Evaluation of multidrug resistance patterns in siderophore-producing Pseudomonas aeruginosa from clinical and environmental samples in Gorgan, Iran.

Siderophores secreted by nonfermentative negative bacilli such as Pseudomonas aeruginosa are capable of increasing rates of resistance to carbapenem antibiotics. Furthermore, the resistance of these isolates to antibiotics has been enhanced by producing siderophores, and their frequencies have erratic patterns. We studied the outbreak of P. aeruginosa strains and their antibiotic patterns in different clinical samples. In this descriptive cross-sectional study, 100 P. aeruginosa samples were isolated from different clinical specimens at the 5th Azar Hospital, Gorgan, Iran, in 2017. These strains were identified by biochemical tests, and their antibiotic resistance patterns were measured via the disc diffusion method. Next imipenem and EDTA-imipenem (10-30 µg) antibiotics were employed for the detection of siderophores. Amongst 100 P. aeruginosa samples, 31 isolates (31%) were siderophore carriers. The frequency of this enzyme among specimens was as follows: 56.2% in burn wounds, 36.4% in urine, 22.2% in respiratory secretion, 19.4% in blood and 16.7% in wounds (p > 0.05). Moreover, P. aeruginosa isolates producing siderophores had the highest range of resistance to ciprofloxacin (47.6%), gentamicin (46.7%), ceftazidime (34.9%), nalidixic acid (34.3%), amikacin (34.1%) and cefotaxime (31.6%). The prevalence of siderophore producers, and especially their antibiotic patterns have no specific algorithms; in addition, an antibiogram is recommended to identify the most effective antibiotics against those isolates.

Genetic screening in Iranian patients with retinoblastoma.

PurposeThe most common intraocular tumor in childhood, retinoblastoma, is largely associated with mutations in the RB1 gene. In the most comprehensive RB1 screening in Iran, we evaluated the RB1 mutations in 106 patients with retinoblastoma, including 73 bilateral (heritable) and 33 unilateral (sporadic) cases.Patients and methodsMutations were identified using amplification refractory mutation system (ARMS) PCR and direct sequencing of the 27 coding exons of RB1 and multiplex ligation-dependent probe amplification (MLPA).Results and ConclusionWe found 33 (31%) and 64 (60%) patients with sporadic unilateral and bilateral retinoblastoma, respectively as well as 9 (8.5%) cases with hereditary bilateral retinoblastoma. In total, we identified 52 causative RB1 mutations in 106 patients (global mutation rate of 49%). Of the 52 patients, 48 (92%) had sporadic and familial bilateral and 4 (8%) had sporadic unilateral RB. Therefore, the detection rate of RB1 mutations was 66% (48/73) and 12% (4/33) in bilateral and unilateral cases, respectively. Mutations were classified as nonsense in 31 (60%), missense in 1 (2%), large deletion in 11 (21%), small deletion in the 7 novel (15%) and splice site mutation in 2 (4%) patients with RB. Of 31 nonsense mutations, 23 (74%) occurred in the 11 Arginine codons of the RB1. Seven mutations (13%) were novel, and 45 (87%) had been previously reported. Thirty-three mutations were single-base substitutions leading to 31 nonsense amino acid changes and 2 splice site mutations in introns 12 and 16 of RB1. The altered 3D model structures of the RB1 novel mutant proteins are also predicted in this study.

Analysis of partial azoospermia factor c deletion and DAZ copy number in azoospermia and severe oligozoospermia.

Microdeletions of the azoospermia factor (AZF) regions in the Y chromosome are a well-known genetic cause of male infertility, resulting in impairment of spermatogenesis. However, the partial deletions of AZFc region related to spermatogenetic impairment are controversial. We investigated partial deletion of AZFc region and DAZ copy number in a population of Iranian infertile men and normozoospermic controls. In total, 154 infertile men (113 patients with azoospermia, 41 with oligozoospermia) and 111 normozoospermic controls were analysed using PCR. Gene dosage analysis of the DAZ genes was performed by fragment analysis. Our results showed that the frequencies of gr/gr deletion in the azoospermic, severe oligozoospermic and normozoospermic men were 4.4% (5/113), 7.3% (3/41) and 1.8% (2/111) respectively. In the azoospermic patients, the frequency of b2/b3 was 1.8% (2/113). Partial AZFc deletions were not significantly different between the infertile and normozoospermic men. The frequencies of gr/gr deletions and b2/b3 were not significantly different between the azoospermic/severe oligozoospermic men and normozoospermic controls. Our data suggested that gr/gr deletion was not associated with azoospermia/oligozoospermia in an Iranian population.

Nonlinear solution for radiation boundary condition of heat transfer process in human eye.

In this paper we propose a new method based on finite element method for solving radiation boundary condition of heat equation inside the human eye and other applications. Using this method, we can solve heat equation inside human eye without need to model radiation boundary condition to a robin boundary condition. Using finite element method we can obtain a nonlinear equation, and finally we use nonlinear algorithm to solve it. The human eye is modeled as a composition of several homogeneous regions. The Ritz method in the finite element method is used for solving heat differential equation. Applying the boundary conditions, the heat radiation condition and the robin condition on the cornea surface of the eye and on the outer part of sclera are used, respectively. Simulation results of solving nonlinear boundary condition show the accuracy of the proposed method.

A five-year retrospective study of odontogenic maxillofacial infections in a large urban public hospital.

The aim of this study was to analyze the etiology, presentation, management and outcome of odontogenic maxillofacial infections seen in an urban population that has only one major public hospital, which is also the only level I trauma center. All patients admitted to the Oral and Maxillofacial Surgery Service of San Francisco General Hospital with odontogenic infections over a 5-year period were included. Age, gender, site of infection, investigations performed, treatment carried out and outcomes were studied. Length of hospital stay and any readmissions were also noted. A total of 250 patients were admitted with maxillofacial infections, and in 157 cases the infection was odontogenic in origin. Males outnumbered females (102:55). Children had a preponderance of maxillary buccal infections whilst adults had more mandibular infections. Hospital stays ranged from 1 to 23 days, and only one patient required re-admission. A wide range of antibiotics were prescribed and 122 patients required dental extractions. Odontogenic maxillofacial infections are a public and personal health issue with potential life-threatening complications. This study identifies potential risk factors and suggests that early dental extraction, incision and drainage, coupled with intravenous antibiotic therapy, is the most effective treatment. Antibiotic therapy can be empirical since in no case where cultures were performed did this alter the antibiotic management.