4 research outputs found
Antimicrobial resistance pattern of methicillin-resistant Staphylococcus aureus isolated from sheep and humans in Veterinary Hospital Maiduguri, Nigeria
No full textBACKGROUND AND AIM: Methicillin-resistant Staphylococcus aureus (MRSA), an important opportunistic pathogen, is a Gram-positive coccus known to be resistant to β-lactam antibiotics. Its virulence depends on a large range of factors, mainly extracellular proteins, such as enzymes and exotoxins, that contribute to causing a wide range of diseases in human and animal species. The major reasons for the success of this pathogen are its great variability, which enables it to occur and thrive at different periods and places with diverse clonal types and antibiotic resistance patterns within regions and countries. Infections caused by antibiotic-resistant S. aureus bring about serious problems in the general population (humans and animals). Infections with these pathogens can be devastating, particularly for the very young, adults and immunocompromised patients in both humans and animals. This study aimed to determine the presence of MRSA in both apparently healthy and sick sheep brought to the veterinary hospital as well as veterinary staff and students on clinical attachment in the hospital. MATERIALS AND METHODS: A total of 200 nasal swab samples were collected aseptically from sheep and humans (100 each) for the isolation of MRSA. The samples were processed by appropriately transporting them to the laboratory, then propagated in nutrient broth at 37°C for 24 h followed by subculturing on mannitol salt agar at 37°C for 24 h, to identify S. aureus. This was followed by biochemical tests (catalase and coagulase tests) and Gram staining. MRSA was isolated using Clinical Laboratory Standard Institute (CLSI) guideline and confirmed by plating onto Oxacillin (OX) Resistance Screening Agar Base agar. The antimicrobial susceptibility pattern of the MRSA isolates was determined using the disk diffusion method against 12 commonly used antimicrobial agents. RESULTS: The total rate of nasal carriage of S. aureus and MRSA was found to be 51% and 43% in sheep and humans, respectively. The MRSA prevalence in male and female sheep was 18% and 8%, while 9% and 8% were for male and female human samples, respectively. The antimicrobial susceptibility test showed 100% resistance to OX, cefoxitin, oxytetracycline, cephazolin, and penicillin-G (Pen) by MRSA isolates from humans. Conversely, there was 100% susceptibility to ciprofloxacin, imipenem, and gentamicin; for linezolid (LZD), it was 87.5%, norfloxacin (NOR) (71%), and erythromycin (ERY) (50%) susceptibility was recorded. The MRSA isolates from sheep recorded 100% resistance to the same set of drugs used for human MRSA isolates and were equally 100% susceptible to gentamicin, imipenem, LZD, ciprofloxacin, NOR (92%), and ERY (50%). CONCLUSION: This study determined the presence of MRSA in sheep and humans from the Veterinary Hospital, Maiduguri. It appears that certain drugs such as ciprofloxacin, imipenem, and gentamicin will continue to remain effective against MRSA associated with humans and sheep. Reasons for the observed patterns of resistance must be explored to reduce the burdens of MRSA resistance. Furthermore, the present study did not confirm the MRSA resistance genes such as mecA and spa typing to ascertain the polymorphism in the X-region using appropriate molecular techniques. Hence more studies need to be conducted to elucidate these findings using robust techniques
Molecular genotyping in a malaria treatment trial in Uganda - unexpected high rate of new infections within 2 weeks after treatment.
No full textPolymerase chain reaction (PCR) genotyping of malaria parasites in drug efficacy trials helps differentiate reinfections from recrudescences. A combination therapy trial of one (n = 115) or three (n = 117) days artesunate (1AS, 3AS 4 mg/kg/day) plus sulphadoxine-pyrimethamine (SP) vs. SP alone (n = 153) was conducted in Mbarara, a mesoendemic area of western Uganda. All paired recurrent Plasmodium falciparum parasitaemias on days 7, 14, 21 and 28 post-treatment were genotyped by PCR amplification and analysis of glutamate-rich protein (glurp) and merozoite surface proteins (msp) 1 and 2 genes to distinguish recrudescent from new infections. A total of 156 (1AS = 61, 3AS = 35, SP alone = 60) of 199 paired recurrent samples were successfully analysed and were resolved as 79 recrudescences (1AS = 32, 3AS = 8, SP = 39) and 77 as new infections (1AS = 29, 3AS = 27, SP = 21). The ratios of proportions of new to recrudescent infections were 0.2, 0.9, 1.4 and 1.9 on days 7, 14, 21 and 28, respectively (P < 0.001, chi(2) test for linear trend). Unexpected high new infection rates were observed early in follow-up on days 7 [5/26 (19.2%)] and 14 [24/51 (47.1%)]. These results impact significantly on resistance monitoring and point to the value of genotyping all recurrent infections in antimalarial trials
Fatty acids and their metabolism critically regulate podocyte survival
No full textDiabetic nephropathy (DN) is the most common cause of end-stage renal disease in industrialized countries, and most affected patients have type 2 diabetes. Podocyte injury and loss are considered critical in the development, and progression of DN. Several factors of the diabetic milieu are well known to impair function and survival of podocytes. However, the role of free fatty acids (FFAs), which are elevated in type 2 diabetes, and the role of their metabolism are just emerging in the pathogenesis of DN. FFAs were reported to regulate podocyte survival. Saturated FFAs, i.e. palmitic acid, were found to induce endoplasmic reticulum (ER) stress and podocyte death, whereas monounsaturated FFAs, i.e. palmitoleic acid or oleic acid, were protective.
The aims of the present study were to investigate whether FFA metabolism is regulated in glomeruli of type 2 diabetic patients with DN and whether regulation of FFA metabolism affects the susceptibility of podocytes towards palmitic acid. Particularly, I aimed to investigate whether regulation of fatty acid oxidation (FAO) modifies palmitic acid-induced podocyte death. As genome wide association studies suggest that acetyl CoA carboxylase (ACC) 2, an important enzyme in the regulation of FAO, is involved in the pathogenesis of DN, I performed detailed studies investigating the role of ACCs in podocytes. Furthermore, I explored the effect of palmitic acid on podocytes in combination with well-known proapoptotic stimuli of the diabetic milieu.
The present study uncovered that palmitic acid can aggravate the toxicity of other factors which are known to be important in the pathogenesis of DN and which are considered to cause podocyte loss. In particular the toxicity of high glucose concentrations and transforming growth factor (TGF)-β are substantially increased by palmitic acid, whereas the effect of palmitic acid on tumor necrosis factor (TNF)-α induced podocyte death is discret.
In the main part of this study FFA metabolism and its effect on palmitic acid induced podocyte death was investigated. The study finds that in glomeruli of type 2 diabetic patients mRNA expression levels of several key enzymes involved in fatty acid metabolism are altered. Of particular relevance for my detailed studies on FAO, a significant upregulation of all three isoforms of carnitine palmitoyltransferase (CPT)-1, the rate-limiting enzyme for FAO, and a downregulation of ACC-2, which catalyzes the formation of the CPT-1 inhibitor malonyl-CoA, are found which suggest a disposition for increased FAO. In vitro, stimulation of FAO by aminoimidazole-4-carboxamide-1β-D-ribofuranoside (Aicar) or by adiponectin, activators of the low-energy sensor AMP-activated protein kinase (AMPK), protect from palmitic acid induced podocyte death. Conversely, inhibition of CPT-1, a downstream target of AMPK, by etomoxir augments palmitic acid toxicity and impedes the protective Aicar effect. Etomoxir blocked the Aicar induced FAO measured with tritium labeled palmitic acid. Of note, only double knockdown of ACC1 and ACC2 has a protective effect on palmitic acid induced cell death, which indicates that both isoforms contribute to the regulation of FAO in podocytes. Furthermore, the effect of Aicar is associated with a reduction of ER-stress as indicated by a significant attenuation of the palmitic acid induced upregulation of immunoglobulin heavy chain binding protein (BiP), an ER chaperone, and of the proapoptotic transcription factor C/EBP homologous protein (CHOP).
In conclusion, palmitic acid increases the toxicity of other factors known to contribute to podocyte loss, which underlines the potentially important contribution of elevated saturated FFAs in the pathogenesis of DN. An important role of FFAs and of their metabolism in the pathogenesis of DN is further suggested by profound changes in gene expression levels of key enzymes of FFA metabolism in glomerular extracts of type 2 diabetic patients. The changed expression profile indicates a compensatory, protective response. Moreover, the results of this study uncover that stimulation of FAO by modulating the AMPK-ACC-CPT-1 pathway protects from palmitic acid induced podocyte death. The results of this study should encourage further investigations to evaluate the therapeutic potential of interfering with FFA metabolism specifically with stimulating FAO for the prevention and therapy of DN
A New Form of Authoritarianism? Rethinking Military Politics in Post-1999 Nigeria
No full textDespite the vast research that has been done on the Nigerian military, virtually all of these studies have failed to critically examine the accepted role of the military in the democratising phase. This is important because the relationship between the political elite and the military in post-military authoritarian states guarantees either democratic consolidation, or its reversal. In Nigeria, despite an appearance of significant progress in subordinating the military institution to democratic civilian authority, the military remains a crucial political actor in the polity. It appears that the military has yet to accept the core democratic principles of civilian oversight of the institution. This thesis, therefore, explores whether a new form of military authoritarianism is emerging in Nigeria, with the aim of understanding Nigeria’s military behaviour in a transitional phase, from prolonged military authoritarianism to democratisation. To examine this military behaviour, Alfred Stepan’s concept of military prerogatives that was used to understand the military’s behaviour in a transitional phase in Latin America is applied to Nigeria.
A crucial understanding of authoritarianism in Nigeria is initially discussed in this study using mainly document analysis strategy to examine whether multi-ethnic states, such as Nigeria, tend to have authoritarian systems. Six hypotheses form the core analysis of this thesis: first, that the military has retained significant military prerogatives; second, that retired military officers are gaining influential political and economic positions; third, autonomous military involvement in human rights abuses since 1999; and fourth, that civilian government oversight remains weak, and facilitates military authoritarianism. These hypotheses are primarily analysed using the elite interview technique. During the first half of 2011, the author conducted field research where serving and retired military officers were interviewed. The fifth hypothesis is that the military has intervened in politics post-1999. The examination of this hypothesis relies primarily on key security-related media reports (mostly newspaper editorials) on the military after 1999. The examination of the final hypothesis, that increases in military expenditures might facilitate a new form of military authoritarianism, relies primarily on descriptive statistical analysis. In addition, this study collated relevant historical materials that relate to the military, utilising national archival collections.
The empirical findings of this research did not identify a new form of military authoritarianism in Nigeria. The study, however, argues that the unrestricted institutional framework accorded the military has contributed significantly to authoritarian practices in the post-military era in Nigeria. This study discovered that there were similarities between the Brazilian and Nigerian militaries in regard to their military spending during their period in power. Both countries had lower defence budgets. Just as in Brazil, it appears that part of the reason the Nigerian military decided to relinquish power in 1999 had to do with its desire to gain a higher budget, something that was precluded in a military government struggling to retain a sense of legitimacy. The military needed a higher budget to modernise and re-professionalise its institution after more than a decade in power. This feature, which the Nigerian military shares with the Brazilian military, appears to justify the application to Nigeria of Alfred Stepan’s concept of military prerogatives.
