Aspergillus Is Inhibited by Pseudomonas aeruginosa Volatiles

BACKGROUND: Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) compete with each other for nutrients and survival in natural environments, and have been extensively studied because of their intermicrobial interactions in the human microbiome. These are the principal microbes infecting immunocompromised patients and persons with cystic fibrosis, particularly the airways. These intermicrobial studies have largely been conducted in liquid medium or on agar, and thus focus on soluble or diffusible microbial products. Several key inhibitory molecules were defined in such studies. METHODS: in the present report, we examine several methodologies which can be conveniently used to study the interaction of microbial volatiles, including capture methods and kinetics. RESULTS: Pa volatiles inhibit Af, and the inhibitory mechanism appears to be the incorporation of the inhibitory molecules into the substrate nourishing the Af, rather than directly onto Af structures. We define by mass spectroscopy some specific volatile Pa products that can inhibit Af. Some of these molecules are selected for interest by the study of gene deletion mutants, producing a few Pa strains that were impaired in inhibition. We presumed the volatiles of these latter strains could be excluded from the search for inhibitors. CONCLUSION: the Pa inhibition of Af via a gaseous phase could be critical components in their competition, particularly in airways, where more direct contact may not be extensive.</p

Molecular modifications of the pseudomonas quinolone signal in the intermicrobial competition with aspergillus

The Pseudomonas quinolone signal (PQS) is an important quorum-sensing molecule for Pseudomonas aeruginosa that regulates virulence factors, chelates iron, and is an important factor in interactions with eukaryotes, including fungi and mammalian hosts. It was previously shown to inhibit or boost Aspergillus, depending on the milieu iron concentration. We studied several molecular modifications of the PQS molecule, and their effects on Aspergillus biofilm metabolism and growth in vitro, and the effects of iron supplementation. We found that most molecules inhibited Aspergillus at concentrations similar to that of PQS, but with relatively flat dose-responses, and all were less potent than PQS. The inhibition was reversible by iron, suggesting interference with fungal iron metabolism. Stimulation of Aspergillus was not noted. We conclude that the critical Aspergillus-inhibiting moeities of the PQS molecule were partially, but not completely, interfered with by molecular modifications at several sites on the PQS molecule. The mechanism, as with PQS, appears to relate to fungal iron metabolism

Live imaging and quantitative analysis of Aspergillus fumigatus growth and morphology during inter-microbial interaction with Pseudomonas aeruginosa

Pseudomonas aeruginosa (PA) and Aspergillus fumigatus (AF) chronically colonize the airways of patients with cystic fibrosis or chronic immunosuppression and mutually affect each other's pathogenesis. Here, we evaluated IncuCyte time-lapse imaging and NeuroTrack(TM) (NT) analysis (Wurster et al., 2019, mBio) as a toolbox to study mycelial expansion and morphogenesis of AF during interaction with PA. Co-incubation of AF with supernatant filtrates of wild-type (WT) PA strains strongly inhibited hyphal growth and branching. Consonant with prior metabolic studies, pyoverdine-deficient PA mutants had significantly attenuated inhibitory capacity. Accordingly, purified PA products pyoverdine and pyocyanin suppressed mycelial expansion of AF in a concentration-dependent way. Using fluorescence-guided tracking of GFP-AF293 mycelia during co-culture with live WT PA cells, we found significant inoculum-dependent mycelial growth inhibition and robust precision of the NT algorithm. Collectively, our experiments position IncuCyte NT as an efficient platform for longitudinal analysis of fungal growth and morphogenesis during bacterial co-infection.</p

Examination of the Ovarian Reserve after Generation of Unilateral Rudimentary Uterine Horns in Rats

Objective. The purpose of this experimental rat model study is to evaluate the changes in the ovarian environment after excision of the rudimentary horn. Methods. Ten female Wistar albino rats were used in this study. One cm of right uterine horn length was excised in the first operation. Two months after the first operation, all animals were sacrificed to obtain ovaries for histological examination. Mann-Whitney U test and Student's t-test were used for statistical analysis purposes. Statistical significance was defined as P<0.005. Results. The number of primordial follicles (P=0.415), primary follicles (P=0.959), preantral follicles (P=0.645), antral follicles (P=0.328), and Graafian follicles (P=0.721) was decreased and the number of atretic follicles (P=0.374) increased in the right ovarian side. Howeve,r this difference was not found to be statistically significant. Conclusion. The results of this experimental rat model study suggest that the excision of rudimentary horn could have negative effects on ipsilateral ovarian functions

Sexual functions and prolactin levels in patients with bipolar disorder

Objective: Mood stabilizers and antipsychotic drugs are known to have adverse effects on sexual function. However, patients often refrain from speaking about sexual complaints that may cause dose reduction and discontinuation of the drug without medical supervision. In this study we aimed to evaluate sexual functions of patients with bipolar disorder in remission period, considering prolactin levels and medications. Method: We recruited 52 patients with bipolar disorder in remission according to DSM-IV diagnostic criteria. Prolactin levels were measured in all patients. The Golombok Rust Inventory of Sexual Satisfaction (GRISS) was used to assess sexual dysfunction. Results: Mean prolactin levels were 24.71 ± 4.25 and 19.96 ± 5.52 ng/ml respectively for females and males. Patients taking mood stabilizer (MS) and mood stabilizer plus antipsychotic (AP) treatment had different prolactin levels (p<0.001). Total GRISS scores were not different for MS and MS+AP treatment groups. We didn't find a correlation between Total GRISS scores and prolactin levels. There was a significant deterioration in female non-sensuality, female dissatisfaction and anorgasmia subscales of female patients and significant deterioration in premature ejaculation, impotence and male dissatisfaction subscales of male patients. Discussion: In our sample, both men and women patients with bipolar disorder in remission have sexual dysfunctions. Our results suggest that prolactin levels are not sufficient to demonstrate the sexual dysfunction. To enhance patient compliance it is necessary to focus more on sexual symptoms of patients receiving MS and AP treatment

External decontamination of wild leeches with hypochloric acid

BACKGROUND: Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated. METHODS: Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution. RESULTS: Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly. CONCLUSIONS: External decontamination of wild leeches with 12.5 ppm hypochloric acid enables bacterial suppression without causing negative effects on leech sucking function and life

Evaluation of nutritional status in pediatric intensive care unit patients: the results of a multicenter, prospective study in Turkey

IntroductionMalnutrition is defined as a pathological condition arising from deficient or imbalanced intake of nutritional elements. Factors such as increasing metabolic demands during the disease course in the hospitalized patients and inadequate calorie intake increase the risk of malnutrition. The aim of the present study is to evaluate nutritional status of patients admitted to pediatric intensive care units (PICU) in Turkey, examine the effect of nutrition on the treatment process and draw attention to the need for regulating nutritional support of patients while continuing existing therapies.Material and MethodIn this prospective multicenter study, the data was collected over a period of one month from PICUs participating in the PICU Nutrition Study Group in Turkey. Anthropometric data of the patients, calorie intake, 90-day mortality, need for mechanical ventilation, length of hospital stay and length of stay in intensive care unit were recorded and the relationship between these parameters was examined.ResultsOf the 614 patients included in the study, malnutrition was detected in 45.4% of the patients. Enteral feeding was initiated in 40.6% (n = 249) of the patients at day one upon admission to the intensive care unit. In the first 48 h, 86.82% (n = 533) of the patients achieved the target calorie intake, and 81.65% (n = 307) of the 376 patients remaining in the intensive care unit achieved the target calorie intake at the end of one week. The risk of mortality decreased with increasing upper mid-arm circumference and triceps skin fold thickness Z-score (OR = 0.871/0.894; p = 0.027/0.024). The risk of mortality was 2.723 times higher in patients who did not achieve the target calorie intake at first 48 h (p = 0.006) and the risk was 3.829 times higher in patients who did not achieve the target calorie intake at the end of one week (p = 0.001). The risk of mortality decreased with increasing triceps skin fold thickness Z-score (OR = 0.894; p = 0.024).ConclusionTimely and appropriate nutritional support in critically ill patients favorably affects the clinical course. The results of the present study suggest that mortality rate is higher in patients who fail to achieve the target calorie intake at first 48 h and day seven of admission to the intensive care unit. The risk of mortality decreases with increasing triceps skin fold thickness Z-score

Molecular Modifications of the Pseudomonas Quinolone Signal in the Intermicrobial Competition with Aspergillus

The Pseudomonas quinolone signal (PQS) is an important quorum-sensing molecule for Pseudomonas aeruginosa that regulates virulence factors, chelates iron, and is an important factor in interactions with eukaryotes, including fungi and mammalian hosts. It was previously shown to inhibit or boost Aspergillus, depending on the milieu iron concentration. We studied several molecular modifications of the PQS molecule, and their effects on Aspergillus biofilm metabolism and growth in vitro, and the effects of iron supplementation. We found that most molecules inhibited Aspergillus at concentrations similar to that of PQS, but with relatively flat dose-responses, and all were less potent than PQS. The inhibition was reversible by iron, suggesting interference with fungal iron metabolism. Stimulation of Aspergillus was not noted. We conclude that the critical Aspergillus-inhibiting moeities of the PQS molecule were partially, but not completely, interfered with by molecular modifications at several sites on the PQS molecule. The mechanism, as with PQS, appears to relate to fungal iron metabolism

Investigation of plasmid-mediated quinolone resistance among isolates obtained in a Turkish intensive care unit

The aim of this study was to search for three plasmid-encoded, quinolone-resistance determinants: qnrA, qnrB, and qnrS. Thus, 460 Gram-negative strains belonging to 11 different genera (clinical, 347; non-clinical, i.e., from a rectal swab, 113), of which 40% were ciprofloxacin-resistant, were recovered from patients in an intensive care unit at the Istanbul Medical Faculty, Turkey, in the years 2000 and 2006. PCR with primers specific for qnrA, qnrB, and qnrS genes and primers specific for a series of ESBL genes were used. One qnrB1 and two qnrS1 genes were identified in three ESBL-positive isolates, whereas no qnrA-positive strain was found. The qnrB1 determinant was identified in a ciprofloxacin-susceptible Enterobacter cloacae isolate that expressed CTX-M-15 beta-lactamase. Two qnrS1-determinants were found in two ciprofloxacin-susceptible E. cloacae isolates that were clonally related, but that had been isolated from different patients; both of these isolates expressed the same ESBL, CTX-M-3. This study detected the first plasmid-mediated quinolone-resistance determinants qnrB1 and qnrS1, among clinical strains obtained from patients in Turkey

Verapamil Inhibits Aspergillus Biofilm, but Antagonizes Voriconazole

The paucity of effective antifungals against Aspergillus and increasing resistance, the recognition of the importance of Aspergillus biofilm in several clinical settings, and reports of verapamil-a calcium channel blocker-efficacy against Candida biofilm and hyphal growth, and synergy with an azole antifungal in vitro, led to a study of verapamil +/- voriconazole against Aspergillus. Broth macrodilution methodology was utilized for MIC (minimum inhibitory concentration) and MFC (minimum fungicidal concentration) determination. The metabolic effects (assessed by XTT [2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide inner salt]) on biofilm formation by conidia were studied upon exposure to verapamil, verapamil plus voriconazole, or voriconazole alone. For biofilm formation, we found less inhibition from the combinations than with either drug alone, or less inhibition from the combination than that of the more potent drug alone. For preformed biofilm, we found no significant change in activity comparing voriconazole alone compared to added verapamil, and no significant alteration of activity of the more potent voriconazole, at any concentration in the range tested, by addition of a concentration of verapamil that is inhibitory alone. In full checkerboard assays with planktonic fungus, there was no indication of any effect of one drug on the other (indifference). Although verapamil was similarly inactive against planktonic Aspergillus, as with Candida, verapamil was indeed active against Aspergillus biofilm. However, indifference and antagonism was found with voriconazole