Enhancing anaerobic digestion of automotive paint sludge through biochar addition

The reduction of traditional fuel sources and the unpredictability of the global economy have led to a push for renewable energy alternatives. Waste recycling can significantly reduce greenhouse gas emissions. In this study, the effects of different proportions of biochar on the efficiency of mesophilic anaerobic digestion of automotive paint sludge were investigated over a period of one month. A combination of paint sludge and anaerobic sludge in a ratio of three to one was used, and biochar was added to the anaerobic digestion reactor in two different amounts of 10 and 26 g/l, with a control sample without biochar. The cumulative volume of biogas produced at the end of the one-month experiment was recorded for three samples: the control sample (without biochar), the second sample (with 2 g of biochar), and the third sample (with 5.2 g of biochar). The volumes of biogas produced were 300, 380, and 530 ml, respectively. Additionally, the COD reduction rates were 25%, 33%, and 48%, and the VS decrement rates were 21%, 27%, and 43%, respectively. The findings showed that adding biochar to the anaerobic digestion reactor containing automotive paint sludge increased biogas production. Additionally, gas chromatography results for an optimal sample of biogas extracted from the anaerobic digestion reactor indicated the presence of about 50% methane gas. These results highlight the potential for utilizing biochar in anaerobic digestion processes to improve renewable energy production and waste management.

Intelligent modeling of hydrogen sulfide solubility in various types of single and multicomponent solvents

This study aims to study the solubility of acid gas, i.e., hydrogen sulfide (H₂S) in different solvents. Three intelligent approaches, including Multilayer Perceptron (MLP), Gaussian Process Regression (GPR) and Radial Basis Function (RBF) were used to construct reliable models based on an extensive databank comprising 5148 measured samples from 54 published sources. The analyzed data cover 95 single and multicomponent solvents such as amines, ionic liquids, electrolytes, organics, etc., in broad pressure and temperature ranges. The proposed models require just three simple input variables, i.e., pressure, temperature and the equivalent molecular weight of solvent to determine the solubility. A competitive examination of the novel models implied that the GPR-based one gives the most appropriate estimations with excellent AARE, R² and RRMSE values of 4.73%, 99.75% and 4.83%, respectively for the tested data. The mentioned intelligent model also performed well in describing the physical behaviors of H₂S solubility at various operating conditions. Furthermore, analyzing the William's plot for the GPR-based model affirmed the high reliability of the analyzed databank, as the outlying data points comprise just 2.04% of entire data. In contrast to the literature models, the newly presented approaches proved to be applicable for different types of single and multicomponent H₂S absorbers with AAREs less than 7%. Eventually, a sensitivity analysis based on the GPR model reflected the fact that the solvent equivalent molecular weight is the most influential factor in controlling H₂S solubility.

A Review on Biomedical Application of Polysaccharide-Based Hydrogels with a Focus on Drug Delivery Systems

Over the last years of research on drug delivery systems (DDSs), natural polymer-based hydrogels have shown many scientific advances due to their intrinsic properties and a wide variety of potential applications. While drug efficacy and cytotoxicity play a key role, adopting a proper DDS is crucial to preserve the drug along the route of administration and possess desired therapeutic effect at the targeted site. Thus, drug delivery technology can be used to overcome the difficulties of maintaining drugs at a physiologically related serum concentration for prolonged periods. Due to their outstanding biocompatibility, polysaccharides have been thoroughly researched as a biological material for DDS advancement. To formulate a modified DDS, polysaccharides can cross-link with different molecules, resulting in hydrogels. According to our recent findings, targeted drug delivery at a certain spot occurs due to external stimulation such as temperature, pH, glucose, or light. As an adjustable biomedical device, the hydrogel has tremendous potential for nanotech applications in involved health areas such as pharmaceutical and biomedical engineering. An overview of hydrogel characteristics and functionalities is provided in this review. We focus on discussing the various kinds of hydrogel-based systems on their potential for effectively delivering drugs that are made of polysaccharides.

P-303 Supplementing IVM medium with mesenchymal stem cell-conditioned medium, L-carnitine, and Repaglinide to improve maturation and developmental competence of oocytes derived from normal and endometriosis mice

Study question

Does supplementing in vitro maturation (IVM) medium with bone marrow mesenchymal stem cell-conditioned medium (BMSC-CM), L-carnitine (LC), and Repaglinide (RG) enhance the developmental competence of oocytes derived from endometriosis-induced mice?

Summary answer

L-carnitine and BMSC-CM supplementation improved maturation and fertilization, and developmental competence of oocytes following IVF by modulating nitro-oxidative stress and accelerating nuclear maturation of oocytes.

What is known already

Endometriosis (EMS) is a detrimental condition of the female reproductive system affecting up to 15% of women of reproductive age. Oocytes retrieved from EMS-affected ovaries are more likely to fail IVM and to show altered morphology and lower cytoplasmic mitochondrial content. Mesenchymal stem cells (MSCs) secrete various types of cytokines, growth factors, bioactive factors, and tissue regenerative components into mesenchymal stem cell-conditioned medium. L-carnitine is an antioxidant playing an important role in cell metabolism and is crucial for fatty acid metabolism. Repaglinide (RG) is an anti-hyperglycemic medication that induces insulin secretion by attaching to β cells of the pancreas.

Study design, size, duration

To induce EMS, two groups of mice were used. The first group, as donor mice, were intraperitoneally injected with estradiol-17β depot for one week. Then, they were sacrificed on day 14, and their uterine horns were removed. The suspension including tissue fragments from uterine horns was injected intraperitoneally to the recipient mice group. To ensure the induction of EMS, ovaries of some mice in both normal and EMS groups were analyzed by histological examination.

Participants/materials, setting, methods

Adult female NMRI mice (6-8 weeks old) were divided into two normal and EMS-induced mice. Oocytes obtained from normal and EMS-induced mice were cultured in the IVM medium supplemented with RG, LC, and BMSC-CM for 24 hours. Subsequently, IVM, IVF, embryo development rates, blastocyst cell numbers were assessed. Moreover, the levels of reactive oxygen species (ROS), nitric oxide (NO), and total antioxidant capacity (TAC) of the IVM medium were evaluated.

Main results and the role of chance

Microscopic studies of ovarian tissue samples showed that folliculogenesis, quality of follicles, and oocyte quality reduced in the EMS-induced group. The IVM results represent that 0.3 mg/ml and 0.6 mg/ml of LC, and 25% and 50% of BMSC-CM enhanced the percentage of MII oocytes significantly. Indeed, the highest IVM rate in both the normal and EMS-induced mice was observed in the BMSC-CM 50% group. More importantly, 0.3 and 0.6 mg/ml of LC, and 25% and 50% of BMSC-CM treatments showed a dramatic decrease in ROS and NO levels and a significant enhancement in TAC levels compared to the control group. Our results also indicated that there was a substantial improvement in terms of IVF, cleavage, and blastocyst rates in all treatment groups compared to the control group. The highest blastocyst formation rate was obtained in 50% of the BMSC-CM group. In normal groups, there was a dramatic increase in the mean of total cell number and TE cells in 1µM RG, 0.3 and 0.6 mg/ml LC, 25% and 50% BMSC-CM. In EMS-induced groups, except for the 1M RG group, all treatment groups exhibited a significant difference in the mean total cell population and TE cells compared to the control group.

Limitations, reasons for caution

Due to limited laboratory facilities, the levels of growth factors, pro-inflammatory cytokines, anti-apoptotic, and antioxidants were not measured in the IVM medium. We, therefore, do not know which of the constituents of the BMSC-CM, in particular, had promoter effects on the oocyte maturation, fertilization, and developmental competence of IVF embryos.

Wider implications of the findings

These approaches may outline the clinical applications of LC and BMSC-CM in the assisted reproductive technology (ART) setting and pave the way to improve the maturation culture. Also, these findings can advance the efficiency of fertility outcomes in endometriosis-related infertile couples.

Trial registration number

N/A

O-185 Cryopreservation of Human Spermatozoa: Utilization of L-Proline as a Novel Additive to Improve Sperm Quality Following Freezing-Thawing Process

Study question

Does supplementation of human sperm freezing media with L-Proline improve sperm quality and DNA Integrity following the freezing-thawing process?

Summary answer

The inclusion of L-proline as a novel additive to human sperm cryopreservation media improves sperm parameters and DNA integrity via mitigating oxidative stress.

What is known already

Sperm cryopreservation is an essential aspect of assisted reproductive technique (ART) and male fertility preservation. Although frozen-thawed semen has great practical benefits for reproduction, it is widely reported that the cryopreservation process induces physical and chemical detrimental changes in sperm functions. Indeed, freezing induces nitro-oxidative stress, lipid peroxidation, DNA fragmentation, and apoptosis. L-proline plays versatile roles in osmotic protection and oxidative stress, cell signaling, programmed cell death, and nutrient adaptation. This multifunctional amino acid is a natural osmoprotectant and the protective effect of L-proline against freezing-thawing-induced damages in stallion and donkey spermatozoa have been reported.

Study design, size, duration

Thirty normozoospermic semen samples were collected by masturbation after 3–5 days of sexual abstinence from men who were referred to the IVF clinic of Kermanshah Motazedi Hospital from December 2020 to June 2021. Each prepared semen sample was aliquoted to 4. In aliquots 1 to 4, experimental concentrations of L-proline (0, 1, 2, and 4 mmol/L), were included in the freezing medium.

Participants/materials, setting, methods

30 normozoospermic, healthy, non-smoker men were enrolled. Sperm parameters (progressive motility, viability, and morphology) were assessed. Sperm chromatin quality was measured by Aniline blue (AB), Toluidine blue (TB), and Chromomycin A3 (CMA3) staining. DNA integrity was evaluated by the Sperm chromatin dispersion (SCD) test. Furthermore, the levels of reactive oxygen species (ROS), lipid peroxidation (LPO), and total antioxidant capacity (TAC) were determined in sperm freezing media. All assessments were conducted before cryopreservation and after thawing.

Main results and the role of chance

Our findings showed that sperm progressive motility and viability were significantly higher in the 4 mmol/L L-proline treated groups compared to the control groups (p = 0.003, p = 0.0200) respectively. The percentage of normal morphology was improved in L-Proline-treated groups. However, this improvement was not considerable (p > 0.5). Moreover, the level of ROS production significantly diminished in the 4 mmol/L L-proline group compared to the control group (p < 0.001). Besides, the level of TAC was significantly enhanced in the 4 mmol/L L-proline group by comparison to the control group (p < 0.001). Furthermore, the results of AB and TB tests demonstrated that chromatin packaging after supplementation with 4 mmol/L L-proline significantly improved compared to the control group (p < .0001). In this regard, there was a significant improvement between the 4 mmol/L   L-proline group and the control group in terms of CMA3 evaluation (p < .0001). Also, there was a difference between the 4 mmol/L L-proline group and the control group in reducing the level of fragmented DNA. Although 4 mmol/L of Praline could diminish the SCD level compared to the control group, this amelioration was not statically significant (p = 0.053).

Limitations, reasons for caution

We were not able to perform further studies to verify the effects of L-proline on mitochondrial activity and membrane potential, and sperm apoptosis as well as to confirm the efficiency and safety of L-proline in terms of more indicators such as the in vitro embryonic development and live birth rate.

Wider implications of the findings

These findings can draw attention to the potential role of L-proline as a novel additive and antioxidant to human freezing medium in preserving sperm quality and protecting spermatozoa against ROS attack during sperm cryopreservation in infertility clinics.

Trial registration number

N/A

In vitro maturation medium supplementation: utilization of repaglinide, L-carnitine, and mesenchymal stem cell-conditioned medium to improve developmental competence of oocytes derived from endometriosis mouse models

Endometriosis (EMS) is one of the most prevalent causes for female infertility. Herein, we investigated the effect of the repaglinide (RG), L-carnitine (LC), and bone marrow mesenchymal stem cell-conditioned medium (BMSC-CM) supplementation during in vitro maturation (IVM) on the quality, maturation, and fertilization rates, as well as embryonic quality and development of oocytes derived from normal and EMS mouse model. Immature oocytes were collected from two groups of normal and EMS-induced female NMRI mice at 6-8 weeks of age. Oocytes were cultured in IVM medium unsupplemented (control group), or supplemented with 1 M RG, 0.3 and 0.6 mg/mL LC, and 25 and 50% BMSC-CM. After 24 h of oocyte incubation, IVM rate and antioxidant status were assessed. Subsequently, the rates of fertilization, cleavage, blastulation, and embryonic development were assessed. Our results demonstrated that supplementation of IVM medium with LC and BMSC-CM, especially 50% BMSC-CM, significantly enhanced IVM and fertilization rates, and markedly improved blastocyst development and total blastocyst cell numbers in EMS-induced mice compared to the control group (53.28±0.24 vs 18.09±0.10%). Additionally, LC and BMSC-CM were able to significantly modulate EMS-induced nitro-oxidative stress by boosting total antioxidant capacity (TAC) and mitigating nitric oxide (NO) levels. Collectively, LC and BMSC-CM supplementation improved oocyte quality and IVM rates, pre-implantation developmental competence of oocytes after in vitro fertilization, and enhanced total blastocyst cell numbers probably by attenuating nitro-oxidative stress and accelerating nuclear maturation of oocytes. These outcomes may provide novel approaches to refining the IVM conditions that can advance the efficiency of assisted reproductive technologies in infertile couples.

The application of the loop-mediated isothermal amplification method for rapid detection of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is an important problem associated with significant mortality and morbidity and well known as a predominant bacterial pathogen. The aim of this study was to identify MRSA strains. In this study (June 2018 to June 2019) isolates of S. aureus were obtained from patients referred to teaching hospitals of Ahvaz, Iran. All isolates were confirmed by conventional microbiological methods. In following, antimicrobial susceptibility testing (AST), MRSA screening, PCR detection of MRSA and LAMP assay were performed. Out of a total of 156 staphylococcal isolates, 126 isolates were identified as MRSA. Seventy-two (57.1%) MRSA isolates were recovered from wound. All MRSA isolates were sensitive to vancomycin, linezolid, teicoplanin, quinupristin-dalfopristin, and tigecycline. The results of LAMP showed 100% agreement with PCR. Sensitivity and specificity of the LAMP assays for the mecA genes were 100% and 100%, respectively. The LAMP assay is a rapid and simple method for the identifications of MRSA. Because of its performance without the need for specific instrumentation, this method can be easily employed in medical centers for the detection of mecA.

Investigation on factors associated with ovarian cancer: an umbrella review of systematic review and meta-analyses

Following cervical and uterine cancer, ovarian cancer (OC) has the third rank in gynecologic cancers. It often remains non-diagnosed until it spreads throughout the pelvis and abdomen. Identification of the most effective risk factors can help take prevention measures concerning OC. Therefore, the presented review aims to summarize the available studies on OC risk factors. A comprehensive systematic literature search was performed to identify all published systematic reviews and meta-analysis on associated factors with ovarian cancer. Web of Science, Cochrane Library databases, and Google Scholar were searched up to 17th January 2020. This study was performed according to Smith et al. methodology for conducting a systematic review of systematic reviews. Twenty-eight thousand sixty-two papers were initially retrieved from the electronic databases, among which 20,104 studies were screened. Two hundred seventy-seven articles met our inclusion criteria, 226 of which included in the meta-analysis. Most commonly reported genetic factors were MTHFR C677T (OR=1.077; 95 % CI (1.032, 1.124); P-value<0.001), BSML rs1544410 (OR=1.078; 95 %CI (1.024, 1.153); P-value=0.004), and Fokl rs2228570 (OR=1.123; 95 % CI (1.089, 1.157); P-value<0.001), which were significantly associated with increasing risk of ovarian cancer. Among the other factors, coffee intake (OR=1.106; 95 % CI (1.009, 1.211); P-value=0.030), hormone therapy (RR=1.057; 95 % CI (1.030, 1.400); P-value<0.001), hysterectomy (OR=0.863; 95 % CI (0.745, 0.999); P-value=0.049), and breast feeding (OR=0.719, 95 % CI (0.679, 0.762) and P-value<0.001) were mostly reported in studies. Among nutritional factors, coffee, egg, and fat intake significantly increase the risk of ovarian cancer. Estrogen, estrogen-progesterone, and overall hormone therapies also are related to the higher incidence of ovarian cancer. Some diseases, such as diabetes, endometriosis, and polycystic ovarian syndrome, as well as several genetic polymorphisms, cause a significant increase in ovarian cancer occurrence. Moreover, other factors, for instance, obesity, overweight, smoking, and perineal talc use, significantly increase the risk of ovarian cancer.

Moderate overfeeding of different sources of metabolizable energy and protein. II: Effects on inflammatory status of sheep in late pregnancy and growth trajectory of the offspring

Our objective was to evaluate the effects of moderate overfeeding of different sources of metabolizable energy (ME) and protein (MP) on inflammatory status of sheep in late gestation and short-term growth performance of the offspring. A total of 32 healthy pregnant Zell ewes (2.5 ± 1 years old, 42.19 ± 1.65 kg body weight [BW]) were selected 7 weeks before lambing. After receiving a ten-day adaptation diet, eight ewes were randomly allocated to each of the four treatments including: 1) The adaptation diet that fulfills ME and MP requirements, according to the National Research Council's (NRC, 2007) recommendations for late pregnant ewes (CON); 2) A diet with 10% higher levels of ME than CON, using corn grain for extra ME (HEC); 3) A diet with 10% higher level of ME compared to CON, using flaxseed for additional ME (HEF); and 4) A diet with a 10% higher level of MP than CON, using a rumen-protected lysin and methionine supplement (RP-Lys & Met) to supply extra MP (PRO). After lambing, ewes continued their dietary treatments until 30 days postpartum; however, the content of ingredients were proportionally increased to meet the recommended levels of energy and protein for lactating ewes (NRC, 2007). Blood samples from the ewes were taken on days -21, -14, and -7 before parturition. Colostrum yield and components were determined, and lamb's BW and milk intake (MI) were measured weekly until 28 days of age. Other growth performance indexes were computed accordingly. Blood samples from the offspring were taken on days 15 and 30 of life. The data was analyzed using SAS software (SAS Institute Inc., 9.4). Compared with the CON, HEF-fed ewes were the only group that had lower levels of oxidative stress and blood inflammatory markers at -7 d before parturition (P < 0.05). Concentrations of aminotransferases in CON-fed ewes were greater than other groups in late gestation (P ≤ 0.05). Offspring of HEF- and PRO-fed ewes had higher birth BW than lambs of the CON-fed group (3.71 and 4.11 vs. 3.01 ± 0.24, Kg for HEF, PRO, and CON, respectively). Except for week 2, lambs of CON-fed ewes had lower BW gain compared with the other offspring (P < 0.01). Lambs of PRO-fed ewes had greater levels of plasma immunoglobulin G (IgG, days 15 and 30 of life; P < 0.05) and MI (from week 2; P < 0.001) than other groups. In conclusion, regardless of the source, moderate overfeeding of ME/MP was more beneficial for the immune status of late pregnant dams and the offspring's performance than non-overfed ones.

P–061 Protective effect of melatonin against bleomycin, etoposide, and cisplatin (BEP) chemotherapy-induced testicular toxicity in Wistar rats: A biochemical, immunohistochemical and apoptotic genes based evidence

Study question

Does exogenous melatonin (MLT) attenuate BEP-induced damage in testicular cells and spermatogenesis in a dose-dependent manner?

Summary answer

Melatonin protected the testes against BEP-induced testis damage through ameliorating nitro-oxidative stress, apoptosis, and inflammation. However, there was no significant difference between melatonin-treated groups.

What is known already

Recently, the prevalence of testicular cancer (TC), accounting for the most common cancer among young people of reproductive age (15–40 years), has risen internationally. BEP chemotherapy has increased the 5-year survival rate of TC patients at all stages of testicular germ cell tumors to 90–95%. However, BEP creates a high incidence of male infertility and even long-term genotoxic effects, which emerges as a critical health issue. Melatonin is a well-known potent antioxidant with widespread clinical applications that recently has been giving increasing attention to its role in male sub/infertility.

Study design, size, duration

60 Adult male Wistar rats were randomly assigned to six groups (n = 10/group). Group 1, 3, and 4 were injected with vehicle, 10 and 20 mg/kg of melatonin, respectively. Other groups received one cycle of bleomycin, etoposide, and cisplatin for a total of 3 weeks with or without melatonin. Melatonin administration started daily one week before BEP initiation continued on days 2, 9, and 16; and one week after the completion of the BEP cycle.

Participants/materials, setting, methods

Bodyweight, testes weight, Sperm parameters (count, motility, viability, and morphology), testosterone hormone level, testicular histopathology, stereological parameters, testicular level of malondialdehyde (MDA), nitric oxide (NO), and total antioxidant capacity (TAC), the expression of Bcl–2, Bax, Caspase–3, p53, and TNF-α (Real-time PCR and immunohistochemistry) were evaluated at the end of the study (day 35).

Main results and the role of chance

Our findings showed that melatonin restores the BEP-induced reduction in the body and testes weight (P&lt;.05). the evaluation of quantitative analysis of the testes stereological procedures, QRT-PCR examination and immunohistochemical (IHC) staining revealed that melatonin reverses the BEP-induced impaired spermatogenesis (P&lt;.05). Furthermore, melatonin rectifies BEP-induced disturbance on sperm count, motility, viability, and morphology. The testosterone level in the BEP-treated group was decreased significantly by comparison with the control group (P&lt;.01). By contrast, co-administration of 10 and 20 mg/kg of melatonin could enhance the serum testosterone level significantly (P&lt;.05). Moreover, melatonin enhanced the antioxidant status of the testis by elevating TAC and ameliorating MDA and NO levels. More notably, QRT-PCR examination indicated that melatonin therapy suppressed BEP-induced apoptosis by modulating apoptosis-associated genes such as Bcl–2, Bax, Caspase–3, p53 in the testis (P&lt;.01). Besides, Co-administration of 10 and 20 mg/kg of melatonin with BEP regimen decreased significantly the population of p53 (54.21 ±6.18% and 51.83±8.45, respectively) and TNF-α positive cells (42.91±9.92% and 33.57±2.97, respectively) by comparison to the BEP group. Also, melatonin with low and high doses could enhance the expression of Bcl–2 protein in spermatogenic cells line (59.19±10.18%, 63.08±5.23, respectively) compared to the BEP-treated group.

Limitations, reasons for caution

Owing to limited laboratory facilities we were not able to perform further studies to verify the mechanism of melatonin in the specific targets by using transfection technique and transgenic.

Wider implications of the findings: These findings can draw attention to the clinical application of melatonin and also suggest that melatonin may be an attractive agent for attenuating chemotherapy-associated male sub/infertility. This indolamine also may shorten the fertility recovery period in patients undergoing chemotherapy with the BEP regimen.

Trial registration number

N/A

Investigating the anti-inflammatory effects of high molecular weight secretions from Limosilactobacillus reuteri PTCC 1655 on LPS-stimulated PMA-differentiated THP-1 cells

AIMS

This study was done to investigate the anti-inflammatory effects of high molecular weight secretions from Limosilactobacillus reuteri PTCC 1655 probiotic bacteria on lipopolysaccharide (LPS)-stimulated phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells.

METHODS AND RESULTS

After culturing the bacterium, the crude cell-free supernatant was fractionated on the basis of molecular weights using ultrafiltration. Also, a heat-killed and sonicated fraction was obtained from the biomass of the bacterial culture. All fractions were used to measure their anti-inflammatory effects on PMA-differentiated THP-1 cells following LPS stimulation by quantifying various cellular markers of inflammation. The results demonstrated that various L. reuteri PTCC 1655-derived fractions, especially the >100 kDa supernatant fraction decreased some of the inflammatory cytokines and mediators, including tumour necrosis factor-α, interleukin-1, nitric oxide, cyclooxygenase-2, matrix metalloproteinase-9 and interleukin-6, which are critical for the pathogenesis of some inflammatory diseases.

CONCLUSION

It is concluded that the L. reuteri PTCC 1655-derived high molecular weight fractions significantly reduce inflammation and therefore could be appropriate candidates for future medical studies.

SIGNIFICANCE AND IMPACT OF THE STUDY

Providing new insights about the significance of L. reuteri PTCC 1655-derived extracts and their potential to modulate inflammation.

Moderate over-feeding of different sources of metabolizable energy and protein improved gestational insulin resistance markers and maternal metabolic status of sheep around lambing

The objective of this study was to determine the effect of moderate over-nutrition of energy (using flaxseed as a source of n-3 fatty acids) and protein (using rumen-protected lysine and methionine) around parturition on prepartal insulin resistance (IR) and periparturient metabolic status and performance of ewes. For this purpose, 32 apparently healthy ewes (2.5 ± 1 years old, 42.19 ± 1.65 kg body weight (BW)) were randomly selected out of 200 pregnant Zell ewes on d 50 before the expected lambing. After receiving a ten-day adaptation diet, eight ewes were randomly allocated to one of the following four dietary treatments: 1) the adaptation diet that meets the metabolizable energy (ME) and protein (MP) requirements of ewes during late pregnancy as recommended by National Research Council = NRC (2007) (Control = CON). 2) A diet with 10% higher levels of ME than NRC (2007) recommendations using corn grain as a source of extra ME (HEC). 3) A diet with 10% higher levels of ME compared to NRC (2007) recommendations using flaxseed for additional ME (HEF). 4) A diet with a 10% higher level of MP than NRC (2007) recommendations using rumen-protected lysine and methionine as a source of extra MP (PRO). While the dietary treatments did not affect animals' dry matter intake (DMI), the CON ewes lost more BW starting from d 10 to d 30 relative to parturition compared to others (P < 0.05). Milk protein and fat yield (g/d) were significantly higher for PRO and HEF compared to HEC and CON ewes (P < 0.05). Moderately over-fed ewes with MP and ME had an improved insulin sensitivity (IS) compared to CON ones. The source of additional ME also impacted IR indices because HEC showed an enhancement in IS than HEF animals (P < 0.05). A lower IS in CON ewes was parallel with higher concentrations of plasma urea at prepartum (P < 0.01), lower levels of plasma cholesterol, triglyceride (P < 0.01) and glucose post-partum (P < 0.05), and a tendency for higher levels of beta-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFA) in CON ewes during both pre- and post-partum periods. There were negative correlations between plasma urea, BHB, and NEFA with IR markers on d 7 prepartum in line with these results. Comparing data, we could not find a significant change in metabolic status among ewes fed with either PRO or HEF/HEC. In conclusion, the inclusion of 10% extra MP and ME could improve late gestation maternal IS and the metabolic status of dams around lambing.

Evaluating the frequency of carbapenem and aminoglycoside resistance genes among clinical isolates of Acinetobacter baumannii from Ahvaz, south-west Iran

Acinetobacter baumannii is one of the most important opportunistic challenging pathogens as a result of its ability to acquire resistance to broad range of antibiotics and cause a variety of severe nosocomial infections. We investigated the frequency of the aminoglycoside-modifying enzymes (AMEs) and oxacillinase genes among clinical isolates of A. baumannii collected from hospitalized patients in Imam Khomeini Hospital, Ahvaz city, Iran. This prospective cross-sectional study was performed on 80 clinical isolates of A. baumannii collected from patients referred to Imam Khomeini Hospital in Ahvaz, Iran. Initial identification of isolates as A. baumannii was performed using conventional bacteriologic tests, and final confirmation was carried out by PCR of bla_OXA-51-like gene and multiplex PCR of gyrB locus. MICs of different classes of antibiotics against these strains was measured by using VITEK 2 system. After extraction of genomic DNA, two groups of multidrug-resistant A. baumannii genes including AME (aadA1, aadB, aphA6 and aacC1) and oxacillinases (bla_OXA-23-like, bla_OXA-24-like, bla_OXA-51-like, bla_OXA-58-like and bla_OXA-143-like) were detected. According to antibiotic susceptibility testing, among 80 A. baumannii strains, 75 isolates (91.25%) were multidrug resistant. The results showed that colistin and tigecycline, with respective sensitivity rates of 97.5% (78/80) and 56.25% (45/80), had the highest effects. The presence of bla_OXA-51-like and gyrB genes was confirmed in all strains. Furthermore, bla_OXA-23-like and bla_OXA-24-like genes were found in 68.75% (55/80) and 20% (16/80) of isolates respectively, while no isolate harbored the bla_OXA-143-like gene. The frequency of genes encoding the AMEs including aadA1, aacC1, aphA6 and aadB were 11.25% (9/80), 16.25% (13/80), 22.5% (18/80) and 30% (24/80) respectively. Our findings indicate that the presence of the aadB and aphA6 is correlated with high resistance against amikacin and gentamicin. We found a very high resistance rate against most of the antimicrobial agents usually prescribed for severe infections caused by A. baumannii. Therefore, because of rapid emergence of resistance even for colistin or tigecycline, monotherapy should be avoided. These results show the importance of providing antibiotics correctly in intensive care units and following antibiotic stewardship protocols as the only effective strategies to attempt to control antibiotic resistance in healthcare settings.

Chlorhexidine alcohol versus povidone-iodine: The comparative study of skin disinfectants at the blood transfusion centers of Iran

OBJECTIVES

The skin disinfection in the blood donor's arm is a key step to minimize the risk of microbial contamination at blood donation sessions. Current study aimed to compare the efficacy of 2% chlorhexidine gluconate in 70% isopropyl alcohol (CHG/IPA) with povidone-Iodine (PI) at blood transfusion centers (BTCs) of Iran.

MATERIAL AND METHODS

Blood donors were selected to evaluate three commercial CHG/IPA disinfectants (N=300), prior the application at BTCs, and to compare the rate of positive skin cultures between CHG/IPA and PI in 31 BTCs (N=8578). The rate of positivity for PI over a 5-year period was also investigated. After application of a two-step disinfection procedure, the biochemical characteristics were checked in accordance with the conventional bacteriological methods. The Z-test analysis was used to compare the deviation between the positive microbial culture ratios.

RESULT

No donors had a positive culture after disinfection during the evaluation study. There was no difference in the rate of positivity between PI and CHG/IPA after disinfection (P>0.05). The rate of positivity for PI from 2012 to 2017 showed a decreasing trend. The rate of positivity was significantly higher in winter rather than summer (P<0.05).

CONCLUSION

The disinfection efficacy of CHG/IPA was equivalent to that of PI. The 5-year monitoring of PI at BTCs showed that the improvement in the rate of positive skin cultures possibly due to effectiveness of correcting actions.

Alterations in brainstem auditory processing, the acoustic startle response and sensorimotor gating of startle in Wistar audiogenic rats (WAR), an animal model of reflex epilepsies

While acute audiogenic seizures in response to acoustic stimulus appear as an alteration in sensory-motor processing in the brainstem, the repetition of the stimulus leads to the spread of epileptic activity to limbic structures. Here, we investigated whether animals of the Wistar Audiogenic Rat (WAR) strain, genetically selected by inbreeding for seizure susceptibility, would have alterations in their auditory response, assessed by the auditory brainstem responses (ABR) and sensory-motor gating, measured as pre-pulse inhibition (PPI), which could be related to their audiogenic seizures susceptibility or severity. We did not find differences between the amplitudes and latencies of ABR waves in response to clicks for WARs when compared to Wistars. Auditory gain and symmetry between ears were also similar. However, hearing thresholds in response to some tones were lower and amplitudes of wave II were larger in WARs. WARs had smaller acoustic startle reflex amplitudes and the percentages of startle inhibited by an acoustic prepulse were higher for WARs than for Wistars. However, no correlation was found between these alterations and brainstem-dependent seizure severity or limbic seizure frequency during audiogenic kindling. Our data show that while WARs present moderate alterations in primary auditory processing, the sensory motor gating measured in startle/PPI tests appears to be more drastically altered. The observed changes might be correlated with audiogenic seizure susceptibility but not seizures severity.

Naloxone-precipitated withdrawal ameliorates impairment of cost-benefit decision making in morphine-treated rats: Involvement of BDNF, p-GSK3-β, and p-CREB in the amygdala

Several studies indicated that morphine administration impairs cognitive brain functions. Therefore, in the current study, we investigated the effect of subchronic exposure to morphine and its withdrawal on effort- and/or delay-based forms of cost-benefit decision making and alterations in p-CREB/CREB ratio, p-GSK3β/GSK3β ratio, and BDNF level during decision making in the amygdala. Our data displayed an impairment of both forms of cost-benefit decision making following subchronic exposure to morphine. However, preference of high reward/high effort and/or high delay reward increased after naloxone injection. In molecular section, levels of BDNF and p-CREB/CREB ratio increased during cost-benefit decision making while p-GSK3β/GSK3β ratio decreased in both forms of decision making. In morphine-treated rats, level of BDNF and p-CREB/CREB ratio reduced during both forms of decision making while p-GSK3β/GSK3β ratio increased during delay-based and did not have a significant difference with the control group during effort-based decision making. On the withdrawal day, BDNF level raised while p-GSK3β/GSK3β ratio attenuated compared to morphine-treated group in both form of decision making. In addition, p-CREB/CREB ratio increased only during delay-based decision making on the withdrawal day. In conclusion, our data revealed that subchronic exposure to morphine interferes with the cost-benefit decision making may be via changes in level of BDNF, p-CREB/CREB and p-GSK3β/GSK3β ratio in the amygdala.

Laccase production from sucrose by recombinant Yarrowia lipolytica and its application to decolorization of environmental pollutant dyes

Laccases are used in decolorization and biodegradation of synthetic dyes, bioremediation of industrial wastewaters and delignification of lignocellulosic compounds. The aims of the present study were the optimization of a recombinant laccase production in Yarrowia lipolytica yeast using sucrose as a main carbon source, and the application of the resulting enzyme to decolorization of synthetic dyes, which are problematic environmental pollutants. Taguchi's experimental design method was employed to optimize medium compounds. Recombinant laccase production by Y. lipolytica YL4 strain increased to 900 U L^-1 after optimization of sucrose, ammonium chloride, yeast extract and thiamine levels in the modified PPB medium. Furthermore, the production rate reached 6760 U L^-1 in a 5 L bioreactor which represents 4.5- and 33.5-fold increases compared to cultures that were in shake-flask with optimized and primary media, respectively. The supernatant containing secreted recombinant laccase was applied for decolorization of seven dyes. The effects of pH, the amount of enzyme and incubation period were verified. The effect of incubation time on dye decolorization by recombinant laccase was important, which has an influence of greater extent than 90% after 48 h for all dyes. The Trametes versicolor laccase can be efficiently produced in Y. lipolytica and the recombinant enzyme has a considerable potential in the decolorization of pollutant synthetic dyes.

Detection of acute Toxoplasma gondii infection in pregnant women by IgG avidity and PCR analysis

During pregnancy, Toxoplasma gondii can be transmitted from mother to foetus and trigger a primary infection that may be symptomatic. It is important to distinguish between recently acquired and past infections to ensure proper treatment to minimize irreversible foetal injury. We used PCR of the B1 gene to evaluate the accuracy of T. gondii IgG antibody avidity testing in discriminating recent from past infection. In a cross-sectional study, T. gondii IgG and IgM antibodies were detected by enzyme linked fluorescence assay (ELFA) in 2120 serum samples from pregnant women referred to Karaj medical laboratories, February 2013 through March 2015 with 40 samples found positive. IgM-positive samples were evaluated by IgG avidity testing and PCR to amplify the B1 gene. Avidity studies indicated 20 samples with high IgG avidity, 15 with low IgG avidity, and five showing borderline values. The B1 gene was amplified in the borderline samples, with nine of the 15 showing low avidity. The B1 gene was not amplified in the high avidity sera. Our findings suggest that IgG avidity alone may not be sufficient to discriminate recent from past T. gondii infection and should not be used as the sole confirmatory test in pregnant women with IgG and IgM T. gondii antibodies. IgG avidity testing in combination with PCR may be more reliable for distinguishing between high- and low-risk infection and decrease the frequency of unnecessary treatment of pregnant women.

Exposure to Visible Light Emitted from Smartphones and Tablets Increases the Proliferation of Staphylococcus aureus: Can this be Linked to Acne?

BACKGROUND

Due to rapid advances in modern technologies such as telecommunication technology, the world has witnessed an exponential growth in the use of digital handheld devices (e.g. smartphones and tablets). This drastic growth has resulted in increased global concerns about the safety of these devices. Smartphones, tablets, laptops, and other digital screens emit high levels of short-wavelength visible light (i.e. blue color region in the visible light spectrum).

MATERIAL AND METHODS

At a dark environment, Staphylococcus aureus bacteria were exposed to the light emitted from common tablets/smartphones. The control samples were exposed to the same intensity of light generated by a conventional incandescent light bulb. The growth rate of bacteria was examined by measuring the optical density (OD) at 625 nm by using a spectrophotometer before the light exposure and after 30 to 330 minutes of light exposure.

RESULTS

The growth rates of bacteria in both smartphone and tablet groups were higher than that of the control group and the maximum smartphone/control and tablet/control growth ratios were observed in samples exposed to digital screens' light for 300 min (ratios of 3.71 and 3.95, respectively).

CONCLUSION

To the best of our knowledge, this is the first study that investigates the effect of exposure to light emitted from digital screens on the proliferation of Staphylococcus aureus and its association with acne pathogenesis. Our findings show that exposure to short-wavelength visible light emitted from smartphones and tablets can increase the proliferation of Staphylococcus aureus.

Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli

Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

A label-free, PCR-free and signal-on electrochemical DNA biosensor for Leishmania major based on gold nanoleaves

Detection of leishmaniasis is important in clinical diagnoses. In the present study, identification of Leishmania parasites was performed by a label-free, PCR-free and signal-on ultrasensitive electrochemical DNA biosensor. Gold nanoleaves were firstly electrodeposited by an electrodeposition method using spermidine as a shape directing agent. The biosensor was fabricated by immobilization of a Leishmania major specific DNA probe onto gold nanoleaves, and methylene blue was employed as a marker. Hybridization of the complementary single stranded DNA sequence with the biosensor under the selected conditions was then investigated. The biosensor could detect a synthetic DNA target in a range of 1.0×10^-10 to 1.0×10^-19molL^-1 with a limit of detection of 1.8×10^-20molL^-1, and genomic DNA in a range of 0.5-20ngμL^-1 with a limit of detection of 0.07ngμL^-1. The biosensor could distinguish Leishmania major from a non-complementary-sequence oligonucleotide and the tropica species with a high selectivity. The biosensor was applicable to detect Leishmania major in patient samples.

Administration of activated glial condition medium in the nucleus accumbens extended extinction and intensified reinstatement of methamphetamine-induced conditioned place preference

Methamphetamine (METH) is a psychostimulant drug with significant abuse potential and neurotoxic effects. A high percentage of users relapse to use after detoxification and no effective medication has been developed for treatment of METH addiction. Developing evidences indicated the role of glial cells in drugs abused related phenomena. However, little is known about the role of these cells in the maintenance and reinstatement of METH-seeking behaviors. Therefore, the current study was conducted to clarify the role of glial cells in the maintenance and reinstatement of METH-induced conditioned place preference (CPP) in rats. Astrocyte condition medium (ACM) and neuroglia conditioned medium (NCM) are liquid mediums prepared from primary astrocyte and neuroglia cells. These mediums seem to contain many factors that release by glia cells. CPP was induced by systemic administration of METH (1mg/kg for 5days, s.c.). Following the establishment of CPP, the rats were given daily bilateral injections (0.5μl/side) of either vehicle, ACM or NCM into the nucleus accumbens (NAc) and then were tested for the maintenance and reinstatement. Intra-NAc administration of ACM treated with METH, could extend the extinction period and also, intensified the magnitude of METH reinstatement. Furthermore, intra-accumbal administration of NCM treated with METH notably delayed the extinction period by four days and significantly increased the magnitude of CPP score in the reinstatement phase compared to the post-test phase. Collectively, these findings suggested that activation of glial cells may be involved in the maintenance and reinstatement of METH-seeking behaviors. It provides new evidence that glia cells might be considered as a potential target for the treatment of METH addiction.

Progression-free and overall survival in ovarian cancer patients treated with CVac, a mucin 1 dendritic cell therapy in a randomized phase 2 trial

Background

CAN-003 was a randomized, open-label, Phase 2 trial evaluating the safety, efficacy and immune outcomes of CVac, a mucin 1 targeted-dendritic cell (DC) treatment as a maintenance therapy to patients with epithelial ovarian cancer (EOC).

Methods

Patients (n = 56) in first (CR1) or second clinical remission (CR2) were randomized (1:1) to standard of care (SOC) observation or CVac maintenance treatment. Ten doses were administered over 56 weeks. Both groups were followed for progression-free survival (PFS) and overall survival (OS).

Results

Fifty-six patients were randomized: 27 to SOC and 29 to CVac. Therapy was safe with only seven patients with Grade 3–4 treatment-emergent adverse events. A variable but measurable mucin 1 T cell-specific response was induced in all CVac-treated and some standard of care (SOC) patients. Progression free survival (PFS) was not significantly longer in the treated group compared to SOC group (13 vs. 9 months, p = 0.36, hazard ratio [HR] = 0.73). Analysis by remission status showed in the CR1 subgroup a median PFS of 18 months (SOC) vs. 13 months (CVac); p = 0.69 (HR = 1.18; CI 0.52–2.71). However CR2 patients showed a longer median PFS in the CVac-treated group (median PFS not yet reached, >13 vs. 5 months; p = 0.04, HR = 0.32 CI). OS for CR2 patients at 42 months of follow-up showed a difference of 26 months for SOC vs. > 42 months for CVac-treated (as median OS had not been reached; HR = 0.17 (CI 0.02–1.4) with a p = 0.07).

Conclusions

CVac, a mucin 1-dendritic cell maintenance treatment was safe and well tolerated in ovarian cancer patients. A variable but observed CVac-derived, mucin 1-specific T cell response was measured. Notably, CR2 patients showed an improved PFS and lengthened OS. Further studies in CR2 ovarian cancer patients are warranted (NCT01068509).

Trial registration

NCT01068509. Study Initiation Date (first patient screened): 20 July 2010. Study Completion Date (last patient observation): 20 August 2013, the last patient observation for progression-free survival; 29 April 2015, the last patient was documented regarding overall survival.

Intra-accumbal Orexin-1 Receptors are Involved in Antinociception Induced by Stimulation of the Lateral Hypothalamus in the Formalin Test as an Animal Model of Persistent Inflammatory Pain

Orexin, mainly produced by orexin-expressing neurons in the lateral hypothalamus (LH), plays an important role in pain modulation. Moreover, it is shown that the nucleus accumbens (NAc) is one of the important areas involved in this modulation. Orexin-1 (OX1) and orexin-2 (OX2) receptors are densely distributed in the NAc. The study investigated the involvement of OX1 receptors in the NAc on antinociception induced by intra-LH administration of carbachol in formalin test. Rats were unilaterally implanted by two separate cannulae into the LH and NAc. Different doses of SB334867, as an OX1 receptor antagonist, were microinjected into the NAc (1, 3 and 10 nM/0.5 µL DMSO) prior to intra-LH carbachol injection (250 nM/0.5 µL saline). Formalin test was applied as an animal model of persistent inflammatory pain. The animals received a subcutaneous injection of formalin into the hind paw, 5 min after SB334867 administration. Pain scores were calculated at 5-min blocks for a 60-min test period. Results showed that the administration of SB334867 into the NAc decreased LH chemical stimulation-induced antinociception dose-dependently in early and second phase of formalin test. Our findings showed that OX1 receptors in the NAc may be involved in modulation of inflammatory pain.

Prevalence of beta lactamase producing species of pseudomonas and acinetobacter in pediatric burn patients

Burn wound infection is a major cause of morbidity and mortality in burn victims. Pseudomonas and Acinetobacter species are among the most common organisms complicating burn wounds. Presence of extended spectrum ß-lactamase (ESBL) and metallo-ß-lactamase (MBL) genes plays an important role in spreading ß-lactam resistant strains of these organisms and is a serious condition in the treatment of the affected patients. As a result, we aimed to determine the prevalence of SHV, TEM, PER and VIM ß-lactamases in Pseudomonas and Acinetobacter species isolates from burn wound swabs of children with burn injury. In this descriptive observational study, 107 Pseudomonas and Acinetobacter isolates collected from burn patients were subjected to PCR assay. Using PCR method and DNA sequencing, the existence of SHV-, TEM-, PER- and VIM-type ß-lactamase encoding genes were determined. Out of the 107 Pseudomonas and Acinetobacter isolates, 66 (77.6%) were ESBL positive, 26.2% were positive for SHV gene, 37.4% were positive for TEM gene, 14% were positive for PER gene and 15.9% of them harbored VIM gene. More than half of the Pseudomonas and Acinetobacter strains in our pediatric burn unit harbor ß-lactamase encoding genes that make them resistant to a wide range of ß-lactam antibiotics. Consequently, it is suggested to choose an appropriate antibiotic regimen based on the antibiogram pattern of the strains.

Orientational ordering of confined hard rods: the effect of shape anisotropy on surface ordering and capillary nematization

We examine the ordering properties of rectangular hard rods with length L and diameter D at a single planar wall and between two parallel hard walls using the second virial density-functional theory. The theory is implemented in the three-state Zwanzig approximation, where only three mutually perpendicular directions are allowed for the orientations of hard rods. The effect of varying shape anisotropy is examined at L/D=10,15,and20. In contact with a single hard wall, the density profiles show planar ordering, damped oscillatory behavior, and a wall-induced surface ordering transition below the coexisting isotropic density of a bulk isotropic-nematic (I-N) phase transition. Upon approaching the coexisting isotropic density, the thickness of the nematic film diverges logarithmically, i.e., the nematic wetting is complete for any shape anisotropy. In the case of confinement between two parallel hard walls, it is found that the continuous surface ordering transition depends strongly on the distance between confining walls H for H<L, while it depends weakly on H for H>L. The minimal density at which a surface ordering transition can be realized is located at around H∼2D for all studied shape anisotropies due to the strong interference effect between the two hard walls. The first-order I-N phase transition of the bulk system becomes a surface ordered isotropic I_{B} to capillary nematic N_{B} phase transition in the slit pore. This first-order I_{B}-N_{B} transition weakens with decreasing pore width and terminates in a critical point for all studied shape anisotropies.

Klebsiella pneumonia, a Microorganism that Approves the Non-linear Responses to Antibiotics and Window Theory after Exposure to Wi-Fi 2.4 GHz Electromagnetic Radiofrequency Radiation

BACKGROUND

Drug resistance is widely believed to be an increasingly serious threat to global public health. We have previously reported that short term exposure of microorganisms to diagnostic ultrasound waves could significantly alter their sensitivity to antibiotics. In our previous studies, Klebsiella pneumoniae showed major differences in the sensitivity to antibiotics in exposed and non-exposed samples. This study was aimed at investigating the alteration of antibiotic resistance of Klebsiella pneumonia, after exposure to Wi-Fi 2.4 GHz electromagnetic radiofrequency radiation.

MATERIALS AND METHODS

In this in vitro study, three replicate agar plates were used for each test. The antibiotic susceptibility test was carried out using disc diffusion method on Mueller Hinton agar plates and the inhibition zones in both control and exposed groups were measured. A common Wi-Fi router was used in this study as the radiofrequency exposure source. Irradiated samples were exposed to Wi-Fi radiofrequency radiation for 3, 4.5 and 8 hours.

RESULTS

Statistically significant variations of sensitivity to antibiotics were found for all studied antibiotics after 4.5 hours of RF exposure, compared to non-exposed bacteria. Interestingly, the mean diameters of the inhibition zones after 3 hours of exposure were less than those exposed for 4.5 hours. Following this rise in the sensitivity to antibiotics, a fall was observed in the bacteria exposed for 8 hours for all studied antibiotics.

CONCLUSION

The findings of this study show a statistically significant rise in the sensitivity of Klebsiella pneumoniae to different antibiotics after 4.5 hours of exposure to 2.4 GHz Wi-Fi radiation, followed by a fall after 8 hours of exposure. These observations can be interpreted by the concept of non-linearity in the responses of Klebsiella pneumoniae to different antibiotics after exposure to electromagnetic radiofrequency radiation. As in this study a minimum level of effect was needed for the induction of adaptive response, these results also confirm the validity of the so-called "window theory".

Bacterial contamination of different components of the waterpipe

SETTING

Waterpipe smoking is an emerging topic in tobacco research that may have unrecognised health hazards.

OBJECTIVE

To determine whether waterpipes are a source of bacterial contamination.

METHODS

A total of 15 restaurants and waterpipe cafés were randomly selected from the list of locations serving waterpipe tobacco in Kerman city, Iran. Different parts of the waterpipe devices were sampled, including the disposable mouthpiece, the mouthpiece of the hose and the water in the bowl of the waterpipe. The samples were smeared onto bacterial culture media, including eosin methylene blue, blood agar and MacConkey agar growth media, and incubated at 37°C. After 24-48 h, they were examined for colony growth.

RESULTS

Of 285 samples from different parts of the waterpipes, 236 (82.8%) showed positive cultures; the rate of contamination ranged from 69% in the fixed mouthpiece to 96% in bowl water. Coagulase-negative staphylococci (32.9%), Streptococcus spp (26.9%), Neisseria spp (13.7%) and Escherichia coli (9.4%) were the most frequent contaminants.

CONCLUSION

Waterpipes are frequently contaminated with microorganisms. This study revealed potential microbial hazards in waterpipes that may contribute to respiratory tract colonisation.