Streptococcus-lignende infeksjoner i oppdrettet tilapia (Oreochromis niloticus) fra Karibasjøen : karakterisering av patogene arter og vertsresponser

Zambia is one of the largest aquaculture producers in sub-Saharan Africa, with tilapia production having increased exponentially during the last 20 years. Lake Kariba is the most active commercial fish farming site in the country at the moment, with several farms operating intensive cage farming of Nile tilapia (Oreochromis niloticus). Along with intensification of tilapia production over the last years, came diseases that have been reported since 2014 albeit without being well characterized. Increased mortalities and clinical signs suggestive of streptococcus like infections were reported in outbreaks. The overall objective of this study was to characterize streptococcus-like bacteria causing disease in farmed Nile tilapia on Lake Kariba with a view of developing a vaccine to protect the fish.Zambia er en av de største akvakulturnasjonene i Afrika sør for Sahara, og tilapia-produksjonen har økt kraftig de siste 20 årene. Lake Kariba er hovedsete for kommersielt oppdrett for øyeblikket, med flere anlegg som driver intensivt merdoppdrett av nil-tilapia (Oreochromis niloticus). Sammen med intensivering av tilapiproduksjon over de siste årene, kom sykdommer. De første tilfellene rapportert i 2014, men årsaken til dødeligheten ble ikke bestemt. Senere ble det påvist økt dødelighet og med kliniske tegn på streptokokk-infeksjon i forbindelse med sykdomsutbrudd. På denne bakgrunnen, var det overordnede målet for denne studien å karakterisere streptokokk-lignende bakterier som årsak til sykdom i oppdrettet nil-tilapia i Karibasjøen med sikte på å utvikle en vaksine mot sykdommene.NORA

Towards a competency-based doctoral curriculum at the University of Zambia: lessons from practice

We describe a collaborative, iterative, and participatory process that we undertook to develop and adopt a competency-based doctoral curriculum framework at the University of Zambia. There needs to be more than the traditional unstructured apprenticeship of PhD training in a knowledge-based economy where PhD graduates are expected to contribute to industry problem-solving. The lack of industry-driven competencies and, to some extent, limited skills possessed by PhD graduates relative to the demands of employers has led to the misclassification of doctoral degrees as mere paper certificates. Further, under traditional PhD training without specific core competencies, it has led to criticisms of such PhD studies as a waste of resources. The calls to rethink doctoral development in broader employment contexts led many countries to redesign their PhD programs. Training has increasingly introduced industrial linkages and industry-defined research projects to increase the attractiveness of doctoral students. Whereas developed countries have made significant reforms towards competency-based PhD training, little or nothing has been done in developing countries, especially in sub-Saharan Africa. This against the demands that Africa needs more than 100,000 PhDs in the next decade to spur economic development. Against this background, the University of Zambia has developed an industry-driven structured competency-based PhD curriculum framework. The framework will guide and support the development of standardized program-specific PhD curricula, delivery, and assessment of competencies at the University of Zambia, ensuring that doctoral students acquire skills and demonstrate core competencies that are transferable and applicable in industry settings. This framework focuses on the development of specific competencies that are necessary for successful PhD completion. The competencies are divided into three main categories: research, teaching, and professional development. Each category is then broken down into ten core competencies from which respective doctoral programs will develop sub-competencies. It is from these core competencies and sub-competencies that learning outcomes, assessment methods, and teaching activities are developed. It is envisioned that this new competency-based doctoral curriculum framework will be a helpful tool in training a cadre of professionals and researchers who benefit the industry and contribute to economic and societal development

Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

Background High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. Methods We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UK based ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. Findings Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45–116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants’ systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2–5; n=420) in the GTN group versus 3 (2–5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97–1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2–5]; n=544, in the GTN group vs 3 [2–5]; n=558, in the sham group; 1·04 [0·84–1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. Interpretation Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultraacute prehospital setting. Funding British Heart Foundation

Lactococcus garvieae isolated from Lake Kariba (Zambia) has low invasive potential in Nile tilapia (Oreochromis niloticus)

The pathogenesis of Lactococcus garvieae (L. garvieae) was assessed in Nile tilapia (Oreochromis niloticus) following administration by two different routes of infection (intraperitoneal versus immersion), using 180 fish divided into three groups. The first group of fish was injected intraperitoneally (IP) with 3 × 105 colony-forming units (cfu) of L. garvieae; the second group was infected by immersion (IMM) into water containing 9.6 × 105 cfu/ml L. garvieae, and in group 3 (Control), the fish were injected IP with sterile normal saline. Mortalities were recorded daily, and on 3, 5, 7, and 13 days post-infection (dpi), liver, kidney, spleen, brain and eyes were sampled. The level of infection between groups was assessed by number of mortalities that occurred, pathology/histopathology of internal organs, bacterial re-isolation and presence of bacteria in situ determined using immunohistochemistry. A significant difference (p < .0001) was observed between L. garvieae re-isolation from tilapia following administration by IP injection and IMM. Similarly, more clinical signs and mortalities (p < .001) were observed in the IP group compared to the IMM group where no mortalities were observed. These findings suggest that L. garvieae has a low invasive potential in Nile tilapia with intact skin/external barriers and highlights the importance of maintaining fish without cuts or abrasions under field conditions

A whole-cell Lactococcus garvieae autovaccine protects Nile tilapia against infection

The autovaccine was produced in-house using a bacterial isolate from a diseased fish from the target farm. Three groups of 150 fish each were injected with either 1) an oil-adjuvanted, inactivated whole cell autovaccine, 2) adjuvant only or 3) PBS (negative control). Approximately 660 degree days post vaccination, the fish were challenged with 9x105 cfu bacteria/fish by intraperitoneal injection and monitored for a further 28 days. Protection against infections was measured by lack of/reduced bacterial loads both by bacterial re-isolation and immunohistochemistry as well as absence of clinical signs/pathology. Significantly less L. garvieae (p<0.03) was re-isolated from either the adjuvant only or control groups compared to the vaccinated group. Furthermore, a significantly high amount (p<0.001) of anti-L. garvieae specific antibodies were observed in the vaccinated group compared to the adjuvant only or control groups at time of challenge. This coincided with protection against infection measured by absence/reduced L. garvieae re-isolation from internal organs, reduced clinical signs and lack of pathology in this group. In the adjuvant only and control groups, bacteria were re-isolated from the kidney, liver, spleen, brain and eyes during the first 14 days. The findings suggest that oil-based vaccines can protect tilapia against L. garvieae infection through an antibody mediated response.publishedVersio

A whole-cell Lactococcus garvieae autovaccine protects Nile tilapia against infection

The autovaccine was produced in-house using a bacterial isolate from a diseased fish from the target farm. Three groups of 150 fish each were injected with either 1) an oil-adjuvanted, inactivated whole cell autovaccine, 2) adjuvant only or 3) PBS (negative control). Approximately 660 degree days post vaccination, the fish were challenged with 9x105 cfu bacteria/fish by intraperitoneal injection and monitored for a further 28 days. Protection against infections was measured by lack of/reduced bacterial loads both by bacterial re-isolation and immunohistochemistry as well as absence of clinical signs/pathology. Significantly less L. garvieae (p<0.03) was re-isolated from either the adjuvant only or control groups compared to the vaccinated group. Furthermore, a significantly high amount (p<0.001) of anti-L. garvieae specific antibodies were observed in the vaccinated group compared to the adjuvant only or control groups at time of challenge. This coincided with protection against infection measured by absence/reduced L. garvieae re-isolation from internal organs, reduced clinical signs and lack of pathology in this group. In the adjuvant only and control groups, bacteria were re-isolated from the kidney, liver, spleen, brain and eyes during the first 14 days. The findings suggest that oil-based vaccines can protect tilapia against L. garvieae infection through an antibody mediated response

Characterization of streptococcus-like bacteria from diseased Oreochromis niloticus farmed on Lake Kariba in Zambia

Tilapia (Oreochromis niloticus) farming on Lake Kariba, Zambia has been practiced since early 2000s. In recent years, the industry has experienced disease outbreaks with clinical signs consistent with streptococcus-like infections. Affected fish were growers weighing approximately 200 g or above from farms designated A and B, reared in cages on the lake. The objective of this study was to identify and characterize the causative bacteria of these outbreaks. A total of eighty-six diseased fish were sampled between 2014 and 2016. Bacteria were cultured from internal organs and were characterized by biochemical tests, PCR and sequencing of the 16S rRNA gene or 16Ssingle bond23S intergenic spacer region. The results showed the prevalence of Lactococcus garvieae at farm A in 2015 and 2016 outbreaks (15/20 and 23/40, respectively) and at farm B (6/20) in 2016. Infection of naïve fish with one isolate of L. garvieae recovered from the outbreaks resulted in clinical signs and mortalities akin of what had been observed during the outbreaks, confirming Koch's postulates. In the 2014 outbreaks, the low prevalence of Streptococcus agalactiae (4/15 and 2/11 respectively at farms A and B) and S. iniae (2/15) at farm A suggests that other pathogens were likely involved in the disease outbreak observed

Characterization of streptococcus-like bacteria from diseased Oreochromis niloticus farmed on Lake Kariba in Zambia

Tilapia (Oreochromis niloticus) farming on Lake Kariba, Zambia has been practiced since early 2000s. In recent years, the industry has experienced disease outbreaks with clinical signs consistent with streptococcus-like infections. Affected fish were growers weighing approximately 200 g or above from farms designated A and B, reared in cages on the lake. The objective of this study was to identify and characterize the causative bacteria of these outbreaks. A total of eighty-six diseased fish were sampled between 2014 and 2016. Bacteria were cultured from internal organs and were characterized by biochemical tests, PCR and sequencing of the 16S rRNA gene or 16Ssingle bond23S intergenic spacer region. The results showed the prevalence of Lactococcus garvieae at farm A in 2015 and 2016 outbreaks (15/20 and 23/40, respectively) and at farm B (6/20) in 2016. Infection of naïve fish with one isolate of L. garvieae recovered from the outbreaks resulted in clinical signs and mortalities akin of what had been observed during the outbreaks, confirming Koch's postulates. In the 2014 outbreaks, the low prevalence of Streptococcus agalactiae (4/15 and 2/11 respectively at farms A and B) and S. iniae (2/15) at farm A suggests that other pathogens were likely involved in the disease outbreak observed.publishedVersio

Acceptability of a trial of vaginal progesterone for the prevention of preterm birth among HIV-infected women in Lusaka, Zambia: A mixed methods study.

Antenatal progesterone prevents preterm birth (PTB) in women with a short cervix or prior PTB in daily vaginal or weekly injectable formulations, respectively. Neither has been tested for the indication of maternal HIV, which is associated with an elevated risk of PTB. The Vaginal Progesterone (VP) Trial was a pilot feasibility study of VP to prevent HIV-related PTB in Lusaka, Zambia. Using mixed methods, we concurrently evaluated the acceptability of the trial and the study product among participants. Over a 1-year period, we enrolled 140 pregnant women living with HIV into a double-masked, placebo-controlled, randomized trial of daily self-administered VP or placebo. We administered an endline questionnaire to all participants and conducted in-depth interviews with 30 participants to assess barriers and facilitators to uptake and retention in the trial and to study product adherence. All interviews were audiotaped, transcribed, translated into English as needed, and independently coded by two analysts to capture emerging themes. Of 131 participants who completed the questionnaire, 128 (98%) reported that nothing was difficult when asked the hardest part about using the study product. When given a hypothetical choice between vaginal and injectable progesterone, 97 (74%) chose vaginal, 31 (24%) injectable, and 3 (2%) stated no preference. Most interviewees reported no difficulties with using the study product; others cited minor side effects and surmountable challenges. Strategies that supported adherence included setting alarms, aligning dosing with antiretrovirals, receiving encouragement from friends and family, sensing a benefit to their unborn baby, and positive feedback from study staff. Participants who reported preference of a vaginal medication over injectable described familiarity with the vaginal product, a fear of needles and resulting pain, and inconvenience of a weekly clinic visit. Those who would prefer weekly injections cited fewer doses to remember. Perceived barriers to study participation included mistrust about the motivations behind research, suspicion of Satanism, and futility or possible harm from a placebo. We report key influences on acceptability of a randomized trial of VP to prevent PTB among HIV-infected women in Zambia, which should inform methods to promote uptake, adherence, and retention in a full-scale trial

IPBES Invasive Alien Species Assessment: Chapter 6. Governance and policy options for the management of biological invasions

&lt;p&gt;Chapter 6: Governance and policy options for the prevention and control of biological invasions of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.&lt;/p&gt;Suggested citation: McGeoch, M. A., Ordonez, A., Howard, P. L., Groom, Q. J., Shrestha, B. B., Fernandez, M., Brugnoli, E., Bwalya, B., Byun, C., Ksenofontov, S., Ojaveer, H., Simberloff, D., Mungi, N. A., and Rono, B. (2023). Chapter 6: Governance and policy options for the prevention and control of biological invasions. In: Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Roy, H. E., Pauchard, A., Stoett, P., and Renard Truong, T. (eds.). IPBES secretariat, Bonn, Germany. https://doi.org/10.5281/zenodo.743074