. CA-MRSA was defined based on identification within first 48 h of admission in the hospital. Staphylococcal cassette chromosome (SCC) mec typing of the CA-MRSA isolates was carried out by multiplex polymerase chain reaction (PCR). Detection of PVL and mecA genes was done by PCR using the GenoType(®) MRSA test system (Hain Lifescience). Patient's clinical data and antimicrobial susceptibility pattern of the CA-MRSA isolates were also evaluated. Fifty seven of the 187 MRSA isolates were identified as CA-MRSA. All the CA-MRSA strains in our study belonged to SCCmecIV type and were positive for both PVL and mecA genes. The patients with CA-MRSA infections were young (median age, 32 years) and the majority of infections involved the skin and soft tissue (36%). Antimicrobial susceptibility pattern of the CA-MRSA isolates showed a better susceptibility profile to the non-beta-lactam antimicrobials with the exception of ciprofloxacin having 28% resistance. This study evidently strengthens the recent observation of an increase in CA-MRSA emergence among hospitalized patients in the UAE.

Misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®: a case report.

OBJECTIVE: To describe the misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®, a commonly used bacterial identification system. CLINICAL PRESENTATION AND INTERVENTION: A 35-year-old man was admitted to the Intensive Care Unit with sepsis syndrome. Three sets of aerobic blood culture samples were positive after 48 h of incubation. The isolated organism was identified as B. zoohelcum using the MicroScan WalkAway (Siemens Healthcare Diagnostics Inc., West Sacramento, Calif., USA). However, due to the rareness of the pathogen, the isolate was reidentified as B. melitensis with Vitek® 2 system and later 16S ribosomal sequence analysis confirmed the isolate as B. melitensis having 100% match. CONCLUSION: This case showed that Brucella can be misidentified using MicroScan WalkAway. Countries where brucellosis is endemic need to be careful while using such automated identification systems in order not to miss the diagnosis of Brucella.

16S rRNA gene sequence analysis of a Brucella melitensis infection misidentified as Bergeyella zoohelcum.

Misidentification of Brucella species from clinical specimens using commercial bacterial identification systems is a recurring problem. An isolate from a bacterimic patient was identified as Bergeyella zoohelcum by MicroScan Walk-Away (Siemens Healthcare Diagnostics Inc., West Sacramento, CA, USA) and as Brucella melitensis by Vitek 2 system (bioMérieux Inc., Durham, NC, USA). Because of this identification ambiguity by the two automated bacterial identification systems we performed 16S rRNA sequencing and serotyping of the isolate and confirmed it as a Brucella spp. Combining the sequence data with the Vitek 2 system data we conclude that the infection was caused by B. melitensis.

Tuberculosis and MDR-TB in the northern emirates of United Arab Emirates: a 5-year study.

In this study, we describe the prevalence of TB and occurrence of multi-drug-resistance tuberculosis (MDR-TB) in a major referral hospital belonging to the Ministry of Health in Sharjah, United Arab Emirates (UAE). A retrospective re-view of the clinical and laboratory records of 1,810 suspected cases of TB was carried out between January 2004 and September 2008. The antimicrobial susceptibility patterns of each Mycobacterium tuberculosis isolate were analyzed. During the study period, 312 M. tuberculosis culture confirmed cases were recorded; 230 were males and 82 were females. The majority of TB cases (36%) were seen among expatriates from South and Southeast Asian countries. Fifty-one active TB cases (16%) were reported in native people (Emaratis) of the country. The peak age group was between 16 and 45 years. Among first-line antituberculosis drugs, resistance to isoniazid was the most common (21%), followed by streptomycin (14%). MDR-TB was found in 15 cases (4.8%). Although the prevalence of TB in UAE is fairly low, an increasing number of cultures confirmed TB and MDR-TB among native and expatriate patients, necessitating improved vigilance in case detection, effec-tive management and prevention of MDR and XDR-TB emergence in the country.

Prevalence and antimicrobial susceptibility pattern of extended-spectrum beta-lactamase-producing Enterobacteriaceae in the United Arab Emirates.

OBJECTIVE: To investigate the prevalence and antibiotic susceptibility pattern of extended-spectrum beta-lactamases (ESBL)-producing Enterobacteriaceae among patients in the United Arab Emirates. MATERIALS AND METHODS: A total of 130 Enterobacteriaceae comprising of Escherichia coli (n = 83), Klebsiella pneumoniae (n = 45) and Klebsiella oxytoca (n = 2) was studied. Of these 130 isolates, 64 were from urine. ESBL screening was by disc diffusion and confirmatory tests for ESBL phenotype were conducted using BD Phoenix ESBL System and cephalosporin/clavulanate combination discs. Susceptibility to a panel of antibiotics was evaluated. RESULTS: Of the 130 isolates, 53 (41%) were identified as having ESBL phenotype; of these, 32 (60%) were E. coli, 20 (36%) K. pneumoniae and 2 (4%) K. oxytoca. ESBL phenotype was seen in 100% of endotracheal tubes isolates, 20 (31%) from urine, 7 (58%) from blood and 4 (80%) from catheter tips. Amikacin susceptibility was 100%. Over 90% of ESBL isolates showed resistance to aztreonam and cephalosporins. All Klebsiella isolates were carbapenem sensitive. One ESBL isolate showed intermediate resistance to imipenem and meropenem (both MIC 8 microg/ml), cefotetan (MIC 32 microg/ml) and piperacillin/tazobactam (MIC 32 microg/ml). MIC for the carbapenems was lower in non-ESBL isolates (0.034 microg/ml) than ESBL isolates (0.071 microg/ml). Resistance to gentamicin, ciprofloxacin and piperacillin/tazobactam was higher in ESBL than non-ESBL isolates (p < 0.05). CONCLUSION: A high prevalence of ESBL-producing bacteria exists among in-patients in the United Arab Emirates. Amikacin and carbapenems remain the most effective drugs, but the presence of carbapenem-resistant ESBL-producing E. coli and occurrence of multidrug resistance are of concern. Continued surveillance and judicious antibiotic usage are recommended.

Antimicrobial resistance among Streptococcus pneumoniae and Haemophilus influenzae isolates in the United Arab Emirates: 2004-2006.

BACKGROUND: Streptococcus pneumoniae and Haemophilus influenzae represent key aetiological agents in respiratory tract infections showing an increasing trend of antimicrobial resistance. We present the first report on the antimicrobial resistance in S. pneumoniae and H. influenzae isolated from patients in the United Arab Emirates. METHODS: One hundred S. pneumoniae and 102 H. influenzae strains were isolated from patients with community acquired respiratory tract infections during the study period (October 2004-March 2006). Susceptibility testing to a panel of antibiotics was conducted using disc diffusion and E test. Minimum inhibitory concentrations were interpreted using CLSI and Pharmacokinetic-pharmacodynamic (PK/PD) breakpoints. RESULTS: For S. pneumoniae isolates, 57% were penicillin susceptible while 98% were susceptible to amoxicillin/clavulanate with both interpretative criteria. Cefaclor was the least effective cephalosporin with only 57% and 43% of isolates showing susceptibility with CLSI and PK/PD breakpoints respectively. Thirty-six isolates were ofloxacin non-susceptible (intermediate and resistant); three resistant isolates were associated with high ciprofloxacin MICs (>8 mg/L). There was elevated macrolide resistance with associated high levels of erythromycin/clindamycin cross-resistance (n=22/30) suggesting predominant erm(B)-mediated resistance and 21% of isolates demonstrated multidrug resistance. For H. influenzae, 18% were beta-lactamase producers. Reduction in cefaclor and cefprozil susceptibility with PK/PD breakpoints (94.1% to 41.2% and 62.7% respectively) was seen and only 1% remained azithromycin and clarithomycin susceptible. For both pathogens, lowest susceptibility was with co-trimoxazole. CONCLUSION: These findings indicate a high level of penicillin resistance and continued usefulness of amoxicillin/clavulanate. Elevated macrolide and fluoroquinolone resistance and the occurrence of multidrug resistance indicate a need for continued surveillance.

Expression of foreign genes in Mycobacterium bovis BCG strains using different promoters reveals instability of the hsp60 promoter for expression of foreign genes in Mycobacterium bovis BCG strains.

SETTING: Optimization of BCG as a vehicle for live recombinant vaccines requires improved strategies for stable antigen expression. OBJECTIVES: To investigate the effects of various combinations of post-translational signals and promoters on expression and stability in different BCG strains. DESIGN: Plasmids were constructed using mycobacterial promoters (hsp60, 19-kDa antigen, 85A antigen--from the Mycobacterium tuberculosis complex--and the 18-kDa antigen from Mycobacterium leprae) and post-translation signals (85A antigen secretion and 19-kDa antigen acylation signals), coupled with reporter genes. RESULTS: The 19-kDa acylation signal had little effect on expression, while the 85A secretion signal enhanced markedly the levels of cell-associated product. Inclusion of the hsp60 promoter caused plasmid instability; various deletions affecting the promoter region occurred during or soon after transformation, but not during subsequent growth of the transformants, nor with other promoters. BCG Moreau appeared to be more susceptible to deletions than other BCG strains. CONCLUSIONS: The 85A signal may prove useful in optimizing gene expression in BCG, irrespective of secretion of the product. Deletions associated with the hsp60 promoter may be due to a transient lethal induction of the hsp60 promoter associated with electroporation. With intact plasmid there was no marked difference in expression between BCG strains.