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Conjugative transposons in Gram-negative bacteria have a significant role in the dissemination of antibiotic-resistance-conferring genes between bacteria. This study aims to genomically characterize plasmids and conjugative transposons carrying integrons in clinical isolates of Klebsiella pneumoniae. The genetic composition of conjugative transposons and phenotypic assessment of 50 multidrug-resistant K. pneumoniae isolates from a tertiary-care hospital (SQUH), Muscat, Oman, were investigated. Horizontal transferability was investigated by filter mating conjugation experiments. Whole-genome sequencing (WGS) was performed to determine the sequence type (ST), acquired resistome, and plasmidome of integron-carrying strains. Class 1 integrons were detected in 96% of isolates and, among integron-positive isolates, 18 stains contained variable regions. Horizontal transferability by conjugation confirmed the successful transfer of integrons between cells and WGS confirmed their presence in conjugative plasmids. Dihydrofolate reductase ( dfrA14 ) was the most prevalent (34.8%) gene cassette in class 1 integrons. MLST analysis detected predominantly ST-231 and ST-395. Bla OXA-232 and bla CTX-M-15 were the most frequently detected carbapenemases and beta-lactamases in the sequenced isolates. This study highlighted the high transmissibility of MDR-conferring conjugative plasmids in clinical isolates of K. pneumoniae . Therefore, the wise use of antibiotics and the adherence to effective infection control measures are necessary to limit the further dissemination of multidrug-resistant bacteria.

Background: Phenotypic characterization of the prevalent AmpC β-lactamases in clinical isolates is essential for making informed empirical decisions and critical for strengthening antimicrobial stewardship programmes. This study focused on assessing six assays, two in-house and four commercial phenotypic tests for detection of AmpC, to study the feasibility of making its detection a routine diagnostic microbiology laboratory activity., Methods: A total of 116 non-duplicate Gram-negative bacteria that were resistant to third-generation cephalosporins and amoxicillin/clavulanic acid, and resistant or susceptible to piperacillin/tazobactam and carbapenems, were screened by cefoxitin discs for AmpC. These isolates were subjected to two in-house (AmpC Tris-EDTA and disc approximation) methods and four commercial tests: D69C AmpC Detection Set; D72C ESBL, AmpC & Carbapenemase Detection Set; combination disc test: ESBL + AmpC Screen Disc Kit; and AmpC MIC Test Strip for confirmation of AmpC production. Ten whole-genome-sequenced AmpC-confirmed Gram-negative isolates were used as positive controls and one as a negative control., Results: The prevalence of AmpC β-lactamases was 16%. Escherichia coli was a major carrier of plasmid-mediated AmpC (26.5%), followed by Klebsiella pneumoniae (23.4%). Phenotypically, 61% of AmpCs were detected by Tris-EDTA (accuracy: 73.8%), 76% by disc approximation (accuracy: 89.2%), 75% by the D69C AmpC Detection Set (accuracy: 95.4%), 74% by the D72C AmpC, ESBL & Carbapenemase Detection Set (accuracy: 95.4%), 76% by the combination disc test (accuracy: 95.4%) and 63% by AmpC MIC Test Strip (accuracy: 87.7%). The sensitivity and specificity of D69C were 97.9% and 88.2%, respectively, and 95.9% and 93.8% for the combination disc test, while for the disc approximation test and D72C they were 93.9% and 75%, and 93.9% and 100%, respectively. Screening by cefoxitin screening was less sensitive (75%) and specific (25%). Disc approximation and the combination disc test detect AmpC in Enterobacterales and also Pseudomonas aeruginosa and Acinetobacter species., Conclusions: We recommend the in-house disc approximation test and the commercial D69C, as well as the combination disc test, as excellent tools for detection of AmpC. The cefoxitin test overcalls AmpC and cannot be considered a good stand-alone test for AmpC detection., (© The Author(s) 2023. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

Background: Data from developed/developed countries have shown that hospital-acquired blood infections (HA-BSIs) are one of the most severe nosocomial infections and constitute 20%-60% of hospitalization-related deaths. Despite the high morbidity and mortality rates and the enormous burden of health care costs associated with HA-BSIs, to our knowledge, there are few published reports on HA-BSI prevalence estimates in Arab countries, including Oman., Objectives: This study aims to explore the HA-BSI prevalence estimates over selected sociodemographic characteristics among admitted patients at a tertiary hospital in Oman over five years of follow-up. The regional variations in Oman were also examined in this study., Methods: This hospital-based cross-sectional study reviewed reports of hospital admissions over 5 years of retrospective follow-ups at a tertiary hospital in Oman. HA-BSI prevalence estimates were calculated over age, gender, governorate, and follow-up time., Results: In total, 1,246 HA-BSI cases were enumerated among a total of 139,683 admissions, yielding an overall HA-BSI prevalence estimate of 8.9 cases per 1000 admissions (95% CI: 8.4, 9.4). HA-BSI prevalence was higher among males compared to females (9.3 vs. 8.5). HA-BSI prevalence started as relatively high in the group aged 15 years or less (10.0; 95% CI 9.0, 11.2) and then declined as age increased from 36 to 45 years (7.0; 95% CI 5.9, 8.3) when it started to increase steadily with increasing age in the group aged 76 or more (9.9; 95% CI 8.1, 12.1). The governorate-specific estimate of HA-BSI prevalence was the highest among admitted patients who resided in Dhofar governorate, while the lowest estimate was reported from the Buraimi governorate (5.3)., Conclusion: The study provides supportive evidence for a steady increase in HA-BSI prevalence over age categories and years of follow-up. The study calls for the timely formulation and adoption of national HA-BSI screening and management programs centered on surveillance systems based on real-time analytics and machine learning., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2023 Marah El-Beeli et al.)

We report a 10-year-old girl who presented with acute arthritis of the left knee, which was confirmed as Lyme arthritis by serology and molecular assay. Careful history and examination were the keys to suspecting the diagnosis. The patient lived in the US for five years and her symptoms developed about a year after her return to Oman. To the best of our knowledge, this is the first case report of Lyme arthritis in Oman and the Arabian Gulf region. This case indicates the need to suspect Lyme disease in patients presenting with compatible symptoms and a history of recent travel to endemic regions., (The OMJ is Published Bimonthly and Copyrighted 2022 by the OMSB.)

Background: Complicated urinary tract infection (cUTI) is defined as an infection associated with structural, functional, or metabolic abnormalities of the genitourinary tract. These infections are caused frequently by multidrug-resistant Gram-negative bacilli. The rapid emergence of extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase (CR) producers has made the treatment of such infections increasingly more challenging., Objectives: The aims of the present study were threefold: to assess the clinical profile, trends in etiology, and antimicrobial susceptibility profile in cUTI over the past 10 years at a tertiary care center in Oman as an interrupted time series on the one hand and to develop guidelines for empirical management of such cases on the other., Materials and Methods: We conducted a retrospective analysis of cUTI in patients presenting at Sultan Qaboos University Hospital over 3 years (2008, 2013, and 2018) covering a span of 10 years. Data were obtained from the patient's electronic records in the hospital information system. Analysis was done using the Statistical Package for Social Sciences program (SPSS), version 23., Results: Among the 650 cases of cUTI, 284 (44%) were males and 366 (56%) were females, with dysuria being the most common symptom (34%). The biggest risk factor for developing cUTI was diabetes (35%). The predominant pathogen was Escherichia coli (53%), followed by Klebsiella spp. (16%), Enterococcus faecalis (7%), Pseudomonas aeruginosa (7%), Candida spp. (2%), and Enterobacter cloacae (2%). Over the years, E. coli emerged as the predominant ESBL and AmpC producer, Acinetobacter baumannii as the multidrug-resistant bug, and Klebsiella pneumoniae as the major carbapenem-resistant Enterobacterales (CRE) producer. Nitrofurantoin emerged as the most effective drug for cystitis. Aminoglycosides, piperacillin-tazobactam, and carbapenems demonstrated the highest activity with an overall resistance of less than 10%. Higher resistance (30%) was observed against cephalosporins, fluoroquinolones, and trimethoprim/sulfamethoxazole. Analysis of the 10-year trend threw up some unexpected results. As expected, resistance increased from 2008 to 2013. Surprisingly, however, antimicrobial resistance in 2018 was lower against majority of the antimicrobials compared to 2013., Conclusion: There is a paucity of data for developing evidence-based guidelines management of cUTI. Targeted antibiograms and not cumulative antibiograms are essential for promoting appropriate prescribing and optimizing patient care. The welcome decline in resistance may be attributed cascade reporting, introduction of more ID physicians. Another possibility is increased utilization of fluoroquinolones which spared the other groups of antimicrobials. Judicious heterogeneous mixing of antimicrobials should be spearheaded in both cystitis and pyelonephritis so that there is no undue pressure on one drug. We strongly recommend carbapenem-sparing protocols in treatment of cUTI when anticipating augmented resistance due to AmpC production. Synergistic combinations such as piperacillin-tazobactam plus aminoglycosides/fluoroquinolones may be prescribed. In sepsis, however, carbapenems are the drugs of choice., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Urology Annals.)

Objectives: This study aimed to determine the pattern of clinical presentations associated with Chlamydia trachomatis and Neisseria gonorrhoeae infections., Methods: A retrospective cohort study was conducted between 2015 and 2020 and included patients attending Sultan Qaboos University Hospital, Muscat, Oman, who were tested for these infections using nucleic acid amplification., Results: A total of 408 women and 89 men were included. A total of 11 infections were identified in women (n = 11, 2.7%) and 14 in men (n = 14, 15.7%). Chlamydia accounted for almost all infections in women (n = 10, 90.9%), commonly presenting with lower abdominal pain or abnormal vaginal bleeding. In men, urethral discharge/dysuria syndrome was the most common presentation and chlamydia was identified in eight men and gonorrhoea in six; a majority of all infections were seen in patients ≤35 years old., Conclusion: The relative prevalence of two common sexually transmitted infections (STIs) among patients with genitourinary symptoms at a tertiary referral hospital have been described. The pattern of their presentations will inform the design of prospective studies to improve surveillance and guide public health policy in Oman. This study highlights the need for a multi-sectoral approach involving all providers to enable comprehensive STI surveillance., Competing Interests: CONFLICT OF INTERESTS The authors declare no conflict of interests., (© Copyright 2022, Sultan Qaboos University Medical Journal, All Rights Reserved.)

Fosfomycin has emerged as a very useful antimicrobial in management of extremely drug resistant (XDR) and pan drug resistant (PDR) Klebsiella pneumoniae . In this study, we assessed in-vitro synergy of colistin sparing combinations of fosfomycin (FOS) with meropenem (MEM), tigecycline (TGC) and amikacin (AK) against XDR and PDR Klebsiella pneumoniae ., Method: Non-replicate fully characterised 18 clinical isolates of K. pneumoniae (15 XDR and 3 PDR strains) were subjected to in-vitro synergy testing by checkerboard and time kill assay. Combinations tested were FOS-MEM, FOS-TGC and FOS-AK with glucose-6-phosphate being incorporated in all runs.WGS was carried out on the Illumina next-generation sequencing platform., Results: FOS-MEM and FOS-AK both demonstrated excellent synergy against all PDRs and all but one XDR. Synergy led to lowering of MICs to susceptible breakpoints. FOS-TGC demonstrated antagonism. MLST-231 K. pneumoniae predominated (14), followed by ST-395 (3) and ST147 (1). Majority harboured OXA-232 (n = 15), while n = 2 carried NDM-1 type and n = 1 co-carried NDM-5 + OXA-232. Mortality was high in both ST-231 (57.1%) and ST-395 (66.6%). Synergy was observed despite widespread presence of resistance markers against aminoglycosides [aph(3')-Ic, aacA4, and rmtf], beta-lactams [blaSHV-11, blaTEM-1b, blaCTX-M-15, and blaOXA-232], fosfomycin [fosA6 and fosA5] and presence of porin proteins OmpK37, OmpA and K. pneumoniae antibiotic efflux pumps Kpn F, H, G, and E., Conclusion: FOS + MEM and FOS + AK are excellent colistin sparing combinations against ST 231, ST-395 and ST-147 XDR and PDR K. pneumoniae . FOS with fewer side effects than colistin, excellent tissue distribution and minimal side effects may be recommended in combination with meropenem.

Purpose: Carbapenem inactivation method (CIM) and modified carbapenem inactivation method (mCIM) were recently developed for rapid detection of carbapenemase producing Gram negative bacilli (CP-GNB). In this study we compared the ability of modified Hodge test (MHT), CIM and mCIM to identify CP-GNB in Oman and India., Methods: Fifty fully characterized and genotyped CP-GNB (26 OXA-48-like, 2 NDM-1 from Oman and 22 NDM-1 from India) and 8 AmpC as controls in India were subjected to MHT, CIM, mCIM and mCIM with in-house modifications. Wilcoxon paired test and receiver operating characteristics (ROC) were utilised for statistical analysis., Results: Isolates were predominantly OXA-48-like genes producing Klebsiella pneumoniae from Oman and NDM-1 producing Escherichia coli from India. MHT was positive in all except one OXA-48-like producers and in 70.8 ​% of the NDM-1 isolates. The sensitivity of CIM in detecting 0XA-48 like and NDM-1 carbapenemases were 39.2% and 87.5% respectively. mCIM at 4 ​h detected 92.3 ​% and 79.1% of 0XA-48 and NDM-1 respectively. Using receiver operative characteristics (ROC), highest sensitivity and specificity for detection of OXA-48-like was obtained by mCIM at 4 ​h at cut off 17 ​mm while for NDM-1 CIM was the test of choice at 16 ​mm., Conclusion: CIM and mCIM are simple, cheap and easy tests to perform. CIM gave excellent results with NDM1 strains while it was quite poor in predicting OXA-48-like. We recommend CIM and eCIM for rapid identification of NDM-1 producers and mCIM at 4 ​h and MHT for detection of OXA-48-like. No one method can correctly detect both genotypes. As determined by ROC curves a zone of inhibition of 17 ​mm was considered adequate for detection of OXA-48-like and 16 ​mm of NDM-1 by mCIM at 4 ​h and CIM respectively., (Copyright © 2021 Indian Association of Medical Microbiologists. Published by Elsevier B.V. All rights reserved.)

Human infectious fungal diseases are increasing, despite improved hygienic conditions. We present a case of gastrointestinal basidiobolomycosis (GIB) in a 20-year-old male with a history of progressively worsening abdominal pain. The causative agent was identified as a novel Basidiobolus species. Validation of its novelty was established by analysis of the partial ribosomal operon of two isolates from different organs. Phylogeny of ITS and LSU rRNA showed that these isolates belonged to the genus Basidiobolus, positioned closely to B. heterosporus and B. minor . Morphological and physiological data supported the identity of the species, which was named Basidiobolus omanensis , with CBS 146281 as the holotype. The strains showed high minimum inhibitory concentrations (MICs) to fluconazole (>64 µg/mL), itraconazole and voriconazole (>16 µg/mL), anidulafungin and micafungin (>16 µg/mL), but had a low MIC to amphotericin B (1 µg/mL). The pathogenic role of B. omanensis in gastrointestinal disease is discussed. We highlight the crucial role of molecular identification of these rarely encountered opportunistic fungi.

The COVID-19 pandemic continues to move at record speed. Health systems and hospitals worldwide face unprecedented challenges to effectively prepare and respond to this extraordinary health crisis and anticipated surge. Hospitals should confront these unparalleled challenges with a comprehensive, multidisciplinary, coordinated, and organized strategy. We report our experience with the systematic application of the "4S" principle to guide our institutional preparedness plan for COVID-19. We used an innovative "virtual interdisciplinary COVID-19 team" approach to consolidate our hospital readiness., (The OMJ is Published Bimonthly and Copyrighted 2020 by the OMSB.)

The prevalence of carbapenem-resistant Enterobacterales (CRE) in the Arabian Peninsula is predicted to be high, as suggested from published case reports. Of particular concern, is carbapenem-resistant E. coli (CR-EC), due to the importance of this species as a community pathogen. Herein, we conducted a comprehensive molecular characterization of putative CR-EC strains from Oman. We aim to establish a baseline for future molecular monitoring. We performed whole-genome sequencing (WGS) for 35 putative CR-EC. Isolates were obtained from patients at multiple centers in 2015. Genetic relatedness was investigated using several typing approaches such as MLST, SNP calling, phylogroup and CRISPR typing. Maxiuium likelihood SNP-tree was performed by RAxML after variant calling and removal of recombination regions with Snippy and Gubbins, respectively. Resistance genes, plasmid replicon types, virulence genes, and prophage were also characterised. The online databases CGE, CRISPRcasFinder, Phaster and EnteroBase were used for the in silico analyses. Screening for mutations in genes regulating the expression of porins and efflux pump as well as mutations lead to fluoroquinolones resistance were performed with CLC Genomics Workbench. The genetic diversity suggests a polyclonal population structure with 21 sequence types (ST), of which ST38 being the most prevalent (11%). SNPs analysis revealed possible transmission episodes. Whereas, CRISPR typing helped to spot outlier strains belonged to phylogroups other than B2 which was CRISPR-free. The virulent phylogroups B2 and D were detected in 4 and 9 isolates, respectively. In some strains bacteriophages acted as vectors for virulence genes. Regarding resistance to β-lactam, 22 were carbapenemase producers, 3 carbapenem non-susceptible but carbapenemase-negative, 9 resistant to expanded-spectrum cephalosporins, and one isolate with susceptibility to cephalosporins and carbapenems. Thirteen out of the 22 (59%) carbapenemase-producing isolates were NDM and 7 (23%) were OXA-48-like which mirrors the situation in Indian subcontinent. Two isolates co-produced NDM and OXA-48-like enzymes. In total, 80% (28/35) were CTX-M-15 producers and 23% (8/35) featured AmpC. The high-risk subclones ST131-H30Rx/C2, ST410-H24RxC and ST1193-H64RxC were detected, the latter associated with NDM. To our knowledge, this is the first report of ST1193-H64Rx subclone with NDM. In conclusion, strains showed polyclonal population structure with OXA-48 and NDM as the only carbapenemases in CR-EC from Oman. We detected the high-risk subclone ST131-H30Rx/C2, ST410-H24RxC and ST1193-H64RxC. The latter was reported with carbapenemase gene for the first time here., Competing Interests: The authors have declared that no competing interests exist.

Objectives: A resurgence of pertussis or whooping cough has been observed worldwide despite broad vaccination coverage. Pertussis like illness (PLI) refers to a clinical syndrome compatible with pertussis infection but lacking laboratory confirmation or an epidemiological link to a confirmed case. Our study aimed to estimate the contribution of Bordetella pertussis infection and identifying predictors of its diagnosis in a cohort of children with PLI., Methods: Demographic and clinical information were retrospectively collected from the medical records of children < 13 years old and hospitalized for PLI in two pediatric units in Oman from 1 January 2012 to 31 December 2013. The laboratory data of all cases were reviewed and confirmed cases of pertussis were identified, analyzed, and compared with non-confirmed cases., Results: A total of 131 patients were enrolled in this study. The majority (95.4% [125/131]) were infants. Only 54.1% (71/131) of admitted children with PLI were tested for pertussis. The incidence of pertussis infection among the tested group was 16.9% (12/71) with a 95% confidence interval 8.2-25.6. Severe illness occurred in 56.4% (74/131) of patients, and six were confirmed to have pertussis. Pediatric intensive care unit admission was required for one confirmed case of pertussis and eight cases from the PLI group (three were negative for pertussis, and five were not tested). Receiver operator characteristic curve analysis revealed that a white blood cell count 3 23.5 × 10 9 /L had 96.6% specificity and lymphocytes 3 17 × 10 9 /L had 98.3% specificity., Conclusions: Taking into consideration that the number tested for pertussis was limited, the incidence of pertussis was 16.9% (12 out of 71 patients). Lymphocytosis can be used as a reliable predictor for the diagnosis of pertussis especially in the absence of specific confirmatory tests or until their results are available.

Objectives: Most children presenting with febrile illness require a blood culture to determine the causative organism as well as its sensitivity to antibiotics. However, false-positive results lead to unnecessary hospitalisations, prescriptions and tests. This study aimed to evaluate the impact of false-positive blood cultures among a paediatric population at a tertiary hospital in Oman., Methods: This retrospective study included all 225 children <13 years old with positive blood cultures who presented to the Sultan Qaboos University Hospital, Muscat, Oman, between July 2011 and December 2013. Blood cultures were reviewed to determine whether they were true-positive or contaminated., Results: A total of 344 positive blood cultures were recorded during the study period, of which 185 (53.8%) were true-positive and 159 (46.2%) were contaminated. Most true-positive isolates (26.5%) were coagulase-negative Staphylococcus spp. (CONS) followed by Escherichia coli (9.7%), while the majority of contaminated isolates were CONS (67.9%) followed by Streptococcus spp. (6.9%). Children with contaminated cultures were significantly younger ( P <0.001) while those with true-positive cultures required significantly more frequent hospital admissions, longer hospital stays and more frequent antibiotic prescriptions ( P <0.001 each). Chronic illness and mortality was significantly more frequent among those with true-positive cultures ( P <0.001 and 0.04, respectively). While white blood cell and absolute neutrophil counts were significantly higher in true-positive cultures ( P <0.001 each), there was no significant difference in C-reactive protein (CRP) level ( P = 0.791)., Conclusion: In this population, CRP level was not an adequate marker to differentiate between true- and false-positive cultures. A dedicated well-trained phlebotomy team for paediatric patients is essential., Competing Interests: CONFLICT OF INTEREST The authors declare no conflicts of interest.

Nocardia asteroides is a rare pathogen in peritoneal dialysis-related peritonitis. We report on a 13-year-old female with Nocardia asteroides peritonitis complicated by an intra-abdominal abscess. Linezolid was administered intravenously for 3 months and followed by oral therapy for an additional 5 months with close monitoring for adverse effects. The patient was discharged after 3 months of hospitalization on hemodialysis. The diagnosis and management of such cases can be problematic due to the slow growth and difficulty of identifying Nocardia species. The optimal duration of treatment for Nocardia peritonitis is not known. Linezolid can be used for prolonged periods in cases of trimethoprim/sulfamethoxazole-resistant cases with close monitoring for adverse effects., (Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

Urinary tract infection (UTI) is one of the most common community-acquired infections. Different organisms can be the cause of UTI in children, with resistance to antibiotics becoming a significant problem in the choice of treatment. Worldwide studies have documented the prevalence of uropathogens in different countries. However, there is no previous study documenting the incidence of different uropathogens in Oman. We aim to report the most common uropathogens and their antibiotic sensitivity patterns in children presenting with documented, single episode UTI at a tertiary hospital in Oman. A retrospective analysis of all Omani children below 14 years who presented with a case of first documented UTI to SQUH between September 2008 and August 2012 was conducted. Data were obtained from the patients' electronic records in the hospital information system. Data were then analyzed using SSPS (Statistical Package for Social Sciences program, Version 20, IBM, Chicago, IL, USA). In the retrospective review of all urine cultures, 438 positive urine cultures were identified. Out of those, 208 (47.5%) belonged to children with their first episode of UTI. Thirty-three patients were excluded and 75 patients were included in the final analysis. Escherichia coli was the most frequently encountered uropathogen in our cohort (69%), followed by Klebsiella pneumoniae infection (17%). Nearly half (46.6%) of these two common organism were resistant to Cotrimoxazole, while 31% of them were resistant to Augmentin. Twenty-four percent of the E. coli and K. pneumoniae strains were resistant to Cefuroxime, and only 10% were resistant to nitrofurantoin. Both Augmentin and Cotrimoxazole should not be the first line antibiotics to treat UTI., (Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

Background: Antimicrobial resistance is increasingly recognized as a global challenge. A few studies have emerged on epidemiology of multidrug resistant organisms in tertiary care settings in the Arabian Gulf., Aim: To describe the epidemiology of multi-drug resistant organisms (MDRO) at Sultan Qaboos University Hospital, a tertiary hospital in Oman., Methods: A retrospective review of MDRO records has been conducted throughout the period from January 2012 till December 2012. Organisms were identified and tested by an automated identification and susceptibility system, and the antibiotic susceptibility testing was confirmed by the disk diffusion method., Results: Out of the total of 29,245 admissions, there have been 315 patients registered as MDRO patients giving an overall prevalence rate of 10.8 (95% CI 9.3, 12.4) MDRO cases per 1000 admissions. In addition, the prevalence rate of MDRO isolates was 11.2 (95% CI 9.7, 12.9) per 1000 admissions. Overall, increasing trends in prevalence rates of MDRO patients and MDRO isolates were observed throughout the study period., Conclusion: Antimicrobial resistance is an emerging challenge in Oman. Continuous monitoring of antimicrobial susceptibility and strict adherence to infection prevention guidelines are essential to prevent proliferation of MDRO. Along such quest, stringent antibiotic prescription guidelines are needed in the country.

We report a case of infective endocarditis due to vancomycin-intermediate Staphylococcus aureus (VISA). This was treated with a combination of intravenous linezolid and fusidic acid. Cure was achieved without surgical intervention., (Copyright © 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

A new strain of Influenza A virus, with quadruple segment translocation in its RNA, caused an outbreak of human infection in April 2009 in USA and Mexico. It was classified as Influenza A H1N1 2009. The genetic material originates from three different species: human, avian and swine. By June 2009, the World Health Organization (WHO) had classified this strain as a pandemic virus, making it the first pandemic in 40 years. Influenza A H1N1 2009 is transmitted by respiratory droplets; the transmissibility of this strain is higher than other influenza strains which made infection control difficult. The majority of cases of H1N1 2009 were mild and self limiting, but some people developed complications and others died. Most laboratory tests are insensitive except the polymerase chain reaction (PCR) which is expensive and labour intensive. The Influenza A H1N1 2009 virus is sensitive to neuraminidase inhibitors (oseltamivir and zanamivir), but some isolates resistant to oseltamivir have been reported. A vaccine against the new pandemic strain was available by mid-September 2009 with very good immunogenicity and safety profile. Surveillance is very important at all stages of any pandemic to detect and monitor the trend of viral infections and to prevent the occurrence of future pandemics. The aim of this review is to understand pandemic influenza viruses, and what strategies can be used for surveillance, mitigation and control.

Objectives: Antimicrobial resistance is a growing problem worldwide, which imposes difficulties in the selection of appropriate empirical antimicrobial therapy. This study evaluated extended-spectrum β-lactamase (ESBL) isolates in 2005 in The Department of Child Health at Sultan Qaboos University Hospital (SQUH), Oman., Methods: During the 12 month period from January 2005 to December 2005, ESBL isolates from paediatrics inpatients were identified and analysed. Risk factors for the patients who grew ESBLs were analysed., Results: 13.3% of E. coli and 16.6% of Klebsiella pneumoniae isolated were ESBL producers. Most of the ESBLs were from urine (46.2%) and blood (42.6%). The main risk factors for ESBL in these children were previous exposure to antimicrobials (100%), prolonged hospital stay, severe illness (92.3%) and female gender (84.6%). Sensitivity of 100% was observed to carbapenems whereas 92% of the isolates were susceptible to amikacin. The oximino-cephalosporins were 100% resistant. Klebsiella pneumoniae were 100% resistant to piperacillin-tazobactam and nitrofurantoin. E. coli was 100% resistant to trimethoprim-sulfamethoxazole and ciprofloxacin. No resistance was recorded for the following combinations: amikacin plus piperacillin-tazobactam, amikacin plus nitrofurantoin and gentamicin plus nitrofurantoin., Conclusion: ESBL-producing organisms are becoming a major problem in Omani children. Exposure to antimicrobials and long admissions are modifiable risk factors that should be targeted for better control. Carbapenems are the most sensitive and reliable treatment options for infections caused by ESBLs. Amikacin plus piperacillin-tazobactam or nitrofurantoin are good alternatives.

Background: extended spectrum β-lactamase (ESBL) producing gram negative bacilli are becoming a growing problem worldwide with difficulties in designing a national formulary for empirical treatment of gram negative sepsis., Objectives: In this study, we investigated the in vitro activity of Carbapenems, Pipracillin-Tazobactam, Ciprofloxacin alone or in combination with aminoglycosides against ESBL-producing strains isolated from clinical samples., Methods: Three hundred and one ESBL-producing Escherichia coli and K. pneumoniae strains isolated from clinical samples were investigated. Isolates were screened initially for ESBL production using an automated system. All ESBL isolates were further confirmed using the double-disk diffusion method., Results: The overall Piperacillin-Tazobactam susceptibility was 57.9 (64.4% E. coli and 43.6% Klebsiella pneumoniae). Only 29.6% of ESBLs (24.9% E. coli and 39.6% Klebsiella pneumoniae) were ciprofloxacin susceptible. 98.1% E. coli and 93.1% of Klebsiella pneumoniae were susceptible to Piperacillin-Tazobactam plus Amikacin combination. 73.7% E. coli and 61.4% of Klebsiella pneumoniae were susceptible to Piperacillin-Tazobactam plus Gentamicin combination. 96.7% E. coli and 91.1% of Klebsiella pneumoniae were susceptible to Ciprofloxacin plus Amikacin combination. 41.2% E. coli and 51.5% of Klebsiella pneumoniae were susceptible to Ciprofloxacin plus Gentamicin combination., Conclusion: ESBLs have high resistance profile against Piperacillin/Tazobactam and Ciprofloxacin. The ESBLs from Oman have similar resistantce pattern as those reported from UK and USA. This resistance decreases when these drugs are combined with Amikacin. All ESBLs are susceptible to Carbapenems. However, carbepenam overuse can lead to emergence of carbapenems resistant gram negative bacilli and ESBLs. Combination of Amikacin plus Piperacillin/Tazobactam is a feasible empirical therapy for ESBLs.

Objective: To evaluate the prevalence of extended-spectrum beta-lactamases isolates over one year period at Sultan Qaboos University Hospital., Methods: We identified the ESBL isolates during a 12-month period from July 2004 to June 2005, using a commercial system, and confirmed the result using the National Committee for Clinical Laboratory Standards-approved double-disk diffusion method., Results: Sensitivity was recorded for a wide range of antibiotics, aminoglycosides, carbapenem, cephalosporins, quinolones, aztreonam, ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin-tazobactam, trimethoprim/ sulfamethoxazole and nitrofurantoin. Of the total ESBL isolated, 29.6% were from medical ward, followed by outpatients clinic, 24.3%. Urine was the main source of ESBLs 70.4%, followed by 16.5% from blood. We observed a 100% sensitivity to carbapenems, whereas 93.9% of the isolates were susceptible to amikacin. Cephalosporins were 100% resistant, except for cefoxitin, which demonstrated sensitivity of 77.4%. Aztreonam, ampicillin, co-amoxyclav and ampicillin/sulbactam were 100% resistant. Of the isolates, 57.4% were sensitive to nitrofurantoin, whereas Tazocin showed 49.6% sensitivity and co-trimoxazole 13.9%. To quinolones, 74.8% of the isolates were resistant., Conclusion: Excess use of third generation cephalosporins led to increase rate of ESBLs, which are difficult to treat. Carbapenem are most reliable for treatment of infections caused by ESBL isolates. However, overuse of carbapenem may lead to resistance of other gram-negative organisms. Therefore, justifiable use of third-generation cephalosporins, will be an effective means of controlling and decreasing the spread of ESBL isolates.