The role of identified and characterized bacteriophage ZCEC13 in controlling pathogenic and multidrug-resistant Escherichia coli in wastewater: in vitro study

AbstractThe spread and development of Multi-Drug Resistant (MDR) bacteria in wastewater became beyond control and a global public health concern. The conventional disinfectants used in wastewater treatment methods have been becoming increasingly ineffective against a range of pathogenic and MDR bacteria. Bacteriophages are considered a novel approach to microbial control. Therefore, this study aims to explore the possibility of using phages against pathogenic and MDR Escherichia coli strains isolated from wastewater treatment plants. The wastewater samples were collected from two different treatment plants for E. coli isolation. The antibiotic sensitivity profile and occurrence of virulence and resistant genes were tested in twenty-eight (28) E. coli isolates. Phage ZCEC13 was selected based on its promising activity and host range to undergo identification and characterization. ZCEC13 was evaluated by transmission electron microscopy, genomic sequencing, in vitro lytic activity and tested for its stability under different conditions such as pH, Ultraviolet light exposure, and temperature. The results reported that ZCEC13 belongs to the Caudoviricetes class, with a high antibacterial dynamic. Phage ZCEC13 displayed high stability at different pH values ranging from 2 to 12, good tolerance to temperatures from -4 to 65 ^oC, and high stability at UV exposure for 120 mins. Respectively, the findings showed stability of the phage under several conditions and high efficiency in killing MDR bacteria isolated from the treatment plants. Further studies are encouraged to analyze the efficacy of phages as a microbial control agent in wastewater treatment plants.

Phage-Encoded Endolysins

Due to the global emergence of antibiotic resistance, there has been an increase in research surrounding endolysins as an alternative therapeutic. Endolysins are phage-encoded enzymes, utilized by mature phage virions to hydrolyze the cell wall from within. There is significant evidence that proves the ability of endolysins to degrade the peptidoglycan externally without the assistance of phage. Thus, their incorporation in therapeutic strategies has opened new options for therapeutic application against bacterial infections in the human and veterinary sectors, as well as within the agricultural and biotechnology sectors. While endolysins show promising results within the laboratory, it is important to document their resistance, safety, and immunogenicity for in-vivo application. This review aims to provide new insights into the synergy between endolysins and antibiotics, as well as the formulation of endolysins. Thus, it provides crucial information for clinical trials involving endolysins.

Implication of CDKAL1 single-nucleotide polymorphism rs 9465871 in obese and non-obese Egyptian children

INTRODUCTION

CDKAL1 single-nucleotide polymorphism rs 9465871variant is a risk locus for Type 2 Diabetes (T2DM).The study evaluated the associations of CDKAL1- rs9465871 with glycosylated hemoglobin A1C Level (HbA1c), fasting insulin level, insulin resistance and metabolic syndrome among obese and non- obese Egyptian children.

MATERIALS AND METHODS

The study included 43 obese children and 40 normal weight children. Anthropometric body measurements, bio-specimen and biochemistry assays were done. Genotyping of rs9465871 (CDKAL1) was conducted.

RESULTS

The percentages of the CC, CT, and TT genotypes of rs9465871in the lean children were 15%, 42.5%, and 42.5%, respectively. Regarding obese children, the frequencies were 18.6%, 58.1% and 23.3% respectively with no significant statistical difference. Comparison between the CDKAL1 rs 9465871 polymorphism showed that the highest value of fasting insulin was recorded in CC genotype (22.80± 15.18 [uIU/mL] P<.014). Levels of HOMA-IR, FBS and HBA1C were highest in CC group with no statistical significant differences. However, fasting insulin level was higher in the CC group than in the TT+ CT group (P<.01). A higher level of HbA1c was found among CC group at CDKAL1-rs9465871 (5.9%) than TT+CT genotype group (5.6%), with no statistical significant difference. There was increase in the risk of type 2 diabetes the percentages were 78.6% and 46.4% respectively when comparing CC with TT+CT genotype groups ( P<.039). CC group was not associated with significant increase in metabolic syndrome.

CONCLUSION

There is a significant risk association between CDKAL1-rs9465871polymorphism and development of T2DM in a subset of the Egyptian children.

Treatment of chronic rhinosinusitis and its effects on asthma

The effects of rhinosinusitis treatment upon asthma are disputed. The first randomised prospective study of surgical compared with medical therapy of chronic rhinosinusitis in 90 patients with and without nasal polyps was previously reported. Asthma symptoms, control, forced expiratory volume in one second (FEV1), peak flow, exhaled nitric oxide, medication use and hospitalisation at 6 and 12 months from the start of the study were also monitored. This paper reports these results in 43 of those patients with concomitant asthma. Both medical and surgical treatment of chronic rhinosinusitis were associated with subjective and objective improvements in asthma. Overall asthma control improved significantly following both treatment modalities, but was better maintained after medical therapy, where improvement could also be demonstrated in the subgroup with nasal polyps. Medicine was superior to surgery with respect to a decrease in exhaled nitric oxide and increase in FEV1 in the polyp patients. Two patients noted worsening of asthma post-operatively. Improvement in upper airway symptoms, as assessed using a visual analogue scale, correlated with improvement in asthma symptoms and control. Treatment of chronic rhinosinusitis, medical or surgical, benefits concomitant asthma; that associated with nasal polyposis benefits more from medical therapy.

Comparison of caffeine-induced changes in cerebral blood flow and middle cerebral artery blood velocity shows that caffeine reduces middle cerebral artery diameter

Changes in cerebral blood flow (CBF) can be assessed directly with xenon clearance (XeC) or indirectly by measuring changes in middle cerebral artery blood velocity (Vmca) with transcranial Doppler (TCD). The aim of this study was to compare the changes in CBF and Vmca following caffeine ingestion. Nineteen patients (age 48-86, recovering from an acute stroke) and ten controls (age 52-85) were each studied twice. Bilateral measurements of CBF and Vmca were made before and after ingestion of 250 mg caffeine or matched placebo. The percentage change in CBF and Vmca after caffeine was calculated. Full results (CBF and Vmca) were obtained from 14 patients and 9 controls. There was no significant difference between patients and controls, so results were combined. Caffeine reduced CBF by 22% (95% confidence interval (CI) = 17% to 28%) and reduced Vmca by 13% (95% CI = 10% to 17%). The fall in Vmca was significantly less than that in CBF (p = 0.0016), showing that caffeine reduces mca diameter. Analysis based on Poiseuille flow in the arterioles suggests that caffeine reduced arteriole diameter by 5.9% (95% CI = 4.6% to 7.3%) and mca diameter by 4.3% (95% CI = 2.0% to 6.6%). TCD is being used as an alternative to XeC for assessing the effect of vasoconstrictors and vasodilators on CBF. This study has demonstrated that in mca diameter can be changed by the vasoactive agents, and that changes in Vmca do not necessarily reflect changes in CBF.

Ability to learn inhaler technique in relation to cognitive scores and tests of praxis in old age

Clinical observations have shown that some older patients are unable to learn to use a metered dose inhaler (MDI) despite having a normal abbreviated mental test (AMT) score, possibly because of dyspraxia or unrecognised cognitive impairment. Thirty inhaler-naive inpatients (age 76-94) with an AMT score of 8-10 (normal) were studied. Standard MDI training was given and the level of competence reached was scored (inhalation score). A separate observer performed the minimental test (MMT), Barthel index, geriatric depression score (GDS), ideational dyspraxia test (IDT), and ideomotor dyspraxia test (IMD). No correlative or threshold relationship was found between inhalation score and Barthel index, GDS, or IDT. However, a significant correlation was found between inhalation score and IMD (r = 0.45, p = 0.039) and MMT (r = 0.48, p = 0.032) and threshold effects emerged in that no subject with a MMT score of less than 23/30 had an inhalation score of 5/10 or more (adequate technique requires 6/10 or more), and all 17/18 with an inhalation score of 6/10 or more had an IMD of 14/20 or more. The three patients with a MMT >22 and inhalation score <6 had abnormal IMD scores. Inability to learn an adequate inhaler technique in subjects with a normal AMT score appears to be due to unrecognised cognitive impairment or dyspraxia. The MMT is probably a more useful screening test than the AMT score in this context.

An open audit of montelukast, a leukotriene receptor antagonist, in nasal polyposis associated with asthma

BACKGROUND

Nasal polyposis occurs frequently in patients with intrinsic asthma, especially in those who are aspirin sensitive. It can be difficult to treat effectively, even with surgery and regular topical intranasal corticosteroids many patients are still symptomatic.

OBJECTIVE

To investigate the response to montelukast, a leukotriene D4 receptor antagonist, as an add-on therapy to topical and inhaled corticosteroids in patients, both aspirin sensitive (AS) and aspirin tolerant (AT), with nasal polyposis and asthma.

METHODS

Nasal polyposis symptoms were assessed by visual analogue scales; nasal polyps were assessed by nasendoscopy and via the measurement of nasal volumes by acoustic rhinometry. The nasal airway was assessed by nasal inspiratory peakflow (NIPF). Asthma was monitored using symptom scores and peak expiratory flow measurements. Aspirin sensitivity was assessed by history together with intranasal lysine aspirin challenge. Upper and lower airway nitric oxide measurements were made before and during treatment.

RESULTS

Clinical subjective improvement in nasal polyposis occurred in 64% AT (P < 0.01), patients and 50% AS patients (P > 0.05); asthma improvement in 87% AT and 61% AS patients (P < 0.05 for both). Objective changes in peak flow occurred only in AT patients (P < 0.05). Acoustic rhinometry, nasal inspiratory peak flow and nitric oxide levels did not change significantly in any group, however, correlations were seen between nitric oxide levels and polyp scores and between nitric oxide levels and acoustic rhinometry changes. Improvement on montelukast therapy was not associated with any of the following variables: age, sex, skin prick test positivity, disease duration or aspirin sensitivity. (P > 0.05 for all).

CONCLUSION

The findings are consistent with a subgroup of nasal polyps/asthma patients in whom leukotriene receptor antagonists are effective. This is not related to aspirin sensitivity. Further placebo-controlled studies need to be undertaken.

Role of IgE in primary murine Schistosomiasis mansoni

Schistosoma mansoni infection proceeds in normal mice in the absence of detectable levels of polyclonal or specific immunoglobulin (Ig)E until worms mature and deposit eggs. Hence, the course of a primary S. mansoni infection is not expected to vary appreciably in mice with defects in the IgE production. Experimental increase of IgE production early after infection may, however, influence worm development. In the first approach towards this goal, BALB/c mice were injected with interleukin(IL)4 to raise the level of endogenously synthesized IgE. A significant increase in serum polyclonal IgE and antischistosome IgG1 during the prepatent period was not associated with significant changes in worm and egg burden or liver pathology. During the second approach, mice were injected with IgE which was affinity purified from serum of BALB/c mice infected for 16 weeks with S. mansoni. The purified IgE bound to carbohydrate-independent epitopes of soluble antigens from 3 h larvae, adult worms and eggs and recognized the schistosomular surface membrane. No differences in worm and egg load or granuloma number and size were noted between untreated and exogenous IgE-injected mice. Together, the data demonstrate that by itself IgE does not influence the outcome of infection in primary murine S. mansoni.

Complications of intra-aortic balloon counterpulsation. The role of catheter size and duration of support in a multivariate analysis of risk

AIMS

The aim of this study was to assess the risk of intra-aortic balloon counterpulsation and to identify clinical and procedural variables that would predict complications.

METHODS AND RESULTS

We analysed 381 consecutive patients who were treated between 1977 and 1995 at our catheterization laboratory and/or medical intensive care unit. The complications considered relevant were limb ischaemia requiring catheter removal, vascular injury, bleeding requiring transfusion, embolic events, and infection. In eight patients the balloon could not be inserted. The rate of complications for the remaining 373 patients was 12.9%. Between 1977 and 1980, surgical insertion was performed using a 12 French catheter with a complication rate of 30.4% (seven of 23 patients). Percutaneous implantation, performed after 1981, had an overall complication rate of 11.7% (41 of 350 patients). Using thinner catheters for percutaneous placement was associated with a reduction in the rate of complications, from 20.7% (17 of 82 patients) for 12 French catheters to 9.9% (10 of 101 patients) for 10.5 French catheters (P = 0.04), and 8.4% (14 of 167 patients) for 9.5 French catheters (P = 0.006). Multivariate logistic regression analysis identified duration of counterpulsation > 48 h (odds ratio 3.6), catheter size (odds ratio 3.4 for 12 French catheters), peripheral vascular disease (odds ratio 2.7), and shock (odds ratio 2.0) as independent risk factors for counterpulsation-associated complications. When considering 9.5 French catheters only (167 patients, all after 1992), the sole remaining independent risk factor was duration of counterpulsation > 48 h (odds ratio 3.8). Those patients with 9.5 French catheters in whom counterpulsation did not exceed 48 h had a low complication rate of 3.9%.

CONCLUSION

The rate of percutaneous intra-aortic balloon counterpulsation complications was thus significantly reduced by employing thinner catheters. It was at an acceptable level for 9.5 French catheters, where a long duration of counterpulsation emerged as the most significant factor associated with complications. Whether using even thinner catheters in combination with a sheathless implantation technique further minimizes the risk of counterpulsation remains to be seen.