Treatment seeking behaviours, antibiotic use and relationships to multi-drug resistance: A study of urinary tract infection patients in Kenya, Tanzania and Uganda

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviour, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Using data from 6,388 patients, we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Among those with microbiologically confirmed UTI (n = 1,946), we used logistic regression to assess the relationship between treatment seeking behaviour, AB use, and the likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathway for UTI-like symptoms in this sample involved attending health facilities, rather than other providers like drug sellers. Patients from sites in Tanzania and Uganda, where over 50% of patients had an MDR UTI, were more likely to report treatment failures, and have repeat visits to providers than those from Kenyan sites, where MDR UTI proportions were lower (33%). There was no strong or consistent relationship between individual AB use and likelihood of MDR UTI, after accounting for country context. The results highlight the hurdles East African patients face in accessing effective UTI care. These challenges are exacerbated by high rates of MDR UTI, suggesting a vicious cycle of failed treatment attempts and sustained selection for drug resistance. Whilst individual AB use may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of variations in ABR.

Treatment seeking behaviours, antibiotic use and relationships to multi-drug resistance: A study of urinary tract infection patients in Kenya, Tanzania and Uganda

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviours, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from 6,827 adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Among 6,388 patients we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Of those with microbiologically confirmed UTI (n=1,946), we used logistic regression to assessed the relationship between treatment seeking behaviour, AB use, and likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathways for UTI-like symptoms included attending health facilities, rather than other providers (e.g. drug sellers). Patients from the sites sampled in Tanzania and Uganda, where prevalence of MDR UTI was over 50%, were more likely to report treatment failures, and have repeated visits to clinics/other providers, than those from Kenyan sites, where MDR UTI rates were lower (33%). There was no strong or consistent relationship between individual AB use and risk of MDR UTI, after accounting for country context. The results highlight challenges East African patients face in accessing effective UTI treatment. These challenges increase where rates of MDR UTI are higher, suggesting a reinforcing circle of failed treatment attempts and sustained selection for drug resistance. Whilst individual behaviours may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of ABR.

Studies on the uptake and release of fluoroquinolones by disposable contact lenses

PURPOSE

To evaluate the ability of three types of disposable contact lenses to take up and release three kinds of fluoroquinolones in vitro.

METHODS

We evaluated three FDA-approved disposable soft contact lenses (1-Day Acuvue, Medalist, and 14UV) for their ability to absorb and release three kinds of fluoroquinolones. Contact lenses were presoaked in fluoroquinolones for 1, 4, and 24 hours, and the uptake was determined by measuring the concentration of fluoroquinolones in the three types of disposable soft contact lenses by high pressure liquid chromatography (HPLC). After uptake, the lenses were placed in fresh saline baths, and release rates from the lenses were determined by measuring the concentration of fluoroquinolones in the saline baths by HPLC.

RESULTS

The disposable soft contact lens with the highest uptake of fluoroquinolones was the 1-Day Acuvue. After presoaking, drug concentrations in the 1-Day Acuvue and Medalist were higher than their theoretical saturation concentrations (i.e., the concentration of the fluoroquinolone eye drops [0.3%]). The release rates from the 1-Day Acuvue and Medalist lenses were slower than for the 14 UV lens.

CONCLUSIONS

These results indicate that among the lenses tested, the most practical drug delivery system is the 1-Day Acuvue disposable soft contact lens.

Identification of a mutated DNA ligase IV gene in the X-ray-hypersensitive mutant SX10 of mouse FM3A cells

The mouse carcinoma cell line SX10 is a hypersensitive mutant to x-rays and bleomycin. An earlier complementation test suggests that SX10 would belong to x-ray-cross complementing group (XRCC) 4. However, in this study, a human XRCC4 expression vector failed to complement the SX10 phenotype. Consistent with the previous report, SX10 showed the same level of DNA-dependent protein kinase activity as the wild-type SR-1. We isolated and analyzed hybrids between SX10 and human diploid fibroblast cells and found that human chromosome 13 conferred the x-ray resistance to the hybrids, suggesting that a candidate gene would be located on this chromosome. Polymerase chain reaction analysis with these hybrids and x-ray-resistant transformants obtained by introducing human chromosomes into SX10 indicated that the mutant was likely to be defective in DNA ligase IV. Sequence analysis of the DNA ligase IV gene confirmed that a defect in SX10 was attributed to a transition of G to A at nucleotide position 1413 of the gene, leading to an amino acid substitution from Trp at residue 471 to a stop codon. Revertant clones (Rev1-3) derived from SX10 showed a restored x-ray resistance; Rev1 reverted to the original nucleotide G at position 1413, whereas Rev2 and Rev3 to C. Transfection of a mouse DNA ligase IV cDNA vector into SX10 restored the resistance to both x-rays and bleomycin. SX10 showed a reduced frequency of chromosomal integration of transfected DNA, but the revertants restored the frequency found in the wild-type cells. These results suggest a possible involvement of DNA ligase IV in the integration event of foreign DNA as well as a crucial role in DNA double-strand break repair.

A novel UDP-sugar, UDP-3-ketoglucosamine or UDP-4-ketoglucosamine, from bovine heart muscle reduces metmyoglobin with NAD(P)H

3-Ketoglucose and similar ketosugars have been identified in microorganisms only and little is known about their functions. UDP-sugars are widely found as an intermediate in sugar metabolism in living organisms. Yet what role UDP-sugars play, or whether they play a direct role in metabolism, is still unknown. UDP-sugars were isolated and purified from bovine heart muscle, and a UDP-sugar fraction capable of NAD(P)H-dependent catalytic reduction of metmyoglobin was detected. Subsequent identification revealed that the active UDP-sugar was UDP-3- or UDP-4-ketoglucosamine. These compounds were purified from bovine cardiac muscle by ultrafiltration, anion-exchange column chromatography and reverse-phase chromatography. They were further characterized by determination of their chemical reducing activity, by comparison with synthetic UDP-3- or UDP-4-ketoglucosamine standards using high-performance liquid chromatography, by estimation of molecular mass using fast atom bombardment mass spectrometry, and by Fourier transform infrared microspectroscopy and electron probe microanalysis. The results suggest that UDP-3- or UDP-4-ketoglucosamine reduces metmyoglobin in bovine cardiac muscle. It is important that the reducing activity displayed by this ketosugar is not the effect of UDP-3- or UDP-4-ketoglucosamine alone but depends on NAD(P)H. In other words, this action of UDP-3- or UDP-4-ketoglucosamine is catalytic.

Acute retinal necrosis syndrome associated with herpes simplex keratitis

BACKGROUND

Although acute retinal necrosis (ARN) syndrome is caused by a herpes group virus, association of herpetic keratitis with ARN syndrome is uncommon. A case of unilateral ARN syndrome with herpes simplex keratitis is discussed.

METHODS

A 40-year-old man developed unilateral keratitis, necrotic retinitis, retinal vasculitis, vitritis, and iritis consistent with ARN syndrome 1 month after treatment for ipsilateral facial nerve palsy and auricular herpetic vesicles (Tolosa-Hunt syndrome). Impression cytologic examination of the corneal epithelial ulcer that developed concurrent with the intraocular findings and of the aqueous humor (obtained by paracentesis) was performed.

RESULTS

Cells that reacted with anti-herpes simplex virus type 1 (HSV-1) antibody were detected on impression cytology, and DNA fragments corresponding to the HSV-1 DNA sequence were detected in the aqueous humor.

CONCLUSION

This case shows that ARN syndrome may, on rare occasions, be associated with herpes keratitis secondary to HSV-1.

An atypical Leber's hereditary optic neuropathy with the 11778 mutation

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Triacylglycerol lipase-mediated release of arachidonic acid for renal medullary prostaglandin synthesis

The effect of triacylglycerol lipase or triarachidonin on the synthesis of prostaglandin E2 in rabbit kidney medulla slices was examined. Prostaglandin E2 generation was enhanced by exogenous triacylglycerol lipase, indicating that arachidonic acid released from medullary triacylglycerols is readily available for prostaglandin biosynthesis. Triarachidonin stimulated prostaglandin E2 production in a dose-dependent manner. Moreover, the kidney medulla slices showed triacylglycerol lipase activity using trimargarin as substrate. The addition of mepacrine made the stimulatory effect of triarachidonin on prostaglandin E2 formation more pronounced. Studies utilizing EGTA and p-bromophenacyl bromide revealed that triacylglycerol lipase of kidney medulla is independent of Ca2+ and sensitive to a sulfhydryl inhibitor. These results suggest the presence of triacylglycerol lipase and triacylglycerol as a possible candidate for providing free arachidonic acid to cyclooxygenase in kidney medulla.