Isolation and Characterization of Lytic Bacteriophage Against Multi-drug Resistant Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen frequently causing healthcare-associated infections. The apocalyptic rise of antimicrobial resistance has rekindled interest in age-old phage therapy that uses phages (viruses that infect bacteria) to kill the targeted pathogenic bacteria. Because of its specificity, phages are often considered as potential personalized therapeutic candidate for treating bacterial infections.

METHODS

In this study, we isolated and purified lytic phages against multi-drug resistant P. aeruginosa using soft agar overlay technique. Phage characteristics like thermal and pH stability, latent period and burst size were determined using one-step growth assay while multiple host range spectrum was determined by spot assay. The phages were further characterized using protein profiling.

RESULTS

Three Pseudomonas phages (øCDBT-PA31, øCDBT-PA56 and øCDBT-PA58) were isolated from the holy rivers of Kathmandu valley. Among 3 phages, øCDBT-PA31 demonstrated multiple host range and could lyse multi-drug resistant strain of P. aeruginosa. Further, øCDBT-PA31 showed latent period of 30 minutes with corresponding burst sizes of 423-525 PFU/cell. Interestingly, øCDBT-PA31 also tolerated a wide range of adverse conditions, such as high temperature (50°C) and pH 3-11. Further, protein profiling revealed that øCDBT-PA31 has 4 and øCDBT-PA11 had 3 distinct bands in the gradient gel ranging from approximately 3.5-29 kilodaltons (kDa) suggesting them to be morphologically distinct from each other.

CONCLUSIONS

As multi-drug resistant bacteria are emerging as a global problem, lytic phages can be an alternative treatment strategy when all available antibiotics fail.

Azithromycin and cefixime combination versus azithromycin alone for the out-patient treatment of clinically suspected or confirmed uncomplicated typhoid fever in South Asia: a randomised controlled trial protocol

Background: Typhoid and paratyphoid fever (enteric fever) is a common cause of non-specific febrile infection in adults and children presenting to health care facilities in low resource settings such as the South Asia.  A 7-day course of a single oral antimicrobial such as ciprofloxacin, cefixime, or azithromycin is commonly used for its treatment. Increasing antimicrobial resistance threatens the effectiveness of these treatment choices. We hypothesize that combined treatment with azithromycin (active mainly intracellularly) and cefixime (active mainly extracellularly) will be a better option for the treatment of clinically suspected and culture-confirmed typhoid fever in South Asia.

Methods: This is a phase IV, international multi-center, multi-country, comparative participant-and observer-blind, 1:1 randomised clinical trial. Patients with suspected uncomplicated typhoid fever will be randomized to one of the two interventions: Arm A: azithromycin 20mg/kg/day oral dose once daily (maximum 1gm/day) and cefixime 20mg/kg/day oral dose in two divided doses (maximum 400mg bd) for 7 days, Arm B: azithromycin 20mg/kg/day oral dose once daily (max 1gm/day) for 7 days AND cefixime-matched placebo for 7 days. We will recruit 1500 patients across sites in Bangladesh, India, Nepal, and Pakistan. We will assess whether treatment outcomes are better with the combination after one week of treatment and at one- and three-months follow-up.

Discussion: Combined treatment may limit the emergence of resistance if one of the components is active against resistant sub-populations not covered by the other antimicrobial activity. If the combined treatment is better than the single antimicrobial treatment, this will be an important result for patients across South Asia and other typhoid endemic areas.

Clinicaltrials.gov registration: NCT04349826 (16/04/2020)

Azithromycin and cefixime combination versus azithromycin alone for the out-patient treatment of clinically suspected or confirmed uncomplicated typhoid fever in South Asia: a randomised controlled trial protocol

Background: Typhoid and paratyphoid fever (enteric fever) is a common cause of non-specific febrile infection in adults and children presenting to health care facilities in low resource settings such as the South Asia.  A 7-day course of a single oral antimicrobial such as ciprofloxacin, cefixime, or azithromycin is commonly used for its treatment. Increasing antimicrobial resistance threatens the effectiveness of these treatment choices. We hypothesize that combined treatment with azithromycin (active mainly intracellularly) and cefixime (active mainly extracellularly) will be a better option for the treatment of clinically suspected and culture-confirmed typhoid fever in South Asia. Methods: This is a phase IV, international multi-center, multi-country, comparative participant-and observer-blind, 1:1 randomised clinical trial. Patients with suspected uncomplicated typhoid fever will be randomized to one of the two interventions: Arm A: azithromycin 20mg/kg/day oral dose once daily (maximum 1gm/day) and cefixime 20mg/kg/day oral dose in two divided doses (maximum 400mg bd) for 7 days, Arm B: azithromycin 20mg/kg/day oral dose once daily (max 1gm/day) for 7 days AND cefixime-matched placebo for 7 days. We will recruit 1500 patients across sites in Bangladesh, India, Nepal, and Pakistan. We will assess whether treatment outcomes are better with the combination after one week of treatment and at one- and three-months follow-up. Discussion: Combined treatment may limit the emergence of resistance if one of the components is active against resistant sub-populations not covered by the other antimicrobial activity. If the combined treatment is better than the single antimicrobial treatment, this will be an important result for patients across South Asia and other typhoid endemic areas. Clinicaltrials.gov registration: NCT04349826 (16/04/2020).

Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial

BACKGROUND

Typhoid fever is a major public health problem in low-resource settings. Vaccination can help curb the disease and might reduce transmission. We have previously reported an interim analysis of the efficacy of typhoid conjugate vaccine (TCV) in Nepali children. Here we report the final results after 2 years of follow-up.

METHODS

We did a participant-masked and observer-masked individually randomised trial in Lalitpur, Nepal, in which 20 019 children aged 9 months to younger than 16 years were randomly assigned in a 1:1 ratio to receive a single dose of TCV (Typbar TCV, Bharat Biotech International, India) or capsular group A meningococcal conjugate vaccine (MenA). Participants were followed up until April 9, 2020. The primary outcome was blood culture-confirmed typhoid fever. Cases were captured via passive surveillance and active telephone surveillance followed by medical record review. The trial is registered at ISRCTN registry, ISRCTN43385161 and is ongoing.

FINDINGS

From Nov 20, 2017, to April 9, 2018, of 20 119 children screened, 20 019 participants were randomly assigned to receive TCV or MenA vaccine. There were 75 cases of blood culture-confirmed typhoid fever included in the analysis (13 in the TCV group and 62 in the MenA group) over the 2-year period. The protective efficacy of TCV against blood culture-confirmed typhoid fever at 2 years was 79·0% (95% CI 61·9-88·5; p<0·0001). The incidence of typhoid fever was 72 (95% CI 38-123) cases per 100 000 person-years in the TCV group and 342 (95% CI 262-438) cases per 100 000 person-years in the MenA group. Adverse events occurring within the first 7 days post-vaccination were reported previously.

INTERPRETATION

The final results of this randomised, controlled trial are in keeping with the results of our published interim analysis. There is no evidence of waning protection over a 2-year period. These findings add further support for the WHO recommendations on control of enteric fever.

FUNDING

Bill & Melinda Gates Foundation.

Nepali Translation and Reliability Analysis of Quantitative Androgen Deficiency in the Aging Male Questionnaire

Background Androgen deficiency is diagnosed on the basis of clinical symptoms and laboratory assessment of testosterone level. Different screening tools have been developed to evaluate the sign and symptoms. Objective In this study, we examine the validity and reliability of the Nepali version of the quantitative Androgen Deficiency in Aging Male (qADAM) questionnaire to screen androgen deficiency in Nepali male. Method English dialectal quantitative Androgen Deficiency in Aging Male questionnaire was forward translated to Nepali version and backward translated. This version was reviewed by a panel of an endocrinologist, a clinical psychiatrist, a physician, and a clinical biochemist. A final Nepali version of qADAM was developed. Thirty-one healthy male aged 31-70 years were administered with the questionnaire in two separate occasions two weeks apart. Cronbach's alpha and test-retest reliability were calculated to identify validity and reliability, respectively. Result In the Nepali translated questionnaire, Cronbach's alpha for internal consistency from ten items is good (0.68). The Cronbach's alpha for internal consistency from nine items without item 7 is 0.706. Seven out of ten items had an R-value of > 0.7. In the total sample, Standard Error Mean (SEM) ranged from 0.00-0.44 for qADAM. SEM% are low for all variables (0.00-11.20%). MDC95 ranged 0.00-1.234. MDC95% ranged 0.00 - 31.05% and was < 30% for majority of variables (90%). Conclusion The final translated Nepali questionnaire seems reliable and valid. A future study measuring the Nepali questionnaire with testosterone level and another biochemical test in control and androgen deficiency patients will help validate the questionnaire.

Swyer syndrome in a woman with pure 46,XY gonadal dysgenesis: a rare presentation

46,XY pure gonadal dysgenesis (Swyer syndrome) is a rare cause of disorder of sexual development. It is a genetic aberration characterized by a 46,XY karyotype which are phenotypical females, with female genitalia at birth, and normal Müllerian structures. The condition usually becomes apparent first in adolescence with delayed puberty and primary amenorrhea. Herein the authors present the case of a 27-year-old woman with primary amenorrhea and undeveloped breasts. The patient had pure 46,XY gonadal dysgenesis with hypoplastic uterus, estrogen treatment for amenorrhea, and no neoplastic changes on the histopathology report. The authors highlight the high risk of neoplastic transformation of the patient with gonadal dysgenesis, and 46,XY karyotype should be referred for bilateral gonadectomy. Once the diagnosis of Swyer syndrome is established, early treatment is crucial to prevent the development of gonadal malignancy and to enable a normal sex life, and even carry a fetus in an immature uterus.

Still-birth--a tragic journey: a critical analysis

Despite improvement in antenatal and intrapartum care, late intrauterine fetal death at and after 28 weeks of gestation remains a persistent and challenging problem to the obstetricians. We undertook the retrospective review of the medical records of 89 women with singleton pregnancy who gave birth to still-born infants at or more than 28 weeks gestation during the period from April 1998 to April 2007 at Nepal Medical College Teaching Hospital to know the prevalence rate and devise preventive measures for still-born infants which accounts more than 50.0% of perinatal death in Nepal. Major malformations were present in 5 (5.6%) of 89 infants including three infants with neural tube abnormalities. Pre-eclampsia preceded the stillbirth and might have been an indirect cause of stillbirth in 16 (19.0%) of 84 women whose infants had normal formations. The cause of still birth in 68 non-pre-eclamptic women was unclear in 31 (45.6%) home breech delivery with head stuck in 11 (16.0%), abruptio placentae in 5 (7.3%), intrauterine fetal growth restriction in 10 (14.7%), infection in 6 (8.8%) and cord accidents in 5 (7.3%). The causes of still births were many and varied, with large population having no obvious cause, although autopsy was not done in any case in this study. Proper monitoring of women with preeclampsia and early diagnosis and prompt delivery for women with abruption placenta might be helpful in reducing the number of stillbirths. Great advocacy with community education on importance of community focused antenatal care and increasing institutional delivery with availability of emergency obstetric care is necessary to decrease the number of stillbirths and perinatal mortality in developing countries like Nepal.