Molecular detection of carbapenem resistance genes in rectal swabs from patients in Gulf Cooperation Council hospitals.

BACKGROUND: Gram-negative organisms harbouring carbapenem resistance genes (CRGs) are spreading globally, including in Gulf Cooperation Council (GCC) countries. However, relatively few data are available about carriage of CRGs in hospitalized patients in this region. AIM: To determine prevalence of CRG carriage and risk factors for colonization among patients in GCC hospitals. METHODS: Rectal swabs were obtained from ∼50 intensive care unit (ICU) patients from each of 11 hospitals in five GCC countries between March and November 2019. The swabs were tested for the presence of blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48 CRG using a commercial polymerase chain reaction test. Data on risk factors for colonization were collected and analysed. FINDINGS: Of 529 specimens screened, 138 (26.1%) were positive for one or more CRGs. The positivity rates among the hospitals ranged from 8.0% to 67.3%; ∼20% of the positive specimens harboured ≥2 CRGs. The most common CRG detected was blaOXA-48, which was present in 82 specimens (15.5%). Additional CRGs included blaNDM, blaVIM, blaKPC, and blaIMP either alone or in combination. Overall, 31.1% of patients on antibiotics on admission to the ICU were positive for CRGs compared to 16.5% not on antibiotic therapy (P < 0.001). CRG detection was also more common among patients aged >65 years (P = 0.027) and increased with hospital length of stay (P = 0.025). CONCLUSION: The rate of CRGs detected in hospitalized patients in GCC countries varied considerably. Prior antibiotic exposure, increasing age, and prolonged length of stay were associated with CRG detection.

Results from the Survey of Antibiotic Resistance (SOAR) 2015-17 in the Middle East (Kuwait, Lebanon and Saudi Arabia): data based on CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints.

OBJECTIVES: To determine antibiotic susceptibility of Streptococcus pneumoniae and Haemophilus influenzae isolates from community-acquired respiratory tract infections (CA-RTIs) collected in 2015-17 from Kuwait, Lebanon and Saudi Arabia. METHODS: MICs were determined by CLSI broth microdilution and susceptibility was assessed using CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. RESULTS: A total of 139 S. pneumoniae isolates were collected from four centres in Kuwait, Lebanon and Saudi Arabia in 2015-17 and 55 H. influenzae isolates were collected and analysed from Saudi Arabia over the same time period. Pneumococci from all three countries were commonly non-susceptible to penicillin based on CLSI oral or low-dose IV penicillin using EUCAST breakpoints (39% in Kuwait to 57.1% in Lebanon) but by CLSI IV and EUCAST high-dose breakpoints most isolates were susceptible (∼90% in Kuwait and Saudi Arabia, and 100% in Lebanon). Isolates from Lebanon were highly susceptible to most other antibiotics (>90%) except cefaclor, oral cefuroxime and cefpodoxime (EUCAST breakpoints only). Overall, susceptibility was significantly lower in Kuwait and Saudi Arabia than Lebanon. Although all H. influenzae isolates (Saudi Arabia only) were ß-lactamase negative, 3.6% and 12.7% were ampicillin resistant by CLSI and EUCAST breakpoints, respectively. Otherwise susceptibility was high in H. influenzae. The application of different EUCAST breakpoints for low and higher doses for some of the antibiotics (amoxicillin, amoxicillin/clavulanic acid, ampicillin, penicillin, ceftriaxone, clarithromycin, erythromycin, levofloxacin and trimethoprim/sulfamethoxazole) allowed, for the first time in a SOAR study, the effect of raising the dosage on susceptibility to be quantified. CONCLUSIONS: Relatively low antibiotic susceptibility was observed in S. pneumoniae from Kuwait and Saudi Arabia in contrast to Lebanon, where rates of susceptibility were generally higher. Isolates of H. influenzae from Saudi Arabia were susceptible to most antibiotics. These factors are important in decision making for empirical therapy of CA-RTIs.

Effect of the introduction of pneumococcal conjugate vaccines on serotype prevalence in Kuwait and Saudi Arabia.

BACKGROUND: Streptococcus pneumoniae infection is a major cause of morbidity and mortality. Although pneumococcal disease burden in Kuwait and Saudi Arabia is considered high, comprehensive surveillance data on pneumococcal conjugate vaccine (PCV) effects are lacking. METHODS: Sterile isolates from patients in Kuwait (2003-2016) and Saudi Arabia (aged ≤5 years, 2000-2010; all patients, 2011-2015) were included. Serotyped isolates were classified by inclusion in the 7-valent (PCV7) or 13-valent PCV (PCV13); isolates of other serotypes were classified as "non-PCV13". Isolate frequency (number of isolates/year) and classification of isolates according to vaccine type were assessed by period (before PCV, after PCV7, and after PCV13 introduction). RESULTS: In Kuwait, the frequency of collected isolates was highest after PCV7 introduction. Decreased frequency of PCV7 serotypes was seen after PCV13 introduction compared with before PCV and after PCV7 introduction. Increased frequency of the 6 additional serotypes in PCV13 and non-PCV13 serotypes was observed after PCV7 introduction with a subsequent decrease in the 6 additional serotypes in PCV13 and non-PCV13 serotypes after PCV13 introduction. The percentage of isolates of vaccine serotypes in Kuwait decreased over time. In Saudi Arabia, the frequency of collected isolates was highest after PCV7 introduction. An increased frequency of PCV7 serotypes was observed after PCV7 introduction, with a further decrease after PCV13 introduction. For the 6 additional serotypes in PCV13, an increased frequency was seen after PCV7 and PCV13 introduction compared to before PCV introduction. For non-PCV13 serotypes, an increased frequency was observed after PCV13 introduction compared to after PCV7 introduction. The percentage of isolates covered by PCV13 serotypes was similar across periods, while a substantial decrease in isolates covered by PCV7 was seen after PCV13 introduction. CONCLUSION: PCVs in Kuwait and Saudi Arabia resulted in decreased frequency of some vaccine serotypes and an emergence of some non-PCV13 serotypes. Further investigation is warranted.

Comparison of two molecular methods and an automated liquid culture system for the early detection of Mycobacterium tuberculosis from both pulmonary and extrapulmonary specimens in Kuwait.

OBJECTIVE/BACKGROUND: Molecular methods for the detection of Mycobacterium tuberculosis (MTB) are widely used for the early diagnosis of tuberculosis (TB). The objectives of this study were to evaluate the performance of two molecular techniques for the detection of MTB for both pulmonary and extrapulmonary specimens in comparison with conventional culture techniques in Kuwait and to correlate the results with clinical and histopathological diagnosis. METHODS: A total of 9,594 consecutive pulmonary (n=5,597) and extrapulmonary (n=3,997) specimens received by the Kuwait National TB Reference Laboratory from November 2011 to December 2015 were processed for direct smear microscopy for acid-fast bacilli using a Zhiel-Neelsen stain, Xpert MTB/RIF assay, ProbTec polymerase chain reaction (PCR), and growth in fully automated MGIT 960 system tubes. The clinical and histopathological diagnoses were correlated with the results. RESULTS: For pulmonary specimens, the overall sensitivity and specificity of both molecular methods together were 90.7% and 99.7%, respectively. The sensitivity and specificity of the Xpert MTB/RIF assay were 90.1% and 99.4%, respectively. The sensitivity and specificity of ProbTec PCR were 86% and 99.6%, respectively. For extrapulmonary specimens, the overall sensitivity and specificity of both molecular methods together were 87% and 97.8%, respectively. The sensitivity and specificity of Xpert MTB/RIF assay were 89.5% and 97.2%, respectively. The sensitivity and specificity of ProbTec PCR were 73% and 97.8%, respectively. When clinical and histopathological correlations were made with the assumed false-positive results from both molecular methods, the corrected sensitivity and specificity for pulmonary specimens were 91% and 99.9%, respectively, and 89.6% and 99.8% for extrapulmonary specimens, respectively. CONCLUSION: The performance of the Xpert MTB/RIF assay was superior to ProbTec PCR for the early detection of MTB from both pulmonary and extrapulmonary specimens.

In vitro activity of tigecycline against isolates collected from complicated skin and skin structure infections and intra-abdominal infections in Africa and Middle East countries: TEST 2007-2012.

Complicated skin and skin structure infections (cSSSIs) and intra-abdominal infections (IAIs) are problematic due to decreasing therapeutic options available against multidrug-resistant pathogens common among these types of infections. A total of 2245 isolates from African and the Middle Eastern (AfME) countries were collected to determine in vitro activity for tigecycline and comparators during 2007-2012 as part of the Tigecycline Evaluation Surveillance Trial program. Tigecycline was launched in the AfME in 2007 and remains active against a wide range of targeted pathogens worldwide. Isolates were recovered from cSSSI (1990) and IAI (255) from 38 sites in 11 AfME countries. Staphylococcus aureus was the most common species from cSSSI (27.9%), and the methicillin-resistant S. aureus rate was 25%. Enterococcus spp. (7.1%) and Streptococcus agalactiae (2.9%) were other common Gram-positive pathogens represented. Enterobacter spp. (14.5%), Pseudomonas aeruginosa (13.9%), Escherichia coli (11.4%), Klebsiella spp. (10.9%), and Acinetobacter spp. (7.2 %) were the most common Gram-negative species collected. Tigecycline MIC(90) values were 0.25 µg/mL against S. aureus. E. coli and Enterobacter spp. had tigecycline MIC(90) values of 1 and 2 µg/mL, respectively. E. coli was the most frequently collected species from IAI (28.3%), followed by Klebsiella spp. (20.8%), Enterococcus spp. (11.8%), and Stenotrophomonas maltophilia (6.3%). Isolates collected from IAI had the following tigecycline MIC(90) values: E. coli (1 µg/mL), Klebsiella spp. and other Enterobacteriaceae (2 µg/mL), Enterococcus spp. (0.25 µg/mL), and S. maltophilia (1 µg/mL). Tigecycline in vitro activity was observed against a broad spectrum of bacterial species, including strains resistant to other antimicrobial classes.

Value of (1-3)-ß-d-glucan, Candida mannan and Candida DNA detection in the diagnosis of candidaemia.

This study determined the value of (1,3)-ß-d-glucan (BDG), Candida mannan (MN) and Candida species-specific DNA as surrogates for diagnosis of candidaemia. Thirty-nine patients yielding Candida species in blood cultures were investigated for presence of BDG, MN and Candida species-specific DNA in serum samples. The Candida spp. bloodstream isolates included C. albicans (n = 16), C. tropicalis (n = 10), C. parapsilosis (n = 7), C. glabrata (n = 3) and C. dubliniensis (n = 3). Positivity of the three markers was as follows: Candida DNA for corresponding Candida species, 100%; BDG, 87%; MN, 59%. Despite varying sensitivities of these biomarkers, they provided a useful adjunct to the diagnosis of candidaemia.

Performance comparison of four methods for detecting multidrug-resistant Mycobacterium tuberculosis strains.

SETTING: National Tuberculosis Reference Laboratory, Kuwait. OBJECTIVE: To compare Genotype MTBDRplus (gMTBDR(+)), INNO-LiPA Rif.TB (INNO-LiPA), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing for detecting rifampicin (RMP) and/or isoniazid (INH) resistance-associated mutations in the rpoB hot-spot region (HSR-rpoB), the katG codon 315 (katG315) and the inhA regulatory region (inhA-RR) among multidrug-resistant Mycobacterium tuberculosis (MDR-TB) isolates. DESIGN: A total of 82 MDR-TB and 43 pansusceptible M.tuberculosis BACTEC 460-characterised isolates were processed using molecular techniques and the Mycobacterial Growth Indicator Tube (MGIT) 960 system. RESULTS: All susceptible strains contained wild-type sequences in target genes. RMP resistance was detected in respectively 78, 77 and 79 MDR-TB strains by gMTBDR(+), INNO-LiPA and HSR-rpoB sequencing. Two isolates with Ins514TTC mutation were detected as RMP-resistant by gMTBDR(+) but as RMP-susceptible by INNO-LiPA. One isolate with L533P mutation, detected as RMP-susceptible by gMTBDR(+), was detected as RMP-resistant by INNO-LiPA. Two of three isolates detected as RMP-susceptible by gMTBDR(+), INNO-LiPA, HSR-rpoB sequencing and the MGIT 960 system contained a I572F mutation that is outside HSR-rpoB. INH resistance was detected in respectively 76, 60, 60 and 22 MDR-TB strains by gMTBDR(+), katG315 PCR-RFLP, katG315 sequencing and inhA-RR sequencing. CONCLUSIONS: Although gMTBDR(+) accurately detected ∼ 88% of MDR-TB strains, some rpoB mutations were either missed or were outside the region of analysis of the gMTBDR(+) assay.

Invasive pulmonary aspergillosis due to Aspergillus terreus: value of DNA, galactomannan and (1->3)-beta-D-glucan detection in serum samples as an adjunct to diagnosis.

A case of invasive pulmonary aspergillosis caused by Aspergillus terreus is described. The diagnosis was based on demonstration of branched septate hyphae in a sputum specimen and isolation of the fungus in culture. The diagnosis was further supported by detection of A. terreus-specific DNA, galactomannan (GM) and (1→3)-ß-D-glucan (BDG) in consecutive serum specimens. The patient was treated for about 10 weeks with voriconazole. The decreasing levels of GM and BDG in serum samples were accompanied by symptomatic and radiological improvement. The report highlights the value of surrogate markers in the diagnosis and for monitoring the course of invasive aspergillosis during therapy.

The technical aspects and clinical significance of detecting extended-spectrum beta-lactamase-producing Enterobacteriaceae at a tertiary-care hospital in Kuwait.

Extended-spectrum beta-lactamase (ESBL) production by Enterobacteriaceae is an emerging problem. This 3-year prospective study was undertaken to determine the prevalence of such enzymes among the clinically significant isolates of the Enterobacteriaceae family gathered from patients, and to evaluate the different techniques for their detection as well as their clinical significance. Members of the Enterobacteriaceae family isolated from blood, inhibited by the third-generation cephalosporins with minimum inhibitory concentrations (MICs) of < or =2 microg/ml and MIC < or =8 microg/ml and isolates from other sources inhibited by MIC < or =8 microg/ml were also investigated for ESBL production by VITEK2 and E test. Their clinical significance in septicemic patients was analyzed. Out of 3,215 isolates, 1018 (31.7%) were ESBL-producers by both VITEK2 and E test. Of these, 428 (42%) were Klebsiella pneumoniae and 376 (37.0%) were Escherichia coli with overall prevalence rates of 13.3% and 11.7%, respectively. There were a total of 184 septicemic patients infected by ESBL-producing Enterobacteriaceae out of which 134 (73%) needed modification of therapy; most (58%) of these patients were initially on third-generation cephalosporin therapy. A total of 58 (31.5%) patients were infected by ESBL-producing blood isolates which were inhibited by cefotaxime/ceftriaxone at MICs =8 microg/ml (within the susceptibility range). Resistance to both aminoglycosides and quinolones were significantly higher among ESBLproducing isolates compared to non-producers (P <0.05). This study highlights a high prevalence of ESBL-producing Enterobacteriaceae in a major tertiary teaching hospital in our country and demonstrates that almost a third of the ESBL-producing Enterobacteriaceae blood isolates would have been released as susceptible by routine susceptibility testing; a finding inimical to optimal therapeutic success.

Secular trends in susceptibility patterns of Mycobacterium tuberculosis isolates in Kuwait, 1996-2005.

OBJECTIVE: To determine the incidence and trends of drug resistance among all Mycobacterium tuberculosis strains isolated during a 10-year period in Kuwait. DESIGN: Drug susceptibility data for M. tuberculosis isolates recovered from all pulmonary and extra-pulmonary tuberculosis (TB) patients in Kuwait from January 1996 to December 2005 were collected and analysed. Patients were divided into Kuwaiti nationals and expatriates. Prior treatment status was not recorded. RESULTS: From 1996 to 2005, 5399 non-repetitive culture-positive TB cases (56% from pulmonary sites and 44% from extra-pulmonary sites) among 917 (17%) Kuwaiti nationals and 4482 (83%) expatriates were identified throughout Kuwait. Overall resistance rates were as follows: any drug 12.5%, isoniazid (INH) 9.1%; rifampicin (RMP) 1.1%, ethambutol (EMB) 2.0%, streptomycin 4.3% and multidrug resistance (MDR) 0.9%. The resistance rates over the 10-year period remained nearly same. However, significant differences were noted in resistance rates for RMP and MDR among pulmonary vs. extra-pulmonary cases and for any drug, INH and EMB among isolates from Kuwaiti vs. expatriate patients. CONCLUSIONS: Moderate and stable single drug resistance (<10%) and low MDR rates (<1%) were found among TB cases in Kuwait. These findings highlight the importance of ongoing control measures to limit the development and spread of drug-resistant M. tuberculosis in Kuwait.

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.

Emergence and trends of penicillin non-susceptible Streptococcus pneumoniae in Saudi Arabia and Kuwait - perspective and outstanding issues.

For many years in the past Streptococcus pneumoniae was uniformly susceptible to penicillin until the sudden and unexpected emergence of clinical infections caused by penicillin-resistant S. pneumoniae (PRSP) in 1967. Within the following decade, reports of nosocomial and community outbreaks of infections due to PRSP became widespread all over the world. Recent reports suggest that the incidence of resistance rates is rising in many countries although there are geographical variations in the prevalence and patterns of resistance between countries. The problem of antibiotic resistance is further compounded by the emergence of resistance to many beta-lactam antibiotics. The first report of PRSP in Saudi Arabia was in 1991. Barely a year after, PRSP infection was reported in Kuwait in 1992. Since then, studies from various parts of these countries have recorded prevalence rates ranging from 6.2% in Riyadh to 34% in Jeddah and 20% to 56% in neighboring Kuwait. These suggest considerable variation in the prevalence of PRSP in different cities in the Saudi Kingdom and Kuwait. The mechanism of resistance is due to chromosomally mediated alteration of penicillin-binding proteins (PBPs), which are target sites for beta-lactam antibiotics. It would appear that the spread of PRSP strains in Saudi Arabia is driven by the selective pressure created by excessive use and misuse of antimicrobial agents made possible by the easy availability of these agents, often frequently obtainable over the counter. In Kuwait, irrational and misguided use of antibiotics may be the major driving force favoring the spread of PRSP. The serotypes of strains encountered in Saudi Arabia and Kuwait are almost identical, with serotypes 19, 6, 15, 14 and 23 being the most common; together they constitute about 70% of the isolates circulating in these countries. In general, almost 90% of the serotypes included in the 23-polyvalent vaccine are present in the general population. However, a much lower percentage of these serotypes is found in the conjugated vaccines, which are more relevant to our communities. This paper reviews the emergence and the steady increase in the prevalence of penicillin-resistant pneumococcal strains in Saudi Arabia and Kuwait during the last 10 years. It discusses the trends, mechanisms of resistance and factors associated with the emergence, dissemination, and colonization of resistant organisms and suggests options available to clinicians for management of infections due to PRSP.

Frequency of embB codon 306 mutations in ethambutol-susceptible and -resistant clinical Mycobacterium tuberculosis isolates in Kuwait.

SETTING: Recent reports of embB306 mutations in ethambutol-resistant and ethambutol-susceptible drug-resistant strains of Mycobacterium tuberculosis have questioned the significance of these mutations in conferring resistance to ethambutol (EMB). OBJECTIVE: To determine the occurrence of embB306 mutations in all EMB-resistant and -susceptible drug-resistant M. tuberculosis strains isolated during a specified period at a single geographical location. DESIGN: Twenty-five pansusceptible, all EMB-resistant and -susceptible M. tuberculosis strains resistant to other first-line drugs isolated in Kuwait during 2000-2003 were analyzed. The embB306 mutations were detected by PCR-restriction fragment length polymorphism and DNA sequencing. The PCR-based methods were also used for determining strain relatedness. RESULTS: None of the pansusceptible M. tuberculosis strains contained a mutation at embB306. Fifteen of 50 (30%) EMB-resistant strains but only three of 122 (2%) EMB-susceptible isolates resistant to other first-line drugs contained a mutated embB306. The EMB-susceptible isolates with embB306 mutation were resistant to isoniazid plus other drug(s). The isolates carrying similar mutations were genotypically distinct strains. CONCLUSIONS: The frequency of embB306 mutations in EMB-resistant strains compared to EMB-susceptible M. tuberculosis isolates resistant to other drugs was 15 times higher. Association of embB306 mutations in EMB-susceptible strains with isoniazid resistance and inherent problems associated with phenotypic EMB susceptibility testing suggest that these strains may actually be EMB-resistant.

Septicaemia in scald and flame burns: appraisal of significant differences.

One hundred and sixty burn patients suffering from septicaemia, hospitalized in the Al-Babtain Centre burns unit, Kuwait, between June 1992 and May 2001, were studied. Thirty-two patients (20%) had scalds and 128 (80%) flame burns, thus representing a ratio of 1:4 among septicaemic patients. There were 20 males (62.5%) in the scald group, compared to 73 (57%) with flame burns. Flame burns were significantly higher (p < 0.01) among non-Kuwaiti patients. The mean ages of the scald and flame burn patients were respectively 6.2 and 31.5 yr. The mean total body surface area burn in scalds was 20% and in flame burns 49%, which was significantly higher (p < 0.001). The 34 septicaemic episodes in 32 scald patients and 212 such episodes in 128 flame burn patients showed a significantly higher incidence in the latter group. The majority of septicaemic episodes, in scalds (82.4%) and flame burns (57.6%), were due to gram-positive organisms, mainly methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis. A significantly increased number of episodes were due to S. aureus (p < 0.001) and Enterococcus (p < 0.05) in scald patients. More surgical operations were performed in flame burn patients and survival increased significantly with an increasing number of grafting sessions (p < 0.001). The mean hospital stay in flame burn patients (56 days) was significantly higher than in scald patients (23 days) (p < 0.001). It is significant to record that all the 38 deaths (29.7%) were in flame burn septicaemic patients (p < 0.001). The scald and flame burn patients were quite distinct in their demographic and clinical characteristics. The flame burn patients were more vulnerable to septicaemia, with a high risk of mortality.

High frequency of isolation of antibiotic-resistant oral Viridans streptococci from children in Kuwait.

Antimicrobial resistance among the Viridans group of streptococci (VGS) has emerged as a hindrance to effective antibiotic therapy. Our objective was to evaluate the prevalence of antibiotic-resistant VGS in healthy children. Plaque samples were collected from tooth and tongue surfaces of 102 healthy subjects. Serially diluted samples were inoculated onto BHI agar plates and Mitis Salivarius Agar (MSA) plates and incubated as appropriate. Representative colonies were identified to species level by standard methods. Susceptibility of the VGS was performed by determining the minimum inhibitory concentrations (MICs) of 11 antibiotics using Etest. Of the 540 VGS isolates from both sites, 58% were from the tooth surfaces and 42% from the tongue. The most prevalent were S. salivarius (21.5%) and S. sanguis (16.3%). Imipenem and vancomycin had excellent activities. Resistance rates to trimethoprim, amoxicillin, piperacillin, erythromycin, cefuroxime and cephalothin, were 60.7, 40.8, 34.7, 32.6, 27.5 and 25.3%, respectively. Resistance rates to penicillin and clindamycin were 15.9% and 15.4%, respectively. The majority of the erythromycin-resistant isolates were from the tongue; 41% versus 29%. At the species level, 26% and 23% of S. salivarius and 23% and 14% of S. mutans from the tooth and tongue, respectively were resistant to penicillin. The data show species-related and site-related variations in the susceptibility pattern and an emerging high prevalence of antibiotic-resistant VGS. The difference in the susceptibilities between the species underscores the importance of accurate-identification and the need for surveillance of antimicrobial resistance among clinical isolates in our hospitals.

Sunflower seed husk agar: a new medium for the differentiation of Candida dubliniensis from Candida albicans.

A sunflower (Helianthus annuus) seed husk agar medium has been developed and evaluated for differentiation of Candida dubliniensis from Candida albicans on the basis of colony morphology and chlamydospore production. All C. dubliniensis isolates (n=40) produced rough colonies with hyphal fringes and abundant chlamydospores whereas 101 of 105 (96.2%) C. albicans isolates produced smooth colonies with no evidence of chlamydospore production. Since this medium is free from oil droplets, chlamydospores can be examined with greater clarity by Dalmau plate technique. This medium provides a simple and cost-effective tool for the presumptive differentiation of C. dubliniensis from C. albicans and is particularly suited for clinical microbiology laboratories where biochemical or molecular methods for the differentiation of these two species are not available.

Significance of atypical pathogens among community-acquired pneumonia adult patients admitted to hospital in Kuwait.

OBJECTIVES: The aim of this study is to determine the microbial etiology and severity of community-acquired pneumonia (CAP) in Kuwait. SUBJECTS AND METHODS: The severity of consecutive adult CAP cases admitted to 3 hospitals over a 1-year period was classified according to the Pneumonia Outcome Research Team (PORT) severity index. The microbial etiology was determined using standard methods for bacteria and serological tests for atypical and viral pathogens. RESULTS: The study population was 124 of the 135 admissions; 63 female, 61 male; mean age 41.3+/-18 years. The severity class distribution was: class I 31%, class II 37%, class III 17%, class IV 13%, and class V 2%. Etiological agents were identified from 44 patients (35%), with one pathogen in 31 (25%), two in 9 (7%), and three or more in 4 (3%). The most common pathogens identified were: Mycoplasma pneumoniae in 14 patients (11%), Legionella pneumophila in 10 (8%), Chlamydia pneumoniae in 8 (6%), influenza B virus in 8 (6%), influenza A virus in 5 (4%), Haemophilus influenzae in 4 (3%), Streptococcus pneumoniae in 3 (2%), Staphylococcus aureus in 3 (2%), gram-negative enterobacteria in 5 (4%), Moraxellacatarrhalis in 2 (2%), and viruses in 4 (3%). The yields from laboratory tests were 48% for paired serology, 20% from adequate sputum sample, and 3% from blood culture. CONCLUSION: Our study shows that a large percentage of mild CAP cases are admitted to hospitals in Kuwait. Atypical pathogens have a significant role in the etiology of CAP. There is overtreatment of CAP with a combination treatment consisting mainly of third-generation chephalosporins and macrolides.

In vitro activity of linezolid and other antibiotics against Gram-positive bacteria from the major teaching hospitals in Kuwait.

Multidrug-resistant Gram-positive bacteria are an increasingly pressing problem in the clinic. Consequently, linezolid, a recently introduced oxazolidinone with Gram-positive activity, was tested in comparison with 10 other antibiotics against 8103 clinically significant Gram-positive cocci by Etest, disk diffusion and Vitek methods. Linezolid demonstrated excellent activities against all isolates. Vancomycin and teicoplanin demonstrated equally excellent activity against almost all isolates. The methicillin-resistant Staphylococcus aureus (MRSA) strains were all susceptible to the glycopeptides and linezolid, but resistant to erythromycin (96%), fusidic acid (91.5%), gentamicin (84%) and clindamycin (73%). Forty one and 39% of the Streptococcus pneumoniae isolates were resistant to penicillin (MIC >0.5 microg/ml) and erythromycin (MIC >1 microg/ml), respectively. S. agalactiae susceptibility was 9% and 10% resistant to clindamycin and erythromycin, respectively. In conclusion, all the Gram-positive isolates tested were susceptible to linezolid. With its oral bioavailability profiles, it obviously holds great promise. Our data should be a useful addition to the literature from the Middle East.

Rapid detection of ethambutol-resistant Mycobacterium tuberculosis strains by PCR-RFLP targeting embB codons 306 and 497 and iniA codon 501 mutations.

Mutations at embB gene codons 306 and 497 and iniA gene codon 501 occur frequently in ethambutol (EMB)-resistant Mycobacterium tuberculosis strains worldwide. The identification of these mutations in resistant strains has been achieved by labor-intensive DNA sequencing or by tedious amplification protocols followed by restriction endonuclease digestion. In this report, we describe PCR-restriction fragment length polymorphism (RFLP)-based methods for determining substitutions at embB codons 306 and 497 and iniA codon 501 directly in BACTEC cultures of M. tuberculosis isolates. The wild-type and mutant alleles are revealed by easily interpretable and different RFLP patterns. The methods optimized initially on reference strains were tested directly on BACTEC cultures of 25 randomly selected clinical M. tuberculosis isolates, seven of which were determined to contain EMB-resistant strains by phenotypic drug susceptibility testing. The PCR-RFLP methods identified mutations in four of seven EMB-resistant strains with three isolates containing mutated embB codon 306 and one isolate containing mutated embB codon 497. The results of PCR-RFLP were confirmed by DNA sequencing. The worldwide prevalence figures for mutations at embB codons 306 and 497 and iniA codon 501 suggest that nearly half of EMB-resistant M. tuberculosis strains could be identified within one working day even in developing countries equipped with simple PCR technology instead of weeks required for phenotypic drug susceptibility testing. Further, since EMB resistance is also associated with multiple-drug resistance from some geographical locations, detection of EMB resistance may also lead to rapid identification of multidrug-resistant strains of M. tuberculosis.