Black aspergilli as causes of otomycosis in the era of molecular diagnostics, a mini-review

Otomycosis refers to the fungal infection of the external auditory canal, and less commonly the middle ear. A wide range of fungi can cause this disease, however, the most common etiologies are species of Aspergillus and Candida. Until recent years, Aspergillus niger was thought to be the prevailing species of the genus Aspergillus that causes otomycosis. Using molecular methods, now, it is known that Aspergillus section Nigri comprises several morphologically similar species and all black Aspergillus isolates are not necessarily equivalent to Aspergillus niger. In this review, we focus on the species within the Aspergillus section Nigri and their role as the causative agents of otomycosis.

Bacterial etiology and antibiotic resistance pattern of pediatric bloodstream infections: A multicenter based study in Tehran, Iran

BACKGROUND

Due to the diverse nature of bloodstream infections etiology and to the antibiotic resistance patterns in periodic intervals, rational and accurate use of antibiotics requires an understanding of common causative agents of septicemia and their susceptibility patterns. The present study aimed to determine the bacterial etiology of the neonate and pediatric septicemia, and their antibiotic resistance pattern in Tehran, North of Iran.

MATERIAL AND METHODS

This retrospective cross-sectional study was conducted along two years, from October 2014 to November 2016 among children with suspected bloodstream infection. Blood specimens were collected aseptically in BACTECTM blood bottles, and standard microbiological methods were applied for the isolation and identification of the bacteria. Antimicrobial susceptibility tests were performed using the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations.

RESULTS

Overall, 433 (21.1%) blood cultures showed a significant bacterial growth. Gram-negative bacteria with a proportion of 55.4% were the predominant isolates. The most frequently isolated Gram-negative bacteria were Pseudomonas spp. (26.8%), followed by Klebsiella spp. (8.8%), and Acinetobacter spp. (7.9%). Ciprofloxacin, amikacin, and piperacillin/tazobactam had the highest antibacterial effect on non-fermenting Gram-negative bacilli. Regarding the recovered Enterobacteriaceae, aminoglycosides and carbapenems showed a promising effect for tested isolates. The prevalence of methicillin-resistant S. aureus and coagulase-negative staphylococci were 52.6%, and 78.6%, respectively. The rate of vancomycin-resistant enterococci was estimated 68.8%. Meanwhile, the overall prevalence of multiple-drug resistant isolates was 83.4.

CONCLUSION

Regarding results, Multiple Drug Resistant isolates had a significant role in the occurrence of bloodstream infections. Hopefully, several locally available antibiotics still have promising effects on these isolates.

Invasive fungal consecutive infections in a patient with acute myeloid leukaemia

A woman with AML who became febrile and neutropenic after chemotherapy. At the first, Aspergillus was isolated from a sinus biopsy. After 4 weeks, while she was taking voriconazole, another episode of fever combined with dry coughs was detected. Fungal culture and histopathology of sinus biopsy revealed mucormycosis.

Ventilator-associated pneumonia in a teaching hospital in Tehran and use of the Iranian Nosocomial Infections Surveillance Software

Ventilator-associated pneumonia is the most common health-care-associated infection in the intensive care unit (ICU) and computer-assisted diagnosis and surveillance is called for. The frequency of ventilator-associated pneumonia was assessed prospectively during a 6-month period in the ICUs of a teaching hospital in Tehran, Islamic Republic of Iran. To determine the accuracy of the Iranian Nosocomial Infections Surveillance (INIS) system, patient data were input to the software and compared with physicians' judgement. The frequency of ventilator-associated pneumonia was 21.6%, or 9.96 episodes per 1000 ventilator days. The duration of admission to the ICU, duration of mechanical ventilator and number of re-intubations were significantly higher in patients who developed pneumonia. The INIS system identified 100% of cases, with no false-positive or false-negative results. Compared with developed countries, the frequency of ventilator-associated pneumonia was high in our ICUs, and INIS software was accurate in diagnosing nosocomial infection.

Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig

To explore the coordinative characteristics of tongue deformation, muscle activity and jaw movement during feeding, six ultrasonic crystals were implanted into the tongue body of ten 12-week-old Yucatan minipigs 1 week before the recording. These crystals formed a wedge-shaped configuration to allow recording dimensional changes in lengths, anterior and posterior widths and posterior thicknesses of the tongue body during feeding. Wire electromyographic activities (EMG) of superior and inferior longitudinalis, verticalis/transversus, genioglossus, styloglossus, masseter and digastricus and jaw movements were recorded simultaneously. Signals from these three sources were synchronized for real-time analyses. The results indicate: (i) dimensional changes were stereotypical in relation to each cycle of all three feeding behaviours; (ii) during chewing, expansion of tongue widths mainly occurred in the occlusal phase of jaw movement and was less coupled with the activity of tongue muscles, but the expansions of length and thickness were seen in the opening and closing phases and were better coupled with the activity of tongue muscles (P < 0.05); (iii) ingestion was characterized by the two-phased jaw opening, early expansion of anterior width prior to the occlusal phase and strong associations between tongue deformation and muscle activity; (iv) during drinking, the duration of the opening and closing phases was significantly prolonged (P < 0.01), the durations of tongue widening and lengthening were significantly shortened (P < 0.05) and anterior widening was predominant in the opening rather than in the closing or occlusal phases as compared with chewing and ingestion; and (v) the intrinsic tongue muscles did not show more or stronger correlations with the tongue deformation than did the extrinsic tongue muscles. These results suggest that (i) regional widening, lengthening and thickening of the tongue body occurs sequentially in relation to jaw movement phases, but the initiation of tongue dimensional expansions does not correspond with the activation of tongue muscles simultaneously; (ii) there is a better coupling between tongue deformations and tongue muscle activations in the sagittal (lengthening and thickening) than the transverse (widening) planes; and (iii) the patterns and ranges of tongue deformation and their relations to muscle activity and jaw movement are task-specific and the expansion magnitudes of tongue deformation does not have closer correlations with the amount of EMG activity in the intrinsic than the extrinsic tongue or jaw muscles.

Insulin adsorbance to polyvinylchloride (PVC) surfaces of fluid container and infusion-set

INTRODUCTION

In total parenteral nutrition (TPN) solution, adsorbance of insulin to polyvinylchloride (PVC) surfaces of fluid containers and infusion-sets, decrease the amount of insulin that reaches the patients.

OBJECTIVE

To clarify the biding sites of insulin and to propose a solution to overcome this problem.

METHODS AND MATERIALS

To each of four 1000ml. PVC bottles of 5 percent dextrose solution, 300 microunit of insulin per each milliliter of dextrose solution were added. Each bottle was then connected to an infusion-set and the system made to run at an infusion rate of 100ml. per hour. One milliliter samples were then collected from both the PVC bottles and infusion-sets-terminal, separately, immediately at the starting point (time zero) and 15, 30, 45 and 60 minutes thereafter. The concentrations of insulin were checked using insulin kits.

RESULTS

At the starting point (time zero) the mean of insulin concentrations among four PVC bottles was 213.79 microunit per each milliliter of 5 percent dextrose solution. No significant fluctuation was noted in the concentration of insulin in the PVC bottles through 60th minute period. However the concentration of insulin at infusion-set- terminal decreased significantly at the end of the same hour (p. value = 0.004).

CONCLUSION

Our results demonstrate that the adsorbance of insulin takes place at the surfaces of infusion sets. It follows therefore that increase in the primary dosage of insulin added to PVC infusion solutions and the selection of a suitable infusion set (polyethylene) seem to be beneficial for overcoming this problem.