Antimicrobial resistance trends in clinical Escherichia coli and Klebsiella pneumoniae in Ethiopia

Background

Clinicians rely on local antimicrobial resistance pattern data to guide empiric treatment for seriously ill patients when culture and antimicrobial susceptibility testing results are not immediately available.

Objective

This study aimed to analyse 5-year trends in antimicrobial resistance profiles of Escherichia coli and Klebsiella pneumoniae isolates.

Methods

Bacteriology reports from 2017 to 2021 at the Ethiopian Public Health Institute were analysed retrospectively. Isolates were identified using either the VITEK 2 Compact system, the BD Phoenix M50 instrument, or conventional biochemical tests. Antimicrobial susceptibility testing was conducted using either the Kirby-Bauer disk diffusion method or the VITEK 2 Compact system and BD Phoenix M50 systems available at the time of testing. The Cochran Armitage trend test was employed to test the significance of antimicrobial resistance trends over time. P-values less than 0.05 were considered statistically significant.

Results

Of the 5382 bacteriology reports examined, 458 (9%) were on E. coli and 266 (5%) were on K. pneumoniae. Both K. pneumoniae (88%) and E. coli (65%) demonstrated high resistance to extended-spectrum cephalosporins. However, both K. pneumoniae (14%) and E. coli (5%) showed lower rates of resistance to carbapenems compared to other antimicrobials. In K. pneumoniae, resistance to carbapenems (from 0% to 38%; p < 0.001) and ciprofloxacin (from 41% to 90%; p < 0.001) increased significantly between 2017 and 2021.

Conclusion

Both organisms showed very high resistance to broad-spectrum antibiotics. Additionally, K. pneumoniae demonstrated a statistically significant rise in ciprofloxacin and carbapenem resistance.

What this study adds

This study emphasises the significance of regular reporting of local antimicrobial resistance patterns as this information can guide appropriate empiric therapy and efforts to address antimicrobial resistance issues.

Comparison of syndromic versus laboratory-confirmed diagnosis of Neisseria gonorrhoeae and Treponema palladium, infections at the selected health centers in Addis Ababa, Ethiopia

Background

Sexually transmitted infections (STIs) are major infectious diseases worldwide. Around one million people get STIs every day and among them a high burden of the diseases seen in Sub-Saharan African countries. In most developing countries, including Ethiopia, STIs are diagnosed only using syndromic methods, although there seems to be no consensus between syndromic and laboratory-based research.

Objective

To compare the effectiveness of a syndromic versus laboratory-based approach in the diagnosis of sexually transmitted infections, especially Neisseria gonorrhoeae (NG) and Treponema palladium (TP), infections among those attending a public health center in Addis Ababa, Ethiopia.

Methods

a cross-sectional study was conducted from April 2019 to March 2020, at selected health centers STIs clinics in Addis Ababa, Ethiopia. A total of 325 study participants were involved. From each participant after having socio-demographic data, additional blood, urethral and vaginal discharge was collected. Then serological, Gram stain, culture, and biochemical tests were performed. SPSS version 23 was used to enter and analyze data. All relevant bodies provided ethical approval, and each study participant gave written informed consent.

Results

Among the total participants 167 (51.4%) were males; 177 (54.5%) between ages of 26 and 35; and 178(54.8%) single. Of the total 325 NG, and 125 TP syndromic managed suspected cases, only 163 (50%) and 38 (30.4%) were laboratory- confirmed positive cases respectively. However, there was no statistically significant difference between NG and TP syndromic versus laboratory diagnostic confirmed cases (P-value > 0.005).

Conclusion

The present study indicated that even if, there were no statistical differences between syndromic versus Laboratory diagnosis confirmed NG and TP cases, more than half of syndromic cases could not be confirmed by laboratory diagnosed tests. Thus, to strengthen the present findings, further large-scale studies are recommended.

Distribution of Candida albicans and non-albicans Candida species isolated in different clinical samples and their in vitro antifungal suscetibity profile in Ethiopia

Background

The spectrum of yeasts and their antifungal susceptibility profile are poorly known and treatment of fungal disease has remained empirical. The aim of this study is to determine the spectrum and antifungal susceptibility profile of yeasts particularly of Candida species.

Methods

A descriptive study on the composition of Candida species and antifungal susceptibility profile were conducted from January 2018 to September 2018. Clinical samples collected from different sites were cultured on Sabouraud dextrose agar and incubated for an appropriate time. Identification of yeast isolates and their antifungal susceptibility profile were determined by the VITEK 2 compact system. Descriptive statistics such as frequency and percentage of Candida species were calculated using SPSS version 20.

Results

Of 209 yeasts recovered, 104(49.8%), 90 (43.1%), 15(7.2%) were C. albicans, non albicans Candida species, and other yeasts, respectively. Among non albicans Candida species, Candida krusei was the commonest isolate. Of other yeast groups, 66.7% was represented by Cryptococcus laurentii. Regardless of Candida species identified, 85.6, 3.9, and 10.5% of the isolates were susceptible, intermediate, and resistant to fluconazole, respectively. C krusei was 100% resistant to the drug. Voriconazole demonstrated the greatest antifungal activity against Candida isolates in which 99.4% of Candida isolates were susceptible. The susceptibility and the resistance rate of Candida isolate to both caspofungin and micafungin were the same being 96 and 4% respectively. However, micafungin was more potent than caspofungin. The susceptibility, resistant, and intermediate rates of yeasts against flucytosine were, 86.2, 6.6, and 7.2%, respectively.

Conclusions

The present study demonstrated the distribution of Candida species in different clinical specimens where the isolation rate of non-albicans Candida species was comparable to Candida albicans. The high resistance rate of C. krusei to fluconazole and flucytosine may demonstrate that the treatment of candidiasis empirically is questionable.

Population studies of Glossina pallidipes in Ethiopia: emphasis on cuticular hydrocarbons and wing morphometric analysis

Tsetse flies, like many insects, use pheromones for inter- and intra-specific communication. Several of their pheromones are cuticular hydrocarbons (CHCs) that are perceived by contact at close range. We hypothesized that for a successful implementation of the Sterile Insect Technique (SIT), along with proper identification of target area and target species, the target tsetse populations and the sterile flies must chemically communicate with each other. To study the population structuring of Glossina pallidipes in Ethiopia, CHCs were extracted and analyzed from three tsetse belts. As a comparative approach, wing morphometric analysis was performed. The analysis of the relative abundance of CHCs revealed that populations of G. pallidipes from the Rift Valley tsetse belt showed a distinct clustering compared to populations from the other two belts. The spatial pattern of CHC differences was complemented by the wing morphometric analysis. Our data suggest that CHCs of known biological and ecological role, when combined with wing morphometric data, will provide an alternative means for the study of population structuring of Glossina populations. This could aid the planning of area wide control strategies using SIT, which is dependent on sexual competence.

Association between subcutaneous white adipose tissue and serum 25-hydroxyvitamin D in overweight and obese adults

Cholecalciferol is known to be deposited in human adipose tissue, but it is not known whether 25-hydroxyvitamin D (25(OH)D) is found in detectable concentrations. Therefore, our objective was to determine whether 25(OH)D is detectable in subcutaneous white adipose tissue (SWAT) in overweight and obese persons enrolled in a twelve week energy restricted diet. Baseline and post-intervention gluteal SWAT biopsies were collected from 20 subjects participating in a larger clinical weight loss intervention. LC-MS/MS was utilized to determine SWAT 25(OH)D concentrations. Serum 25(OH)D and 1,25(OH)2D were measured by RIA. Body composition was assessed by dual energy x-ray absorptiometry. SWAT 25(OH)D concentrations were 5.8 ± 2.6 nmol/kg tissue and 6.2 ± 2.7 nmol/kg tissue pre- and post-intervention SWAT, respectively. There was a significant positive association between SWAT 25(OH)D concentration and serum 25(OH)D concentration (r = 0.52, P < 0.01). Both SWAT and serum 25(OH)D concentrations did not significantly change after a twelve-week period of energy restriction with approximately 5 kg of fat loss. In conclusion, we have demonstrated our LC-MS/MS method can detect 25(OH)D3 in human subcutaneous fat tissue from overweight and obese individuals and is consistent with previously reported concentrations in swine. Additionally, our findings of no significant changes in SWAT 25(OH)D3 or serum 25(OH)D after a 6% loss of total body weight and 13% reduction in total fat provides the first human evidence that adipose 25(OH)D does not likely contribute to serum 25(OH)D with moderate weight loss; whether this is also the case with larger amounts of weight loss is unknown. Weight loss alone is not sufficient to increase serum 25(OH)D and increases in dietary or dermal biosynthesis of vitamin D appear to be the most critical contributors to in vitamin D status.

Vitamin D(3) in fat tissue

The literature describing vitamin D content of fat tissue is extremely limited. We conducted a pilot study that measured the concentrations of vitamin D(3) in the fat tissue and serum of obese adults. These measurements were performed using a new liquid chromatography mass spectrometry (LC/MS) method. The objectives of this study were: to measure and report the vitamin D(3) concentration in serum and subcutaneous fat samples from obese individuals and to examine the association of vitamin D(3) in fat with vitamin D(3) in serum. This cross-sectional study was conducted in 17 obese men and women who were scheduled to undergo gastric bypass surgery. The mean vitamin D(3) concentration in subjects' subcutaneous fat tissue samples was 102.8 +/- 42.0 nmol/kg. The mean vitamin D(3) concentration in serum was 7.78 +/- 3.99 nmol/l. Vitamin D(3) concentrations of fat tissue and serum were positively correlated (r = 0.68, P = 0.003). Consistent with previous findings in obese subjects, subjects in this study had suboptimal vitamin D status as demonstrated by a mean 25-hydroxyvitamin D concentration of 43.3 +/- 15.4 nmol/l. In conclusion, fat tissue vitamin D(3) can be measured by LC/MS and is detectable in obese subjects with suboptimal vitamin D status. Compatible with the long-standing concept that fat tissue is a storage site for vitamin D, fat tissue and serum vitamin D(3) concentrations were positively correlated.

Properties of food folates determined by stability and susceptibility to intestinal pteroylpolyglutamate hydrolase action

The intestinal absorption of folate occurs at the monoglutamyl level, and an important measure of food folate bioavailability is how much folate from the food reaches the intestinal sites in forms that can readily be absorbed. In the absence of protecting agents, e.g., vitamin C and reduced thiols, many labile folates may be lost during cooking and during residence in the acid-peptic milieu of the stomach. On the other hand, the presence of polyglutamyl folate necessitates the action of intestinal hydrolases, which could be affected by food constituents. In this study, we developed an in vitro assay for the determination of an index of food folate availability. The index of folate availability in this study was defined as that proportion of folate that has been identified as monoglutamyl derivatives after tests for stability and susceptibility to an enzymatic hydrolysis. The index of folate availability varied widely among foods. The highest index was for egg yolk (72.2%), followed by cow's livers (55.7%), orange juice (21. 3%), cabbage (6.0%), lima beans (4.5%) and lettuce (2.9%). Yeast folate had the lowest index (0.3%). The availability indices generated by this study correlate with the indices of the bioavailability of the corresponding food folate observed in earlier studies, R2 = 0.529 (P = 0.068). Additional information is required on the bioavailability of other food products to test the usefulness of this in vitro approach for assessing food folate availability.

Responses of circulating urea cycle and branched-chain amino acids to feeding in adult and aged Fischer-344 rats

Amino acid concentrations in plasma and blood were compared between adult (6 months) and aged (22 months) male rats in fed and food-deprived (fasted) states. Since feeding is known to elevate plasma amino acids, rats were sampled after food had been freely available to them and after food was withheld for 20 hours. Fourteen amino acids increased (8 to 74%) in blood and plasma in fed rats compared to food-deprived rats. Blood concentrations of four amino acids (cystine, aspartate, threonine, and phosphoserine) were increased in aged compared to adult rats, while tyrosine was 10% lower. The interaction between fed state and age was significant for the branched-chain amino acids (BCAA) as they increased 23% in the blood and plasma of fed compared to food-deprived adult rats; however, BCAA were not affected by feeding state in the aged rats. Plasma arginine concentration was 12% lower (p < 0.001) and citrulline was 20% higher (p < 0.005) in aged compared to adult rats, and consequently the citrulline:arginine ratio was elevated by 36% in aged rats. Our results demonstrate that, although the total arginine in whole blood is not altered or is increased with aging, less of the arginine is transported in the plasma of aged compared to adult rats. Furthermore, these results indicate altered metabolism of the urea cycle amino acids and BCAA with aging in the rat.

Hyperhomocysteinemia and traditional cardiovascular disease risk factors in end-stage renal disease patients on dialysis: a case-control study

Hyperhomocysteinemia occurs frequently in end-stage renal disease (ESRD), but its prevalence in comparison with traditional cardiovascular disease (CVD) risk factors is unknown. Fasting total plasma homocysteine, potential determinants of plasma homocysteine (i.e., plasma B-vitamins and serine), total and HDL cholesterol, glucose, and creatinine, were determined in 24 ESRD patients on dialysis, and 24 age, gender, and race matched Framingham Offspring Study controls with normal renal function. Presence of clinical CVD and CVD risk factors was established by standardized methods. Mean plasma homocysteine was markedly higher in the ESRD patients versus controls (22.7 vs. 9.5 mumol/l). ESRD patients were 33 times more likely than controls to have hyperhomocysteinemia (> 15.8 mumol/l) (95% confidence interval, 5.7-189.6). Hyperhomocysteinemia persisted in the ESRD patients despite normal to supernormal B-vitamin status. Plasma serine levels below the tenth percentile of the control distribution were found in 75% of the ESRD patients. Oral serine supplementation caused a 37% increase in mean plasma serine, but had no effect on plasma homocysteine in four ESRD patients with supernormal plasma folate, low plasma serine, and hyperhomocysteinemia. Given its unusually high prevalence, improved management of hyperhomocysteinemia might reduce CVD sequelae in ESRD.

Effects of choline deficiency and methotrexate treatment upon liver folate content and distribution

We examined the effects of feeding rats a choline deficient diet, of treating rats with low doses of methotrexate (MTX, 0.1 mg/kg, daily), and of combined choline deficiency and MTX treatment upon the content and distribution of folates in liver. We used a newly devised technique for analysis of folates which utilized affinity chromatography followed by high pressure liquid chromatography. Compared to control rats, total hepatic folate content decreased by 31% in the choline deficient rats, by 48% in the MTX treated rats, and by 60% in rats which were both choline deficient and treated with MTX. In extracts of livers from control rats, folates were present predominantly as penta (35%) and hexaglutamyl (52%) derivatives. The pteridine ring structure distribution of these folates was as follows: 48% 5-methyltetrahydrofolate, 14% formylated tetrahydrofolate, and 39% tetrahydrofolate. In choline deficient animals, there was a decrease in the relative concentration of pentaglutamyl folates and an increase in the relative concentration of heptaglutamyl folates. In livers from MTX treated animals, MTX-polyglutamates with 2-5 glutamate residues accumulated. The consequences of MTX treatment were: a) an elongation of the glutamate chains of the folates as the proportion of hepta- and octaglutamyl derivatives was increased relative to penta- and hexaglutamyl folates; b) the occurrence of unreduced folic acid; c) a decrease in the relative concentration of 5-methyltetrahydrofolate and an increase in the relative concentration of formylated tetrahydrofolate, and d) no change in the relative concentrations of tetrahydrofolate. In livers from animals that were both choline deficient and treated with MTX, the tetrahydrofolate concentrations were 50% of control while formylated tetrahydrofolate concentrations increased 3-fold. These data are discussed from the standpoint of the current understanding of mechanisms that regulate the elongation of the glutamic acid chains of folates and those that regulate folate dependent synthesis and utilization of one carbon unit.

Chloroquine in the treatment of porphyria cutanea tarda

Porphyria cutanea tarda (PCT) is common in Ethiopia and invariably affects the liver. Treatment by abstension from alcohol and avoidance of direct sunlight often failed to achieve lasting improvement. Phlebotomy is unacceptable to most of our patients and impractical as a routine therapy. Chloroquine phosphate 500 mg (300 mg base) given daily for 10 days to 24 patients with confirmed PCT, was found to be uniformly effective. Both clinical and biochemical remissions were complete, The side effects of chloroquine include fever, nausea, vomiting and myalgia which predictably occur on the third day of therapy and subside within 72 hours. Since all other modes of therapy are ineffective or impractical and since the response to chloroquine is prompt, effective and reproducible and the side effects are brief, mild and do not cause permanent hepatic damage, it is suggested that this drug is currently the most practical treatment for PCT in areas where repeated phlebotomy is unacceptable and patient follow-up is unsatisfactory.

Porphyria cutanea tarda in Ethiopia

The clinical, biochemical and histological features of 75 Ethiopians with porphyria cutanea tarda (PCT) are described. PCT in Ethiopia is definitely related to alcohol abuse and there is no clinical evidence for hereditary predisposition. Significant elevation of transaminases and bromsulphthalein retention, moderate to marked hepatic siderosis and inflammation with little or no fibrosis, suggestive of mild or likely reversible parenchymal changes, characterize the liver affection in these patients. A similar study of 18 patients with hyperpigmentation of the face and hands but without blisters, an unexplained but common feature of liver disease in Ethiopia, revealed that serum iron and urinary uroporphyrin levels were normal in eight but significantly elevated in ten (56%). Neither elevated serum iron and hepatic siderosis nor increased urinary uroporphyrin completely explains the hyperpigmentation in this group of patients.

Hyperpigmentation of the face and hands without blisters: porphyria cutanea tarda

Hyperpigmentation of the face and hands without blisters and hypertrichosis in Ethiopian patients with liver disease represents an early or latent form of porphyria cutanea tarda.