Doxycycline as an antimalarial : Impact on travellers’ diarrhoea and doxycycline resistance among various stool bacteria – Prospective study and literature review

Publisher Copyright: © 2022 The AuthorsBackground: Antibiotics predispose travellers to acquire multidrug-resistant bacteria, such as extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE). Although widely used in antimalarial prophylaxis, doxycycline has scarcely been studied in this respect. Methods: We explored the impact of doxycycline on rates of traveller's diarrhoea (TD), ESBL-PE acquisition and, particularly, doxycycline co-resistance among travel-acquired ESBL-PE in a sample of 412 visitors to low- and middle-income countries. We reviewed the literature on traveller studies of doxycycline/tetracycline resistance among stool pathogens and the impact of doxycycline on TD rates, ESBL-PE acquisition, and doxycycline/tetracycline resistance. Results: The TD rates were similar for doxycycline users (32/46; 69.6%) and non-users (256/366; 69.9%). Of the 90 travel-acquired ESBL-PE isolates, 84.4% were co-resistant to doxycycline: 100% (11/11) among users and 82.3% (65/79) among non-users. The literature on doxycycline's effect on TD was not conclusive nor did it support a recent decline in doxycycline resistance. Although doxycycline did not increase ESBL-PE acquisition, doxycycline-resistance among stool pathogens proved more frequent for users than non-users. Conclusions: Our prospective data and the literature review together suggest the following: 1) doxycycline does not prevent TD; 2) doxycycline use favours acquisition of doxy/tetracycline-co-resistant intestinal bacteria; 3) although doxycycline does not predispose to travel-related ESBL-PE acquisition per se, it selects ESBL-PE strains co-resistant to doxycycline; 4) doxycycline resistance rates are high among stool bacteria in general with no evidence of any tendency to decrease.Peer reviewe

Fluoroquinolone antibiotic users select fluoroquinolone-resistant ESBL-producing Enterobacteriaceae (ESBL-PE) - Data of a prospective traveller study

Background: One third of travellers to the poor regions of the (sub) tropics become colonized by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Co-resistance to non-betalactam antibiotics complicates the treatment of potential ESBL-PE infections. Methods: We analysed co-resistance to non-beta-lactams among travel-acquired ESBL-PE isolates of 90 visitors to the (sub) tropics with respect to major risk factors of colonization: destination, age, travellers' diarrhoea (TD) and antibiotic (AB) use. Results: Of the ESBL-PE isolates, 53%, 52%, 73%, and 2% proved co-resistant to ciprofloxacin, tobramycin, co-trimoxazole, and nitrofurantoin, respectively. The rates were similar among those with (TD+) or without (TD-) travellers' diarrhoea. Among fluoroquinolone-users vs. AB non-users, the co-resistance rates for ciprofloxacin were 95% versus 37% (p = 0.001), for tobramycin 85% versus 43% (p = 0.005), co-trimoxazole 85% versus 68% (p = 0.146), and nitrofurantoin 5% versus 2% (p = 0.147). In multivariable analysis co-resistance to ciprofloxacin was associated with increasing age, fluoroquinolone use, and tobramycin resistance. Conlusions: While TD predisposes to ESBL-PE non-selectively, antimicrobial use favours strains resistant to drug taken and, simultaneously, any drug with resistance genetically linked to the drug used. Antibiotics taken during travel predispose to ESBL-PE with a high co-resistance rate. (C) 2017 The Author(s). Published by Elsevier Ltd.Peer reviewe

Increased Risk for ESBL-Producing Bacteria from Co-administration of Loperamide and Antimicrobial Drugs for Travelers' Diarrhea

Peer reviewe

Bacterial, viral and parasitic pathogens analysed by qPCR: Findings from a prospective study of travellers' diarrhoea

Background: The diagnostics of travellers' diarrhoea (TD) has been revolutionised by multiplex qPCR assays. While mostly of bacterial aetiology, viruses and parasites account for the disease among 10-20% of travellers. Despite this, prospective studies applying qPCR assays remain scarce that cover not only bacteria, such as the various diarrhoeagenic Escherichia coli (DEC), but also viral and parasitic pathogens. Method: We analysed by qPCR pre- and post-travel stool samples of 146 Finnish travellers for bacterial, viral and parasitic pathogens: enteropathogenic (EPEC), enteroaggregative (EAEC), enterotoxigenic (ETEC), enterohaemorrhagic (EHEC), and enteroinvasive (EIEC) E. coli; Shigella, Campylobacter, Salmonella, Yersinia and Vibrio cholerae; norovirus G1 and G2, rotavirus, enteroviruses, and sapovirus; and Giardia lamblia, Entamoeba histolytica, and Cryptosporidium. Symptoms and medication data during travel were collected by questionnaires. Results: We detected bacterial pathogens in 102/146 samples (69.9%; EAEC, EPEC, ETEC most common), viral ones in 13 (8.9%; norovirus most common), and parasitic ones in one (0.7%; Giardia). Noroviruses were associated with severe symptoms (23.5% versus non-severe 4.9%). In the TD group, 41.7% (5/12) of those with viral pathogens (vs. 13.3%; 11/83 without) took antibiotics. Conclusion: Viral pathogens, particularly noroviruses, prevail in severe TD. The symptoms of viral disease are often severe and lead to unwarranted use of antibiotics.Peer reviewe

Multiplex PCR detection of Cryptosporidium sp, Giardia lamblia and Entamoeba histolytica directly from dried stool samples from Guinea-Bissauan children with diarrhoea

Background: In developing countries, diarrhoea is the most common cause of death for children under five years of age, with Giardia lamblia, Cryptosporidium and Entamoeba histolytica as the most frequent pathogenic parasites. Traditional microscopy for stool parasites has poor sensitivity and specificity, while new molecular methods may provide more accurate diagnostics. In poor regions with sample storage hampered by uncertain electricity supply, research would benefit from a method capable of analysing dried stools. Methods: A real-time multiplex PCR method with internal inhibition control was developed for detecting Giardia lamblia, Cryptosporidium hominis/parvum and Entamoeba histolytica directly from stool specimens. Applicability to dried samples was checked by comparing with fresh ones in a small test material. Finally, the assay was applied to dried specimens collected from Guinea-Bissauan children with diarrhoea. Results: The PCR's analytical sensitivity limit was 0.1 ng/ml for G. lamblia DNA, 0.01 ng/ml for E. histolytica DNA and 0.1 ng/ml for Cryptosporidium sp. In the test material, the assay performed similarly with fresh and dried stools. Of the 52 Guinea-Bissauan samples, local microscopy revealed a parasite in 15%, while PCR detected 62% positive for at least one parasite: 44% of the dried samples had Giardia, 23% Cryptosporidium and 0% E. histolytica. Conclusions: Our new multiplex real-time PCR for protozoa presents a sensitive method applicable to dried samples. As proof of concept, it worked well on stools collected from Guinea-Bissauan children with diarrhoea. It provides an epidemiological tool for analysing dried specimens from regions poor in resources.Peer reviewe

Assessment of blood cultures and antibiotic susceptibility testing for bacterial sepsis diagnosis and utilization of results by clinicians in Benin: A qualitative study

ObjectivesWe assessed the current status of blood culture and antibiotic susceptibility testing (AST) practices in clinical laboratories in Benin, and how the laboratory results are used by physicians to prescribe antibiotics.MethodsThe qualitative study covered twenty-five clinical laboratories with a bacteriology unit and associated hospitals and pharmacies. Altogether 159 laboratory staff, physicians and pharmacists were interviewed about their perceptions of the state of laboratory diagnostics related to sepsis and the use of antibiotics. Face-to-face interviews based on structured questionnaires were supported by direct observations when visiting five laboratories in across the country.ResultsOnly 6 laboratories (24%) conducted blood cultures, half of them with a maximum of 10 samples per month. The most common gram-negative bacteria isolated from blood cultures were: Escherichia coli, Salmonella spp. and Salmonella enterica serovar Typhi while the most common gram-positives were Enterococcus spp. and Staphylococcus aureus. None of the laboratories listed Klebsiella pneumoniae among the three most common bacteria isolated from blood cultures, although other evidence indicates that it is the most common cause of sepsis in Benin. Due to limited testing capacity, physicians most commonly use empirical antibiotic therapy.ConclusionsMore resources are needed to develop laboratory testing capacity, technical skills in bacterial identification, AST, quality assurance, and communication of results must be strengthened

Assessment of blood cultures and antibiotic susceptibility testing for bacterial sepsis diagnosis and utilization of results by clinicians in Benin: A qualitative study

ObjectivesWe assessed the current status of blood culture and antibiotic susceptibility testing (AST) practices in clinical laboratories in Benin, and how the laboratory results are used by physicians to prescribe antibiotics.MethodsThe qualitative study covered twenty-five clinical laboratories with a bacteriology unit and associated hospitals and pharmacies. Altogether 159 laboratory staff, physicians and pharmacists were interviewed about their perceptions of the state of laboratory diagnostics related to sepsis and the use of antibiotics. Face-to-face interviews based on structured questionnaires were supported by direct observations when visiting five laboratories in across the country.ResultsOnly 6 laboratories (24%) conducted blood cultures, half of them with a maximum of 10 samples per month. The most common gram-negative bacteria isolated from blood cultures were: Escherichia coli, Salmonella spp. and Salmonella enterica serovar Typhi while the most common gram-positives were Enterococcus spp. and Staphylococcus aureus. None of the laboratories listed Klebsiella pneumoniae among the three most common bacteria isolated from blood cultures, although other evidence indicates that it is the most common cause of sepsis in Benin. Due to limited testing capacity, physicians most commonly use empirical antibiotic therapy.ConclusionsMore resources are needed to develop laboratory testing capacity, technical skills in bacterial identification, AST, quality assurance, and communication of results must be strengthened.Peer reviewe

Despite Predominance of Uropathogenic/Extraintestinal Pathotypes Among Travel-acquired Extended-spectrum β-Lactamase-producing Escherichia coli, the Most Commonly Associated Clinical Manifestation Is Travelers' Diarrhea

Background. One-third of the 100 million travelers to the tropics annually acquire extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE), with undefined clinical consequences. Methods. Symptoms suggesting Enterobacteriaceae infections were recorded prospectively among 430 Finnish travelers, 90 (21%) of whom acquired ESBL-PE abroad. ESBL-PE isolates underwent polymerase chain reaction-based detection of diarrheagenic Escherichia coli (DEC) pathotypes (enteroaggregative E. coli [EAEC], enteropathogenic E. coli [EPEC], enterotoxigenic E. coli [ETEC], enteroinvasive E. coli, and Shiga toxin-producing E. coli), and extraintestinal pathogenic/uropathogenic E. coli (ExPEC/UPEC). Laboratory-confirmed ESBL-PE infections were surveyed 5 years before and after travel. Results. Among the 90 ESBL-PE carriers, manifestations of Enterobacteriaceae infection included travelers' diarrhea (TD) (75/90 subjects) and urinary tract infection (UTI) (3/90). The carriers had 96 ESBL-producing E. coli isolates, 51% exhibiting a molecular pathotype: 13 (14%) were DEC (10 EAEC, 2 EPEC, 1 ETEC) (12 associated with TD) and 39 (41%) ExPEC/UPEC (none associated with UTI). Of ESBL-PE, 3 (3%) were ExPEC/UPEC-EAEC hybrids (2 associated with diarrhea, none with UTI). Potential ESBL-PE infections were detected in 15 of 90 subjects (17%). The 10-year medical record survey identified 4 laboratory-confirmed ESBL-PE infections among the 430 travelers, all in subjects who screened ESBL-PE negative after returning home from their index journeys but had traveled abroad before their infection episodes. Conclusions. Half of all travel-acquired ESBL-producing E. coli strains qualified molecularly as pathogens. Extraintestinal and uropathogenic pathotypes outnumbered enteric pathotypes (41% vs 14%), yet the latter correlated more closely with symptomatic infection (0% vs 92%). Despite more ESBL-PE strains qualifying as ExPEC/UPEC than DEC, travel-acquired ESBL-PE are more often associated with TD than UTI.Peer reviewe

Rapid Molecular Characterization of Acinetobacter baumannii Clones with rep-PCR and Evaluation of Carbapenemase Genes by New Multiplex PCR in Hospital District of Helsinki and Uusimaa

Peer reviewe

A 10-Minute “Mix and Read” Antibody Assay for SARS-CoV-2

Accurate and rapid diagnostic tools are needed for management of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Antibody tests enable detection of individuals past the initial phase of infection and help examine vaccine responses. The major targets of human antibody response in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the spike glycoprotein (SP) and nucleocapsid protein (NP). We have developed a rapid homogenous approach for antibody detection termed LFRET (protein L-based time-resolved Förster resonance energy transfer immunoassay). In LFRET, fluorophore-labeled protein L and antigen are brought to close proximity by antigen-specific patient immunoglobulins of any isotype, resulting in TR-FRET signal. We set up LFRET assays for antibodies against SP and NP and evaluated their diagnostic performance using a panel of 77 serum/plasma samples from 44 individuals with COVID-19 and 52 negative controls. Moreover, using a previously described SP and a novel NP construct, we set up enzyme linked immunosorbent assays (ELISAs) for antibodies against SARS-CoV-2 SP and NP. We then compared the LFRET assays with these ELISAs and with a SARS-CoV-2 microneutralization test (MNT). We found the LFRET assays to parallel ELISAs in sensitivity (90–95% vs. 90–100%) and specificity (100% vs. 94–100%). In identifying individuals with or without a detectable neutralizing antibody response, LFRET outperformed ELISA in specificity (91–96% vs. 82–87%), while demonstrating an equal sensitivity (98%). In conclusion, this study demonstrates the applicability of LFRET, a 10-min “mix and read” assay, to detection of SARS-CoV-2 antibodies