The Role of Interproximal Reduction (IPR) in Clear Aligner Therapy: A Critical Analysis of Indications, Techniques, and Outcomes.

Interproximal reduction (IPR) has become a standard practice in orthodontic treatment, particularly in the clear aligner therapy. It became an integral part of the digital plan when using clear aligners. Given the irreversible nature of IPR, precise planning and performance is essential. This article aims to analyze and summarize the existing literature on IPR in the context of clear aligners. The goal is to help clinicians to gain essential knowledge for safely and effectively navigating IPR. The review critically examines different perspectives found in the literature, covering indications, methods, and outcomes. Topics exploring the impact of IPR on treatment outcomes include space gaining, addressing tooth size discrepancies, tooth shape adjustments, resolving malocclusion, and enhancing aesthetics. Emphasizing precision of the procedure by the clinician and awareness of contraindications, the article also discusses the impact of IPR on patients. This includes considerations like increased pulp temperature, susceptibility to cavities due to changes in enamel roughness, effects on soft tissues, and post-IPR tooth sensitivity.

Delays in presentation, diagnosis, and treatment in Sudanese women with breast cancer: a cross-sectional study.

BACKGROUND: The poor prognosis of breast cancer in Sudan could be due to delayed treatment and diagnosis at an advanced stage. Our study aimed to assess the extent of delays from onset of symptoms to treatment in Sudanese women with breast cancer, as well as identify factors contributing to these delays. MATERIALS AND METHODS: We conducted a multi-center cross sectional study between March and April 2023. Data were collected from the medical records and interviews with women with breast cancer in the two main oncology centers in Sudan. Linear regression was used to identify the predictors of delayed presentation. RESULTS: We interviewed 601 women with breast cancer. The majority of women (50.1%) were diagnosed at locally advanced or metastatic disease. The median interval from the onset of symptoms to receiving oncologic treatment was 221 days (IQR = 92, 496). The longest delay was the presentation delay 61 (31 244) days. The median duration for diagnosis delay and treatment delay was 21 (10.57) days and 27 (10.64) days, respectively. Predictors of early presentation included, being young (ß = -5.3; 95% CI = 0.06 to 10), married (ß = -264; 95% CI = -427 to -101), divorced (ß = -306; 95% CI = -549 to -63), or widowed (ß = -320; 95% CI = --543 to -97), urban residence (ß = -107; 95% CI = -213 to -2.3), and seeking traditional healer (ß = -204; 95% CI = -383 to -26). CONCLUSION: Most Sudanese women with breast cancer experience significant patient delays, often presenting at advanced stages. Factors like being single, older, and living in rural areas contribute to these delays. Increasing breast cancer education, improving healthcare access and addressing sociodemographic barriers can potentially expedite diagnosis and improve outcomes.

Retraction: Xanthogranulomatous Cholecystitis: A Rare Variant of Chronic Cholecystitis.

[This retracts the article DOI: 10.7759/cureus.21400.].

Maternal Awareness of Vitamin D Deficiency in Infants and Children Up to the Age of 6 Years: A Cross-sectional Study in Jordan.

Vitamin D deficiency is a worldwide health problem. The current study aims to evaluate mothers' habits and knowledge regarding vitamin D deficiency in kids up to the age of 6. A questionnaire was made available online among mothers of children between 0 and 6 years. Most mothers (65.7%) were aged between 30 and 40 years. Sunlight was identified as the main source of vitamin D by most participants (89.1%), while fish and eggs were reported to be the main dietary sources of vitamin D by most participants (63.7% and 65.2%, respectively). Most participants identified the benefits of vitamin D, risk factors, and complications of vitamin D deficiency. The majority (86.4%) think they need more information on vitamin D deficiency in children. A moderate knowledge level was reported among more than half of the participants although there was inadequate knowledge in certain domains of vitamin D knowledge. More education is required for mothers about vitamin D deficiency.

Conservative Management of Dentigerous Cysts Associated With Mixed Dentition: A Retrospective Cohort Study.

Objectives The pediatric dentigerous cysts might vary by region and population group. Large cystic lesions are typically treated with marsupialization before enucleation in order to decompress the lesion and reduce its volume; however, in pediatric cystic lesions, conservative marsupialization and decompression can be used to manage the condition without additional enucleation. The current study's objectives were to present a case series of pediatric dentigerous cysts and discuss the conservative management of these cystic lesions associated with mixed dentition. Methods A retrospective cohort analysis of patients diagnosed with cystic lesions between 2016 and 2023 was identified. Data on clinical, radiological, pathological, and odontogenic causes were collected. The marsupialization approach was performed in all cases. Patient demographic information was also examined, and a literature review was carried out to identify comparable cases. Results Sixteen young patients were diagnosed with dentigerous cysts, and this was confirmed by clinical, radiological, and pathological examinations. Females comprised 56.2% of the cases, with the right side predominating (62.5%). Deciduous teeth related to the lesion could be extracted normally in all cases. All associated permanent teeth erupted rapidly after the intervention. Conclusion The marsupialization technique used in the current cases of dentigerous cysts associated with mixed dentition was highly successful, and all permanent impacted teeth erupted without any cystic recurrence.

Association Between Authentic Leadership in Nurse Managers and Performance and Intention to Leave Among Registered Nurses.

BACKGROUND: Authentic leadership in nurse managers has been identified as a strong predictor of multiple nurse outcomes. However, its association with staff performance and nurses' intention to leave has yet to be established. PURPOSE: This study was designed to identify the predictive effect of sociodemographic variables on nurse performance and intention to leave and to examine the relationship between authentic leadership in nurse managers and, respectively, nurse performance and intention to leave. METHODS: A comparative and correlational design and a cross-sectional survey approach were used. A convenience sample of 166 registered nurses working in a government hospital in Jordan was recruited. Data collection was performed online using the sociodemographics questionnaire, the Authentic Leadership Questionnaire, the Turnover Intention Scale, and the Six Dimensions of Nurse's Performance Scale. Data were analyzed using descriptive statistics, independent t test, one-way analysis of variance, Pearson correlation, and multiple hierarchical linear regression. RESULTS: The overall mean score was 2.08 (SD = 0.87) for the Authentic Leadership Questionnaire, 3.57 (SD = 1.76) for the Turnover Intention Scale, and 3.00 (SD = 0.51) for the Staff Performance Scale. Mean nursing performance differed significantly based on marital status, whereas intention to leave differed significantly based on marital status and the respondent's perception of their first-line manager. A statistically significant, positive correlation between authentic leadership and staff performance and a statistically significant, negative correlation between authentic leadership and intention to leave were found. In addition, authentic leadership was uniquely associated with staff performance (B = 0.19, p < .05) and intention to leave (B = -0.39, p < .05) in the hierarchical regression analysis after controlling for sociodemographic variables. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Authentic leadership from nurse managers is associated with improved nurse performance and lower nurse intention to leave. Nurse managers may enhance authentic leadership attributes to better retain nurses in hospitals and improve nurse job performance.

Mental health of health professionals and their perspectives on mental health services in a conflict-affected setting: a qualitative study in health centres in the Gaza Strip during the COVID-19 pandemic.

OBJECTIVES: To explore how primary care health professionals perceive their own mental health in a conflict-affected setting during and beyond the COVID-19 pandemic and to explore their perspectives on mental health services. METHODS: The Gaza Strip faces a chronic humanitarian crisis and is suffering from the consequences of the COVID-19 pandemic; United Nations Relief and Works Agency (UNRWA) health centres were used to recruit participants for this study. Semistructured interviews were conducted with 29 health professionals in UNRWA health centres who were sampled using maximum variation sampling. Transcripts were translated, double checked and analysed via thematic analysis. RESULTS: From the analysis, a thematic map was developed showing how health professionals perceive their mental health impacts. This included difficulties due to the COVID-19 pandemic, as well as the socioeconomic processes stemming from the on-going conflict.Another thematic map was developed showing the perceived strengths and challenges of the health services. The strengths included positive impact of the services to the service users and health professionals. In terms of challenges, health professionals identified socioeconomic processes and aspects of remote service provision during COVID-19. CONCLUSIONS: Based on the findings, we suggest that an improved signposting mechanism should be developed to address many of the challenges that emergencies bring about; in particular, this could support the health professionals' mental health, as well as improve the response to patients' socioeconomic challenges. We further suggest recommendations for improving mental health services when delivered remotely to increase their resiliency during various emergencies.

Design, synthesis, and performance evaluation of TiO2-dye sensitized solar cells using 2,2'-bithiophene-based co-sensitizers.

We report on the synthesis and characterization of six novel 2,2'-bithiophene-based organic compounds (3a-c and 5a-c) that are designed to serve as co-sensitizers for dye-sensitized solar cells (DSSCs) based on TiO2. The compounds are linked to various donor and acceptor groups, and we confirm their chemical structures through spectral analyses. Our focus is on enhancing the performance of metal based N3, and the compounds were designed to operate at the nanoscale. We performed absorption and fluorescence emission measurements in dimethylformamide (DMF), where one of our compounds 5a exhibited the longest maximum absorption and maximum emission wavelengths, indicating the significant impact of the para methoxy group as a strong electron-donating group. Our dyes 5a + N3 (η = 7.42%) and 5c + N3 (η = 6.57%) outperformed N3 (η = 6.16%) alone, where the values of short current density (JSC) and open circuit voltage (VOC) for these two systems also improved. We also investigated the charge transfer resistance at the TiO2/dye/electrolyte interface using electrochemical impedance spectroscopy (EIS), which is important in the context of nanotechnology. According to the Nyquist plot, the 5a + N3 cocktail exhibited the lowest recombination rate, resulting in the highest VOC. Our theoretical calculations based on density functional theory (DFT) are also in agreement with the experimental process. These findings suggest that our compounds have great potential as efficient DSSC co-sensitizers. This study provides valuable insights into the design and synthesis of new organic compounds for use as co-sensitizers in DSSCs based on TiO2 and highlights the potential of these compounds for use in efficient solar energy conversion.

Vitamin D deficiency and risk of recurrent aphthous stomatitis: updated meta-analysis with trial sequential analysis.

Background: Growing evidence suggests a significant association between vitamin D deficiency and RAS. Hence, the present meta-analysis and trial sequential analysis sought to investigate the potential association between low serum vitamin D levels and RAS. Methods: PubMed, Scopus, Embase, and Web of Science were comprehensively searched on December 1st, 2022 to retrieve all relevant studies. The grey literature was also searched via ProQuest. All case-control studies on the association between vitamin D and RAS were considered. The quality appraisal of the included studies was done using Newcastle-Ottawa scale. RevMan 5.0 and trial sequential analysis (TSA) programs were used for analyses. Results: A total of 14 case-control studies with 1468 subjects (721 RAS patients and 747 controls) were included. The pooled data revealed a significant association between low serum levels of vitamin D and the risk of RAS (mean difference = - 8.73, 95% CI: - 12.02 to - 5.44, I2 = 94%, P < 0.00001). Additionally, TSA findings indicated that the current studies surpassed the required information size, confirming that the differences were reliable. Conclusion: The available evidence suggests that Vitamin D deficiency may have a role in the pathogenesis of RAS. Therefore, evaluation of vitamin D should be considered in RAS patients. Additionally, the results support the possibility of using vitamin D supplements in the management of RAS patients with inadequate serum levels of vitamin D. Future interventional studies are required to evaluate the benefits of vitamin D replacement in prevention and treatment of RAS.

Comprehensive genetic analyses of childhood acute leukemia in Iraq using next-generation sequencing.

Background: Molecular analyses in hematological malignancies provide insights about genetic makeup. Probable etiological factors in leukemogenesis could also be disclosed. Since genetic analyses are still primitive in Iraq, a country of repeated wars, we conceived of performing next-generation sequencing (NGS), to disclose the genomic landscape of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) among a cohort of Iraqi children. Methods: Dried blood samples were collected from Iraqi children with ALL (n=55), or AML (n=11), and transferred to Japan where NGS was done. Whole-exome, whole-genome, and targeted gene sequencings were performed. Results: Somatic point mutations and the copy number variations among Iraqi children with acute leukemia were comparable with those in other countries, and cytosine-to-thymine nucleotide alterations were dominant. Strikingly, TCF3-PBX1 was the most recurrent fusion gene (22.4%) in B-cell precursor ALL (B-ALL), and acute promyelocytic leukemia (AML-M3) was subtyped in 5 AML cases. Additionally, a high frequency of RAS signaling pathway mutations was detected in children with B-ALL (38.8%), along with 3 AML cases that carried oncogenic RAS. Conclusions: Apart from disclosing the high frequency of TCF3-PBX1, NGS confirmed our previous finding of recurrent RAS mutations in Iraqi childhood acute leukemia. Our results suggest that the biology of Iraqi childhood acute leukemia is in part characteristic, where the war-aftermath environment or geography might play a role.

Systemic sclerosis associated with primary sclerosing cholangitis and hyperthyroidism: a case report.

The association between systemic sclerosis and other immune-mediated diseases such as primary sclerosing cholangitis and hyperthyroidism should be suspected in case the patient presents with similar symptoms. A 43-year-old woman presented to the hospital with progressive jaundice, dark urine, dyspnoea, fatigue, generalized arthralgia, weight loss, and amenorrhoea. In addition, she was diagnosed with systemic sclerosis seven years ago. The patient was diagnosed recently with primary sclerosing cholangitis and hyperthyroidism through laboratory tests and investigations such as magnetic resonance cholangiopancreatography, ultrasound, and computed tomography scan. After appropriate treatment and follow-up, the patient recovered well. Immune-mediated diseases can occur simultaneously or consequently due to the common immunological dysfunction that causes these conditions.

Synthesis of efficient bi-anchoring bifuran/biphenyl derivatives for dye-sensitized solar cell applications.

The synthesis, description, and demonstration of dye-sensitive solar cell sensitizers containing bifuran/biphenyl derivatives with cyanoacetic acid, barbiturate, thiobarbituric acid, and 4-carboxylcyanoacetamides have been reported. A photovoltaic performance measurement was conducted using the Ru(ii) dye N3 as a reference to examine the effects of different electron acceptor units and replacement of the π-spacer bifuran by biphenyl units on the photophysical, electrochemical, and photovoltaic properties of eight new distinct organic dyes HB-1-8. The new organic dyes HB-1-8 were prepared and compared with the N3 metal dye. Density functional theory calculations were carried out to explore the ground state geometrical structures and electronic structures of the eight dyes. Under standard global AM 1.5 solar condition, the solar cells based on HB-1-8 show the overall power conversion efficiencies of 2.93-5.51%. The presented research shows that the organic dye photovoltaic performances can vary greatly depending on the type of electron donor and acceptor used. Dye HB-3 exhibited the highest efficiency among the eight investigated dyes, reaching 5.51% with a V OC value higher than N3.

A rare case of an intra-articular true lipoma of the ankle.

BACKGROUND: Most of the foot and ankle soft tissue tumors are benign. Although lipomas are the most common soft tissue tumors, intra-articular lipomas are an extremely rare entity. The majority of described cases of intra-articular lipomas occur in the knee joint. In particular, an intra-articular true lipoma of the ankle has not been reported. CASE PRESENTATION: We report the case of a 45-year-old woman who presented with a progressively growing ankle mass over 5 years, which started to restrict the range of motion. It was not preceded by any trauma or sports activity. On examination, a non-tender firm mass was evident on the lateral aspect of the right ankle joint with no signs of inflammation. It was non-compressible, non-mobile, and did not transilluminate. The clinical diagnosis was probable for a soft tissue ganglion. A radiograph revealed a soft tissue opacity over the anterolateral aspect of the tibiotalar joint. Magnetic resonance imaging (MRI) demonstrated a well-defined, multilobulated, encapsulated lesion located at the lateral aspect of the tibiotalar joint; with intra- and extra-articular components and an analogous signal intensity to fat. The patient underwent surgical excision of the tumor, and the histopathological examination showed mature adipose tissue representing an intra-articular lipoma. At the follow-up visit, the patient had complete resolution of symptoms and no active complaints. CONCLUSION: An intra-articular true lipoma of the ankle is an extremely rare tumor. MRI is an invaluable diagnostic tool to make a reliable diagnosis of intra-articular masses.

Mycetoma management and clinical outcomes: the Mycetoma Research Center experience.

BACKGROUND: Mycetoma is a chronic granulomatous inflammatory disease that affects the cutaneous and subcutaneous tissues, leading to gruesome complications if not treated early. As a neglected disease, it has received scant attention in developing curable drugs. Mycetoma treatment is still based on expert opinions in the absence of guidelines. METHODS: This descriptive, cross-sectional, hospital-based study aimed to determine and assess the disease treatment outcomes observed at Mycetoma Research Center, Sudan. RESULTS: In this study, 75% of patients had eumycetoma, all of whom were treated with itraconazole and 37.4% underwent surgical excision, while 25% of the patients had actinomycetoma, 99.2% of whom were treated with a combination of cotrimoxazole and amoxicillin-clavulanate. The cure rate was 12.7% and 14.3% for patients with eumycetoma and actinomycetoma, respectively. Only 6.1% of eumycetoma patients underwent amputation. Remarkably, no patient with actinomycetoma underwent an amputation. Small lesions (OR=10.09, p<0.001) and good follow-up (OR=6.81, p=0.002) were positive predictors of complete cure. In terms of amputation, history of surgical recurrence at presentation (OR=3.67, p=0.020) and presence of grains (OR=7.13, p=0.012) were positive predictors, whereas small lesions were negative predictors (OR=0.06, p=0.009). CONCLUSIONS: Treatment of mycetoma was suboptimal, with a low cure rate despite a long treatment duration. Complete cure has a significant association with small lesions and good follow-up.

Increasing Prevalence of Methicillin-resistant Staphylococcus aureus among Hospital and Community acquired Infections in Khartoum State, Sudan.

BACKGROUND: Staphylococcus aureus is an important bacterium that can cause many diseases. Methicillin-resistant S.aureus (MRSA) is often sub-categorized as Hospital or Community acquired infection. MRSA causes serious problems, such as bloodstream and surgical site infections or pneumonia. OBJECTIVES: The present study aimed to identify S. aureus by 16SrRNA using PCR, estimate the antibiotic susceptibility pattern and determine the prevalence of MRSA among Hospital and community acquired infections. METHODS: A cross-sectional laboratory-based study was conducted during the period from November 2020 to January 2021. Conventional methods were used to identify S. aureus and isolate confirmation was performed by PCR targeting 16SrRNA gene. All isolated organisms were tested for their in-vitro antimicrobial susceptibility. RESULT: Among the enrolled patients (n, 300), MRSA was observed in 185 (61.7%). The highest frequency was shown in the age group over 45 years old (46.7%). The result also showed a high frequency of S. aureus among community infections (81.7%), MRSA in hospital acquired infections was 10.7% while 51% was community acquired. The antimicrobial susceptibilities against MRSA isolates showed high sensitivity to Ceftriaxone 90.0%). Most infections caused by MRSA isolates were respiratory tract infection (RTI) (28.3%) and Septicemia (22.5%). CONCLUSION: The present study highlighted a high proportion of MRSA in clinical settings at Khartoum State. Antibiotic susceptibility results showed that Ceftriaxone was the drug of choice against MRSA isolates. Overuse and misuse of antibiotics, along with self-medication, seem to be the cause of antibiotic resistance, thus should be avoided.

Role of Polymers in Microfluidic Devices.

Polymers are sustainable and renewable materials that are in high demand due to their excellent properties. Natural and synthetic polymers with high flexibility, good biocompatibility, good degradation rate, and stiffness are widely used for various applications, such as tissue engineering, drug delivery, and microfluidic chip fabrication. Indeed, recent advances in microfluidic technology allow the fabrication of polymeric matrix to construct microfluidic scaffolds for tissue engineering and to set up a well-controlled microenvironment for manipulating fluids and particles. In this review, polymers as materials for the fabrication of microfluidic chips have been highlighted. Successful models exploiting polymers in microfluidic devices to generate uniform particles as drug vehicles or artificial cells have been also discussed. Additionally, using polymers as bioink for 3D printing or as a matrix to functionalize the sensing surface in microfluidic devices has also been mentioned. The rapid progress made in the combination of polymers and microfluidics presents a low-cost, reproducible, and scalable approach for a promising future in the manufacturing of biomimetic scaffolds for tissue engineering.

The Spike Protein of SARS-coV2 19B (S) Clade Mirrors Critical Features of Viral Adaptation and Coevolution.

Pathogens including viruses evolve in tandem with diversity in their animal and human hosts. For SARS-coV2, the focus is generally for understanding such coevolution on the virus spike protein, since it demonstrates high mutation rates compared to other genome regions, particularly in the receptor-binding domain (RBD). Viral sequences of the SARS-coV2 19B (S) clade and variants of concern from different continents were investigated, with a focus on the A.29 lineage, which presented with different mutational patterns within the 19B (S) lineages in order to learn more about how SARS-coV2 may have evolved and adapted to widely diverse populations globally. Results indicated that SARS-coV2 went through evolutionary constrains and intense selective pressure, particularly in Africa. This was manifested in a departure from neutrality with excess nonsynonymous mutations and a negative Tajima D consistent with rapid expansion and directional selection as well as deletion and deletion-frameshifts in the N-terminal domain (NTD region) of the spike protein. In conclusion, we hypothesize that viral transmission during epidemics through populations of diverse genomic structures and marked complexity may be a significant factor for the virus to acquire distinct patterns of mutations within these populations in order to ensure its survival and fitness, explaining the emergence of novel variants and strains.

High-level visual search in children with autism.

Visual search has been classified as easy feature search, with rapid target detection and little set size dependence, versus slower difficult search with focused attention, with set size-dependent speed. Reverse hierarchy theory attributes these classes to rapid high cortical-level vision at a glance versus low-level vision with scrutiny, attributing easy search to high-level representations. Accordingly, faces "pop out" of heterogeneous object photographs. Individuals with autism have difficulties recognizing faces, and we now asked if this disability disturbs their search for faces. We compare search times and set size slopes for children with autism spectrum disorders (ASDs) and those with neurotypical development (NT) when searching for faces. Human face targets were found rapidly, with shallow set size slopes. The between-group difference between slopes (18.8 vs. 11.3 ms/item) is significant, suggesting that faces may not "pop out" as easily, but in our view does not warrant classifying ASD face search as categorically different from that of NT children. We also tested search for different target categories, dog and lion faces, and nonface basic categories, cars and houses. The ASD group was generally a bit slower than the NT group, and their slopes were somewhat steeper. Nevertheless, the overall dependencies on target category were similar: human face search fastest, nonface categories slowest, and dog and lion faces in between. We conclude that autism may spare vision at a glance, including face detection, despite its reported effects on face recognition, which may require vision with scrutiny. This dichotomy is consistent with the two perceptual modes suggested by reverse hierarchy theory.

Synthesis of innovative triphenylamine-functionalized organic photosensitizers outperformed the benchmark dye N719 for high-efficiency dye-sensitized solar cells.

Herein, we present a thorough photovoltaic investigation of four triphenylamine organic sensitizers with D-π-A configurations and compare their photovoltaic performances to the conventional ruthenium-based sensitizer N719. SFA-5-8 are synthesized and utilized as sensitizers for dye-sensitized solar cell (DSSC) applications. The effects of the donor unit (triphenylamine), π-conjugation bridge (thiophene ring), and various acceptors (phenylacetonitrile and 2-cyanoacetamide derivatives) were investigated. Moreover, this was asserted by profound calculations of HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, the molecular electrostatic potential (MEP), and natural bond orbital (NBO) that had been studied for the TPA-sensitizers. Theoretical density functional theory (DFT) was performed to study the distribution of electron density between donor and acceptor moieties. The sensitization by the absorption of sensitizers SFA-5-8 leads to an obvious enhancement in the visible light absorption (300-750 nm) as well as a higher photovoltaic efficiency in the range of (5.53-7.56%). Under optimized conditions, SFA-7 showed outstanding sensitization of nanocrystalline TiO2, resulting in enhancing the visible light absorption and upgrading the power conversion efficiency (PCE) to approximately 7.56% over that reported for the N719 (7.29%). Remarkably, SFA-7 outperformed N719 by 4% in the total conversion efficiency. Significantly, the superior performance of SFA-7 could be mainly ascribed to the higher short-circuit photocurrents (Jsc) in parallel with larger open-circuit voltages (Voc) and more importantly, the presence of different anchoring moieties that could enhance the ability to fill the gaps on the surface of the TiO2 semiconductor. That could be largely reflected in the overall enhancement in the device efficiency. Moreover, the theoretical electronic and photovoltaic properties of all studied sensitizers have been compared with experimental results. All the 2-cyanoacrylamide derivative sensitizers demonstrated robust photovoltaic performance.

Molecular analysis for the OprD gene among Pseudomonas aueroginosa clinical isolates obtained from hospitals in Jordan.

INTRODUCTION: Pseudomonas aeruginosa has increasingly been associated with the emergence of antibiotic resistance. Antibiotic resistance among P. aeruginosa isolates is an ambiguous and complicated mechanism utilizing several enzymes and structural proteins. This study was conducted to investigate the prevalence of mutations in the chromosomal OprD gene that show resistance to carbapenems among clinical isolates of P. aeruginosa. METHODOLOGY: Sixty-three clinical isolates of P. aeruginosa resistant to meropenem were collected from public hospitals in Irbid city, north of Jordan. Analysis of antimicrobial susceptibility was carried out and their susceptibility was categorized. Molecular analysis of mutations in the OprD gene was performed using restriction fragment length polymorphism (RFLP) and DNA sequencing. RESULTS: Molecular analysis of P. aeruginosa isolates showed 52% of the common molecular modifications among the collected isolates. These alterations could be associated and affect meropenem-susceptibility rather than imipenem. The most frequent molecular changes among the resistant isolates were the F170L substitution mutation. This was detected in 22 (35%) of the isolates with an unusual insertion sequence (IS) of 100 bp within the 590 bp DNA segment downstream of the restriction site. The divergent sequence of 10 amino acids 372(VDSSSSYAGL)383 was detected in 7 (11%) of the isolates. CONCLUSIONS: A significant alteration in the OprD gene in P. aeruginosa clinical isolates was found. Alterations in the OprD gene could be linked to protein permeability of the outer membrane of P. aeruginosa associated with meropenem resistance. Further investigations with a larger number of bacterial isolates are needed to validate the proposed association.