Antimicrobial management of dental infections: Updated review.

Dental infections, which include anything from severe periodontal illnesses and abscess forms to routine tooth caries, are a major public health risk. This review article focuses on the pathophysiology and treatment of dental infections. A narrative review was conducted based on several published articles, relevant journals, and books in Google Scholar PubMed using the keywords dental caries, periodontal disease, gingivitis, and related diseases; we excluded duplicated information. Our review illustrated the types of dental infections and the proper antimicrobial drug that is suitable for this disease. Drawing from recent research findings and clinical evidence, we explore the spectrum of bacteria commonly associated with dental infections and their susceptibility profiles to various antibiotics. Emphasis is placed on understanding the mechanisms of antibiotic action and resistance in the context of dental pathogens, shedding light on optimal treatment regimens and potential challenges in clinical management. Additionally, we go over the clinical consequences of antibiotic therapy in dentistry, taking into account factors like patient selection, dose guidelines, and side effects. The management of dental infections through antimicrobial strategies has undergone significant advancements, as evidenced by this updated review. Besides the normal methods, emerging technologies such as 3D printing for drug delivery of antibiotics and disinfectants hold promise in enhancing treatment efficacy and patient outcomes. By leveraging the precision and customization afforded by 3D printing, dentistry can tailor antimicrobial interventions to individual patient needs, optimizing therapeutic outcomes while minimizing adverse effects.

Comparisons of lumbosacral kinematics among non-specific chronic low back pain subgroups and healthy during prolonged sitting: A cross-sectional observational study.

BACKGROUND: The literature has suggested a variety of postural changes of the spine that possibly contribute to the increase in back pain during sitting in persons with non-specific chronic low back pain (NS-CLBP). However, the heterogeneity of NS-CLBP persons has made the ability to attribute pain increase to a particular sitting posture very difficult. Therefore, the purpose of this study was to compare lumbosacral kinematics and their roles in pain increase among homogenous NS-CLBP subgroups and healthy controls over a 1-h sitting period. METHODS: Twenty NS-CLBP subjects with motor control impairment [10 classified as having flexion pattern (FP) disorder, and 10 with active extension pattern (AEP) disorder], and 10 healthy controls participated in the study. Subjects underwent a 1-h sitting protocol on a standard office chair. Lumbosacral postures including sacral tilt, third lumbar vertebrae (L3) position, and relative lower lumbar angle were recorded using two-dimensional inclinometers over the 1-h period. Perceived back-pain intensity was measured using a visual analog scale every 10 min throughout the sitting period. RESULTS: All study groups (FP, AEP and healthy controls) significantly differed from each other in the measured lumbosacral kinematics at the beginning as well as at the end of the sitting period (p ≤ 0.05). Only the NS-CLBP subgroups showed significant changes in the lumbosacral kinematics across the 1-h sitting period (p < 0.01), and that the directions of change occurred toward end spinal postures (lumbar kyphosis for FP subgroup and lumbar lordosis for the AEP subgroup). In addition, both NS-CLBP subgroups reported a similarly significant increase in pain through mid-sitting (p < 0.001). However, after mid-sitting, the AEP subgroup reported much less increase in pain level that was accompanied by a significant decrease in the lumbar lordotic postures (p = 0.001) compared to FP subgroup. CONCLUSION: The present study's findings suggest that each NS-CLBP subgroup presented with differently inherent sitting postures. These inherently dysfunctional postures coupled with the directional changes in the lumbosacral kinematics toward the extreme ranges across the 1-h sitting period, might explain the significant increase in pain among subgroups.

Clinical Pharmacogenetics of Angiotensin II Receptor Blockers in Iraq.

Background: Clinical pharmacogenetics is a rapidly growing field that focuses on the study of genetic variations and their impact on drug metabolism, efficacy, and safety. Angiotensin II receptor blockers (ARBs) are commonly used to treat hypertension in Iraq but not all patients respond equally to these drugs. Aim: This article aims to review the current evidence on the clinical pharmacogenetics of ARBs in Iraq and its implications for personalized medicine. Materials and Methods: We conducted a literature review of studies on the genetic variations that affect the response to ARBs in Iraq. We also reviewed the prevalence of these genetic variants in the Iraqi population and discussed the potential clinical implications for personalized medicine. Results: The most studied genetic variations associated with ARB response in Iraq are the angiotensin-converting enzyme gene insertion/deletion polymorphism and the angiotensin II type 1 receptor gene A1166C polymorphism. The angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with variability in response to ARBs, while the angiotensin II type 1 receptor A1166C polymorphism is associated with an increased risk of cardiovascular events in patients treated with ARBs. The prevalence of these genetic variants in the Iraqi population varies widely depending on the region and ethnic group. Conclusion: The clinical pharmacogenetics of ARBs in Iraq suggests that pharmacogenetic testing could improve the selection and dosing of ARBs in Iraqi patients, leading to better patient outcomes and cost-effective healthcare.

Fe3O4 supported [Cu(ii)(met)(pro-H)2] complex as a novel nanomagnetic catalytic system for room temperature C-O coupling reactions.

In this study, a newly-designed copper(ii) complex of metformin and l-proline which was immobilized on Fe3O4 MNPs was developed. The structure of the catalyst platform was fully characterized using spectroscopic analyses. Moreover, the catalytic activity of [Fe3O4@Cu(ii)(Met)(Pro-H)2] was investigated in a one-pot synthesis of a variety of functionalized ethers in reasonable to excellent yields through Ullman reaction in an aqueous environment using various aryl halides, phenol, and Cs2CO3 and without using any external Cu-reducing agents. Notably, gentle catalytic conditions, quick reaction times, applicability, low cost, and preventing dangerous chemicals and solvents during synthesis and catalytic application are some of the superior properties of the [Fe3O4@Cu(ii)(Met)(Pro-H)2] complex. Furthermore, the catalyst can be reused for several runs (at least eight times) without remarkable loss in efficiency.

Longitudinal clinical study of patients with iron rim lesions in multiple sclerosis.

BACKGROUND: Iron rims (IRs) surrounding white matter lesions (WMLs) are suggested to predict a more severe disease course. Only small longitudinal cohorts of patients with and without iron rim lesions (IRLs) have been reported so far. OBJECTIVE: To assess whether the presence and number of IRLs in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS) are associated with long-term disability or progressive disease. METHODS: Ninety-one CIS/MS patients were recruited between 2008 and 2013 and scanned with 7 T magnetic resonance imaging (MRI). Expanded Disability Status Scale (EDSS) was used to calculate Age-related Multiple Sclerosis Severity Score (ARMSS) at the time of scan and at the latest clinical follow-up after 9 years. WMLs were assessed for the presence of IRL using Susceptibility weighted imaging (SWI)-filtered phase images. RESULTS: In all, 132 IRLs were detected in 42 patients (46%); 9% of WMLs had IRs; 54% of the cohort had no rims, 30% had 1-3 rims and 16% had ⩾4. Patients with IRL had a higher EDSS and ARMSS. Presence of IRL was also a predictor of long-term disability, especially in patients with ⩾4 IRLs. IRLs have a greater impact on disability compared to the WML number and volume. CONCLUSION: The presence and number of perilesional IR on MRI hold prognostic value for long-term clinical disability in MS.

Magnetic Resonance Imaging as a Prognostic Disability Marker in Clinically Isolated Syndrome and Multiple Sclerosis: A Systematic Review and Meta-Analysis.

To date, there are no definite imaging predictors for long-term disability in multiple sclerosis (MS). Magnetic resonance imaging (MRI) is the key prognostic tool for MS, primarily at the early stage of the disease. Recent findings showed that white matter lesion (WML) counts and volumes could predict long-term disability for MS. However, the prognostic value of MRI in the early stage of the disease and its link to long-term physical disability have not been assessed systematically and quantitatively. A meta-analysis was conducted using studies from four databases to assess whether MS lesion counts and volumes at baseline MRI scans could predict long-term disability, assessed by the expanded disability status scale (EDSS). Fifteen studies were eligible for the qualitative analysis and three studies for meta-analysis. T2 brain lesion counts and volumes after the disease onset were associated with disability progression after 10 years. Four or more lesions at baseline showed a highly significant association with EDSS 3 and EDSS 6, with a pooled OR of 4.10 and 4.3, respectively. The risk increased when more than 10 lesions were present. This review and meta-analysis confirmed that lesion counts and volumes could be associated with disability and might offer additional valid guidance in treatment decision making. Future work is essential to determine whether these prognostic markers have high predictive potential.

Clinical and Therapeutic Characteristics of Cancer Patients in the Southern Region of Saudi Arabia: A Cross-Sectional Study.

AIMS: Due to the continuous changes in modern lifestyle and the need to explore the effect of these changes on the risk of developing cancer, ongoing research on the epidemiology and characteristics of cancer patients is requested. This study explored the epidemiology of cancer, its characteristics, treatment patterns, and risk factors in the southern region of Saudi Arabia. METHODS: A retrospective cross-sectional study was conducted using cancer patients' medical records at Asir Central Hospital in the southern region of Saudi Arabia. Active patients' records were extracted between January 2013 and December 2019. RESULTS: A total of 2038 patients were identified during the study period, with a mean age of 60.9 (SD: 19.0) years. The patients had survived with their cancer for a median duration of 4 years (IQR: 2-6). Around 4.6% of the patients required ICU admission with a median period of 9 days (IQR: 5-14.75). The death rate during the study period was 10.9%. Around 20.8% of the cases were metastatic, of which 77.8% were at stage four of metastasis, and 19.7% of the patients were receiving chemotherapy for their disease. The most common types of cancer were malignant neoplasms of digestive organs, comprising 40.8% of the sample. Older age (60 years and above) and using specific chronic disease medications were predictors associated with a higher risk of death due to cancer (p < 0.05). Smoking history, using specific chronic disease medications, and having previous surgery were predictors associated with a higher risk of ICU admission (p < 0.05). CONCLUSION: Breast, colon, and liver cancers were the most prevalent in the southern region of Saudi Arabia. Several modifiable cancer risk factors were identified. The results of this study should support decision-makers in the initiation of programs for key modifiable risk factors that enhance lifestyle changes and reduce cancer risks.

Isolation and identification of Saccharomyces cerevisiae for fermentation of rice polishing in Livestock feeding.

Biomass of Saccharomyces cerevisiae wasenhancedin rice polishing by fermentation to increase protein contents of feedfor its use in livestock. Broth culture of Saccharomyces cerevisiae (2.6×108CFU/mL) was prepared from culture obtained by continuous streaking. The isolated culture was identified morphologically by Gram staining and confirmed by biochemical characteristics. Rice polishing was sieved to remove larger particles. Then it was distributed to 4 treatments in triplicates. Treatments were represented as rice polishing (RP), rice polishing plus Saccharomyces culture (RPSC), rice polishing plus ammonium sulphate (RPAS), rice polishing plus Saccharomyces culture plus ammonium sulphate (RPSCAS).Fermentation was provided for 144 hours at 320C,while samples were collected after every 24 hours. Samples were dried, ground and subjected to proximate analysis. It was observed that protein content was increased from 11% to 21.51% and maximum increment was obtained after 144 hours of incubation in RPSC treatment. Ether extract and ash were increased from 14% and 10% to 16.96% and 11.11% in RPSCAS respectively. A significant reduction in neutral detergent fiber was observed after fermentation. It is concluded that Saccharomyces cerevisiae has potential to improve mineral and protein contents of rice polishing by fermentation process with or without addition of nitrogen source.

Iron Rims as an Imaging Biomarker in MS: A Systematic Mapping Review.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune, inflammatory, demyelinating and degenerative disease of the central nervous system (CNS). To date, there is no definitive imaging biomarker for diagnosing MS. The current diagnostic criteria are mainly based on clinical relapses supported by the presence of white matter lesions (WMLs) on MRI. However, misdiagnosis of MS is still a significant clinical problem. The paramagnetic, iron rims (IRs) around white matter lesions have been proposed to be an imaging biomarker in MS. This study aimed to carry out a systematic mapping review to explore the detection of iron rim lesions (IRLs), on clinical MR scans, and describe the characteristics of IRLs presence in MS versus other MS-mimic disorders. METHODS: Publications from 2001 on IRs lesions were reviewed in three databases: PubMed, Web of Science and Embase. From the initial result set 718 publications, a final total of 38 papers were selected. RESULTS: The study revealed an increasing interest in iron/paramagnetic rims lesions studies. IRs were more frequently found in periventricular regions and appear to be absent in MS-mimics. Conclusions IR is proposed as a promising imaging biomarker for MS.

Non-specific chronic low back pain and physical activity: A comparison of postural control and hip muscle isometric strength: A cross-sectional study.

Most research on sedentary lifestyle has focused on pain and disability, while neuromuscular outcomes (postural control and strength) have received less attention. The objective of the study was to determine whether low level of physical activity is negatively associated with measures of lower body muscular strength and postural control in individuals with and without non-specific chronic low back pain (NSCLBP).Twenty-four subjects with NSCLBP (28.8 ±â€Š5.9 years) and 24 age, gender, and body mass index matched healthy controls participated in the study. Subjects were sub-classified into 4 subgroups based on their physical activity level: Non-active NSCLBP; Active NSCLBP; Non-active healthy control; and Active healthy control. Each subgroup consisted of 12 subjects. Peak force of hip muscles strength was assessed using a handheld dynamometer. Postural control was assessed using computerized posturography and the Y Balance Test.There was no significant group by physical activity interaction for strength and static and dynamic postural control, except for static control during left single leg stance with eyes closed (P = .029). However, there was a significant difference in strength and postural control by physical activity (P < .05). Postural control and peak force of hip muscles strength were significantly associated with physical activity (r ranged from 0.50 to 0.66, P < .001 and r ranged from 0.40 to 0.59, P < .05, respectively).Postural control and hip strength were independently related to physical activity behavior. A sedentary behavior may be an important risk factor for impaired postural control and hip muscles strength, and that physical fitness is vital to neuromuscular outcomes.

Increased Complement Factor B and Bb Levels Are Associated with Mortality in Patients with Severe Aortic Stenosis.

Inflammation is involved in initiation and progression of aortic stenosis (AS). However, the role of the complement system, a crucial component of innate immunity in AS, is unclear. We hypothesized that circulating levels of complement factor B (FB), an important component of the alternative pathway, are upregulated and could predict outcome in patients with severe symptomatic AS. Therefore, plasma levels of FB, Bb, and terminal complement complex were analyzed in three cohorts of patients with severe symptomatic AS and mild-to-moderate or severe asymptomatic AS (population 1, n = 123; population 2, n = 436; population 3, n = 61) and in healthy controls by enzyme immunoassays. Compared with controls, symptomatic AS patients had significantly elevated levels of FB (2.9- and 2.8-fold increase in population 1 and 2, respectively). FB levels in symptomatic and asymptomatic AS patients were comparable (population 2 and 3), and in asymptomatic patients FB correlated inversely with valve area. FB levels in population 1 and 2 correlated with terminal complement complex levels and measures of systemic inflammation (i.e., CRP), cardiac function (i.e., NT-proBNP), and cardiac necrosis (i.e., Troponin T). High FB levels were significantly associated with mortality also after adjusting for clinical and biochemical covariates (hazard ratio 1.37; p = 0.028, population 2). Plasma levels of the Bb fragment showed a similar pattern in relation to mortality. We concluded that elevated levels of FB and Bb are associated with adverse outcome in patients with symptomatic AS. Increased levels of FB in asymptomatic patients suggest the involvement of FB from the early phase of the disease.

Age-dependent morbidity and mortality outcomes after surgical aortic valve replacement.

OBJECTIVES: This study addressed the assumption of increased morbidity and mortality after surgical aortic valve replacement in patients older than 80 years with severe aortic stenosis. METHODS: This prospective study was performed in consecutive patients referred for aortic valve replacement. The age-dependent change in cognitive and physical function, quality of life and rehospitalization and complication rates during the following year and 5-year all-cause mortality were documented. RESULTS: A total of 351 patients underwent surgical aortic valve replacement. The death risk at 5 years was 10%, 20% and 34% in patients aged <70 years, 70-79 years and ≥80 years, respectively. Patients aged 70-79 years and ≥80 years had a hazard ratio of 1.88 [95% confidence interval (95% CI) 0.92-3.83, P = 0.08] and 2.90 [95% CI 1.42-5.92, P = 0.003] for mortality, respectively, when compared with patients aged <70 years. The length of stay and rehospitalization rate during the following year were similar between the groups. Patients ≥80 years of age experienced more delirium and infections, whereas the risks of new pacemaker, transient ischaemic attack (TIA) or stroke, myocardial infarction and heart failure were comparable between the age groups. All groups exhibited reduced New York Heart Association class, improved physical quality of life and unchanged mental scores without any clinically significant Mini Mental Status reduction. CONCLUSIONS: Elderly patients (≥80 years of age) have important gains in health measures and satisfactory 5-year survival with an acceptable complications rate during the year following surgery. Active respiratory mobilization and the removal of an indwelling urethra catheter can prevent adverse effects, and measures should be taken to prevent delirium and confusion in elderly patients. Clinical trial registration: clinicaltrials.gov (NCT 01794832).

Patient-reported outcomes after referral for possible valve replacement in patients with severe aortic stenosis.

OBJECTIVES: Health-related quality of life (HRQoL) is an important outcome after surgical aortic valve replacement (SAVR). To improve interpretation of HRQoL, mean score change and change in terms of minimal important difference (MID) were assessed using validated instruments for measuring patient-reported outcomes in patients with severe aortic stenosis referred for possible SAVR. METHODS: Of the 442 included patients with severe aortic stenosis evaluated for possible SAVR, 351 were referred to SAVR (operated) and 91 to medical treatment (unoperated). At presurgical evaluation and 1 year postoperatively, HRQoL was assessed using SF-36v2 and EQ-5D. Results were compared with outcomes reported in unoperated patients. We explored the association of clinical factors and improvements corresponding to MID. RESULTS: Among the operated patients, statistically significant change was found for EQ-5D scores and SF-36 scale scores for physical functioning, role-physical, bodily pain, general health, vitality and physical summary score. The largest proportion of operated patients achieving change corresponding to at least MID was 61.5% for physical summary score. Change in unoperated patients also related largely to physical scales of the SF-36. However, smaller proportions of unoperated patients reported improvements, and larger proportions reported decline reaching MID. Baseline scores, but no clinical covariates, were consistently associated with improved HRQoL reaching MID across instruments for those referred to SAVR. CONCLUSIONS: This study found improvement in HRQoL 1 year after SAVR for patients with severe aortic stenosis. Results in unoperated patients suggest that HRQoL deteriorates 1 year after evaluation of possible SAVR. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01794832).

Determinants and Outcome of Decision Making Among Patients with Severe Aortic Stenosis.

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) improves survival and quality of life in patients with severe aortic stenosis (AS), but despite clear indications for surgical treatment a significant proportion of patients do not undergo AVR. The study aim was to identify clinical variables associated with the decision to perform AVR, and to assess the prognostic effect of surgery versus medical treatment in patients with severe AS adjusted for significant confounders and effect modifiers. METHODS: A prospective observational study of consenting patients aged >18 years who were under consideration for AVR at the authors' tertiary teaching hospital was conducted. The main outcomes of the study were treatment decisions and survival. RESULTS: Among 480 patients with severe AS who were evaluated, 351 had surgical AVR, 38 had transcatheter AVR, and 91 were declined operative treatment. Typically, non-operated patients were older, were in a lower NYHA class, had fewer symptoms, a lower peak aortic jet velocity, a higher NT-proBNP level, and a lower physical summary score (SF-36). Higher age showed the strongest correlation against AVR (OR 0.91; 95% CI 0.87-0.94). One-, three-, and five-year cumulative survival rates, respectively, were 95%, 87%, and 73% among operated patients, and 82%, 47%, and 27% among non-operated patients. The median survival time was 1,604 days (95% CI 1,554-1,655) in operated patients versus 1,090 days (95% CI 954-1,226) in non-operated patients (p <0.001). The effect of operation on mortality was shown to depend on the interaction with diabetes, when adjusted for significant confounders (i.e., age, atrial fibrillation, NT-proBNP, hs-Troponin T, and NYHA class). An effect of AVR on mortality was found in patients without diabetes (HR 0.29; 95% CI 0.19-0.468; p <0.001), but not among patients with diabetes. CONCLUSIONS: Supplemental and better parameters to improve patient selection are warranted. Surgical AVR shows a greater prognostic effect in patients without diabetes.

Eliciting Patient Risk Willingness in Clinical Consultations as a Means of Improving Decision-Making of Aortic Valve Replacement.

BACKGROUND: Treatment decisions for aortic valve replacement (AVR) should be sensitive to patient preferences. However, we lack knowledge of patient preferences and how to obtain them. METHODS AND RESULTS: We assessed the mortality risk patients were willing to accept when undergoing AVR by using the Standard Gamble method and aimed to show how this risk willingness was affected by level of disease burden. We report findings from 439 patients, aged >18 years with severe aortic stenosis who were referred for evaluation of AVR to our institution. The vast majority of patients accepted a mortality risk regarded as high or prohibitive according to current guidelines. Of the 439 patients, 51% patients were willing to forego surgery with high mortality risk (8-50%) and 19% were willing accept a prohibitive mortality risk (>50%) as defined in current guidelines. However, the risk willingness varied considerably. Acceptance of prohibitive risk willingness (>50%) was associated with reporting of 3 to 5 different restricting symptoms, with an odds ratio of 4.07 (95% CI 1.56-10.59) opposed by increasing score on EuroQol-Visual Analog Scale, with an odds ratio of 0.99 (95% CI 0.97-1.00). The poor ability to predict risk willingness based on available clinical variables and health status suggests that other factors may be important advocating the need for tools for soliciting patient's preferences individually. CONCLUSION: When undergoing AVR, patients were willing to accept considerably higher perioperative risk than what is considered acceptable in current guidelines and practice. Patient preferences varied considerably, and they should be directly assessed and taken into account in decision-making and guidelines. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov/. Unique identifier: NCT01794832.

Validity of standard gamble utilities in patients referred for aortic valve replacement.

PURPOSE: Standard gamble (SG) is the preferred method of assessing preferences in situations with uncertainty and risk, which makes it relevant to patients considered for aortic valve replacement (AVR). The present study assesses SG preferences in patients with severe aortic stenosis (AS). METHODS: All patients >18 years old with severe AS referred for AVR to our institution were invited to enroll in the study. The SG was administered by a clinical research nurse. The SF-36, EQ-5D 3L, Hospital Anxiety and Depression Scale (HADS), and AS symptoms were administered by self-completed questionnaire. We hypothesized that SG utilities would have low-to-moderate correlations with physical and mental aspects of health based on our pathophysiological understanding of severe AS. No correlations were expected with echocardiographic measures of the aortic valve. RESULTS: The response rate for SG was 98 %. SG moderately correlated with physical aspects of SF-36 (PCS, role-physical, vitality), health transition, AS symptoms, and EQ-VAS (ρ S = 0.31-0.39, p < 0.001) and had low correlation with mental aspects of SF-36 and EQ-5D (ρ S = 0.17-0.28, p < 0.001). No correlation was found between SG and HADS, echocardiographic measures, age, gender, or education level (ρ S = 0.01-0.06). CONCLUSIONS: SG is an acceptable and feasible method of assessing preferences in patients with severe AS that has evidence for validity. The inclusion of uncertainty lends the SG face validity in this population as a direct approach to assessing preferences and basis for QALY calculations.

Genetic characterization of clinical acanthamoeba isolates from Japan using nuclear and mitochondrial small subunit ribosomal RNA.

Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear sub-conformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

Genetic Characterization of Clinical Acanthamoeba Isolates from Japan using Nuclear and Mitochondrial Small Subunit Ribosomal RNA

Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear sub-conformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitals.

Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1, dfrA5, dfrA7, dfrA12, dfrA17 and dfrA25; aminoglycoside adenyltransferases, aadA1, aadA2, aadA5, aadA12 and aadB; aminoglycoside acetyltransferase, aac(6')-Ib; and chloramphenicol resistance gene, cmlA1. ESBL were identified in 25 (41.7%) isolates. The identified ESBL were bla(CTX-M-15), bla(CTX-M-56), bla(OXA-1), bla(SHV-1), bla(SHV-12), bla(SHV-32) and bla(TEM-1) genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr and qnrB2, which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time.

Multiple-subgenotype infections of Giardia intestinalis detected in Palestinian clinical cases using a subcloning approach.

To evaluate the geographic distribution of Giardia intestinalis genotypes in Nablus, West Bank, Palestine, a genotyping study was performed using clinical fecal samples. Microscopic examination confirmed that 8 of 69 (11.6%) samples were G. intestinalis positive, and subsequent genotyping analyses targeting the small-subunit ribosomal RNA (18S rRNA) and glutamate dehydrogenase (GDH) genes revealed the G. intestinalis genotypes within the 8 samples. Of these 8 samples, 6 were clustered with assemblage A-II and the remaining 2 samples were clustered with assemblage B by 18S rRNA gene analysis; however, direct sequencing of the GDH gene segments from the latter 2 samples showed a mixed infection profile. To assess those samples, we employed a subcloning approach and successfully isolated 6 independent assemblage B subgenotypes. These partial GDH gene sequences (393 bp) had 15 single-nucleotide polymorphisms, all of which were synonymous transition substitutions at the third nucleotide position of codons. From the results, we concluded that the highly polymorphic gene loci such as GDH gene locus might provide us an opportunity to obtain a detailed molecular data even from the samples with multiple-subgenotype mixed infections. Therefore, subcloning approach is recommended in genotyping studies, especially in those conducted in giardiasis-endemic areas, where the repeated and cumulative infections could be commonly expected.