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result(s) for
"Kostyanev, Tomislav"
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International and regional spread of carbapenem-resistant Klebsiella pneumoniae in Europe
2024
Carbapenem-resistant
Klebsiella pneumoniae
(CRKP) are of particular concern due to the spread of antibiotic resistance genes associated with mobile genetic elements. In this study, we collected 687 carbapenem-resistant strains recovered among clinical samples from 41 hospitals in nine Southern European countries (2016-2018). We identified 11 major clonal lineages, with most isolates belonging to the high-risk clones ST258/512, ST101, ST11, and ST307.
bla
KPC-like
was the most prevalent carbapenemase-encoding gene (46%), with
bla
OXA-48
present in 39% of isolates. Through the combination and comparison of this EURECA collection with the previous EuSCAPE collection (2013-2014), we investigated the spread of high-risk clones circulating in Europe exhibiting regional differences. We particularly found
bla
KPC-like
ST258/512 in Greece, Italy, and Spain,
bla
OXA-48
ST101 in Serbia and Romania,
bla
NDM
ST11 in Greece, and
bla
OXA-48-like
ST14 in Türkiye. Genomic surveillance across Europe thus provides crucial insights for local risk mapping and informs necessary adaptions for implementation of control strategies.
Klebsiella pneumoniae
is an opportunistic pathogen of increasing concern due to the spread of carbapenem resistance. In this study, the authors sequence carbapenem-resistant strains from a hospital surveillance network in southern Europe, describe evolution of high-risk clones, and identify locally important lineages.
Journal Article
Prevalence of Extended-Spectrum β-Lactamase-Producing Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae in Wastewater Effluent in Blantyre, Malawi
by
Mkwanda, Charity
,
Scudeller, Luigia
,
Masoambeta, Edward
in
Amoxicillin
,
Antibiotic resistance
,
Antibiotics
2025
Background/Objectives: Wastewater treatment plants (WWTPs) serve as a sink for both antimicrobial residues and bacteria carrying resistant genes, which are later disseminated into the environment, facilitating the spread of antimicrobial resistance. This study investigated the presence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (Ec), Klebsiella pneumoniae (Kp), and Enterobacter cloacae (Enc) in effluent from WWTP in Blantyre, Malawi, to generate evidence and provide baseline information for interventions. Methods: Selective chromogenic agar was used to identify ESBL-producing bacteria. Results: A total of 288 samples were collected between April 2023 and March 2024, and 97.6% (281/288) yielded one or more presumptive ESBL isolates. Bacterial growth was confirmed as 48.9% Ec (255/522), 33.0% Kp (172/522), and 10.0% Enc (52/522). Antibiotic susceptibility testing showed the highest resistance to ceftriaxone (Ec, 100.0%; Kp, 98.3%; Enc, 100.0%) and the lowest resistance to meropenem (Ec, 6.3%, Kp, 1.2%; Enc, 3.8%) among the antibiotics that were tested. Multiple antibiotic resistance phenotypes were observed in 73.1% of the isolates, with the most prevalent phenotype being amoxicillin + clavulanate/cotrimoxazole/doxycycline/ciprofloxacin/gentamicin/azithromycin/ceftriaxone (55, 15.7%). Conclusions: The study demonstrated ongoing environmental contamination with antibiotic-resistant bacteria from sewage effluent. Therefore, the functionality of WWTPs should be improved to minimize the release of these organisms into the environment.
Journal Article
Economic costing methodologies for drug-resistant bacterial infections in humans in low-and middle-income countries: a systematic review
by
Mkwanda, Charity
,
Chizani, Kenneth
,
Mwinjiwa, Edson
in
Antimicrobial agents
,
Antimicrobial resistance
,
Bacterial infections
2025
Background
This review examined methodologies used to cost the impact of antimicrobial resistance (AMR) infections in humans from household and health system perspectives. Although extensive research has been conducted on the clinical AMR burden in low- and middle-income countries (LMICs) in terms of prevalence and other drivers of antimicrobial resistance, there is increased misuse and overuse of antibiotics which increases the risk of AMR infections compared to high-income countries. Lack of comprehensive estimates on economic costs of AMR in LMICs due to lack of standard methodologies that incorporate time biases and inference for instance, may negatively affect accuracy and robustness of results needed for reliable and actionable policies.
Methods
We conducted a systematic review of studies searched in PubMed and other electronic databases. Only studies from LMICs were included. Data were extracted via a modified Covidence template and a Joanna Briggs Institute (JBI) assessment tool for economic evaluations to assess the quality of the papers.
Results
Using PRISMA, 2542 papers were screened at the title and abstract levels, of which 148 were retrieved for full-text review. Of these, 62 articles met the inclusion criteria. The articles had a quality assessment score averaging 85%, ranging from 63 to 100%. Most studies, 13, were from China (21%), followed by 8 from South Africa (13%). Tuberculosis (TB), general bacterial, and nosocomial infection costs are the most studied, accounting for 40%, 39%, and 6%, respectively with TB common in South Africa than the rest of the countries. The majority of the papers used a microcosting approach (71%), followed by gross costing (27%), while the remainder used both. Most studies analyzed costs descriptively (61%), followed by studies using regression-based techniques (17%) and propensity score matching (5%), among others.
Conclusion
Overall, the use of descriptive statistics without justification, limited consideration for potential data challenges, including confounders, and short-term horizons suggest that the full AMR cost burden in humans in LMICs has not been well accounted for. Given the limited data available for these studies, the use of a combination of methodologies may help triangulate more accurate and policy-relevant estimates. While the resources to conduct such cost studies are limited, the use of modeling costs via regression techniques while adjusting for cofounding could help maximize robustness and better estimate the vast and varied burden derived directly and indirectly from AMR.
Journal Article
Microbiological characterization of Streptococcus pneumoniae and non-typeable Haemophilus influenzae isolates as primary causes of acute otitis media in Bulgarian children before the introduction of conjugate vaccines
by
Setchanova, Lena P
,
Nashev, Dimitar
,
Kostyanev, Tomislav
in
Acute otitis media
,
Adolescent
,
Amino Acid Substitution
2013
Background
Pneumococcal and
Haemophilus influenzae
type b (Hib) vaccines were introduced in our national immunisation program in April 2010. The aims of this retrospective, laboratory-based study were to determine the serotypes and antibiotic resistance of
Streptococcus pneumoniae
and
H
.
influenzae
isolates from middle ear fluid (MEF) collected before the introduction of immunization.
Methods
S. pneumoniae
(n = 128) and
H. influenzae
(n = 40) strains isolated from MEF of children with AOM between 1994 and 2011 were studied. MICs were determined by a microdilution assay. Serotyping of
S. pneumoniae
was done by Quellung method and PCR capsular typing was used for
H. influenzae
. Macrolide resistance genes were detected by PCR for erythromycin resistant
S. pneumoniae
(ERSP). DNA sequencing of
fts
I gene was performed for ampicillin nonsusceptible
H. influenzae
.
Results
The most common serotypes found among children with pneumococcal AOM were 19 F (20.3%), 6B (15.6%), and 19A (10.9%). The potential coverage rates by the PCV7, PCV10 and PCV13 of children aged < 5 years were 63.6%, 66.4% and 85.5%, respectively. Reduced susceptibility to oral penicillin was seen in 68.1%; resistance to erythromycin was 46.9%. We found
erm
(B) gene in 56.7% of the ERSP,
mef
(E) gene in 25%; 15% harbored both genes
erm
(B) +
mef
(E) and 3.3% had mutations of L4 ribosomal protein. Of the 40
H. influenzae
isolates 97.5% were nontypeable. Nonsusceptibility to ampicillin occurred in 25%. Ampicillin resistance groups were: β-lactamase-positive ampicillin resistant (BLPAR) strains (10%), β-lactamase-negative ampicillin resistant (BLNAR) strains (12.5%) and β-lactamase-positive amoxicillin-clavulanate resistant (BLPACR) strains (2.5%). Among BLNAR and BLPACR most of the isolates (5/6) belonged to group II, defined by the Asn526Lys substitution.
Conclusions
The levels of antibiotic resistance among
S. pneumoniae
and
H. influenzae
causing severe AOM in children are high in our settings. The existence of multidrug-resistant
S. pneumoniae
serotype 19A is of particular concern. The rate of BLNAR and BLPACR strains among
H. influenzae
isolates was 15%.
Journal Article
Virulence factors and mechanisms of antibiotic resistance of haemophilus influenzae
by
Kostyanev, Tomislav S.
,
Sechanova, Lena P.
in
antibiotic resistance
,
Drug Resistance, Bacterial
,
Haemophilus infl uenzae
2012
Haemophilus influenzae is a small gram-negative coccobacillus known as one of the major causes of meningitis, otitis media, sinusitis and epiglottitis, especially in childhood, as well as infections of the lower respiratory tract, eye infections and bacteremia. It has several virulence factors that play a crucial role in patient infl ammatory response. Its capsule, the adhesion proteins, pili, the outer membrane proteins, the IgA1 protease and, last but not least, the lipooligosaccharide, increase the virulence of H. infl uenzae by participating actively in the host invasion the host by the microrganism. Some of these factors are used in vaccine preparations. In the post-vaccine era, an increase has been noticed in many European countries of invasive infections caused by non-encapsulated strains of H. influenzae which have a number of virulence factors, some of which are subject of serious research aiming at creating new vaccines. Numerous mechanisms of antibiotic resistance in H. infl uenzae are known which can compromise the empirical treatment of infections caused by this microorganism. The increasing incidence of resistance to aminopenicillins, induced not only by enzyme mechanisms but also by a change of their target is turning into a signifi cant problem. Resistance to other antibiotics such as macrolides, tetracyclines, chloramphenicol, trimethoprim/sulfamethoxazole, and fl uoroquinolones, commonly used to treat Haemophilus infections has also been described.
Journal Article
Transferable exclusivity voucher: a flawed incentive to stimulate antibiotic innovation
by
Årdal, Christine
,
McDonnell, Anthony
,
Magrini, Nicola
in
Anti-Bacterial Agents
,
Antibiotics
,
Bacteriology
2024
The cost to European countries is estimated at €350–840 million per voucher (the difference between the monopoly and generic or biosimilar prices).5,6 These estimates are likely to underestimate the true costs to payers because the data are from industry-sponsored reports in which the authors average annual sales of biopharmaceuticals in their final exclusivity year, including those with moderate sales.5 Yet the voucher would only be applied to the most profitable medicines, so averaging reduces the estimated cost of the voucher substantially. From a purely economic perspective, it is more cost-effective to invest in interventions that would reduce all multidrug-resistant pathogens rather than in multiple antibiotics impacting only a few pathogens or resistance patterns.3,13 As European countries struggle to make novel, effective, high-priced medicines accessible, the transferable exclusivity voucher will prolong inaccessibility and could disproportionately affect patients with rare diseases.14 Novel medicines that treat only 2–3% of patients are anticipated to constitute half of high-income country pharmaceutical expenditure by 2026.15 Additionally, a transferable exclusivity voucher could have detrimental effects on the development of biosimilars. [...]by putting forward the voucher the EC is undercutting the actions of its own Health Emergency Preparedness and Response Authority (HERA), which has commissioned further analyses of incentives for antibiotic access and innovation including a European-wide annual revenue guarantee.16–18 This incentive aims to simultaneously stimulate innovation and secure access to important antibiotics by paying guaranteed amounts for access to selected antibiotics, rather than consumption.
Journal Article
Assessment of three antibiotic combination regimens against Gram-negative bacteria causing neonatal sepsis in low- and middle-income countries
2024
Gram-negative bacteria (GNB) are a major cause of neonatal sepsis in low- and middle-income countries (LMICs). Although the World Health Organization (WHO) reports that over 80% of these sepsis deaths could be prevented through improved treatment, the efficacy of the currently recommended first- and second-line treatment regimens for this condition is increasingly affected by high rates of drug resistance. Here we assess three well known antibiotics, fosfomycin, flomoxef and amikacin, in combination as potential antibiotic treatment regimens by investigating the drug resistance and genetic profiles of commonly isolated GNB causing neonatal sepsis in LMICs. The five most prevalent bacterial isolates in the NeoOBS study (NCT03721302) are
Klebsiella pneumoniae
,
Acinetobacter baumannii
,
E. coli
,
Serratia marcescens
and
Enterobacter cloacae
complex. Among these isolates, high levels of ESBL and carbapenemase encoding genes are detected along with resistance to ampicillin, gentamicin and cefotaxime, the current WHO recommended empiric regimens. The three new combinations show excellent in vitro activity against ESBL-producing
K. pneumoniae
and
E. coli
isolates. Our data should further inform and support the clinical evaluation of these three antibiotic combinations for the treatment of neonatal sepsis in areas with high rates of multidrug-resistant Gram-negative bacteria.
High levels of extended spectrum beta-lactamase (ESBL) and carbapenemase encoding genes were detected in bacterial isolates causing neonatal sepsis in LMICs. Authors assess the in vitro activity of three antibiotics (fosfomycin, flomoxef and amikacin) in combination against ESBL-producing
Klebsiella pneumoniae
and
Escherichia coli
isolates.
Journal Article
Innovative Medicines Initiative and antibiotic resistance
by
O'Brien, Seamus
,
Goossens, Herman
,
Kostyanev, Tomislav
in
Antibiotic resistance
,
Antibiotics
,
Business models
2015
The Innovative Medicines Initiative is a PPP jointly developed by the European Federation of Pharmaceutical Industries and Associations (EFPIA) and the European Union (EU). Since its start in 2008, the Innovative Medicines Initiative has funded several large projects in various fields of medicine. Combatting Bacterial Resistance in Europe--Carbapenem Resistance (COMBACTE-CARE), Combatting Bacterial Resistance in Europe--Molecules Against Gram Negative Infections (COMBACTE-MAGNET), and Inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis (iABC).5 Two other projects of the programme, TRANSLOCATION (molecular basis of the bacterial cell wall permeability) and ENABLE (The European Gram-negative antibacterial engine), aim to boost the discovery of new molecules to treat Gram-negative infections.5 Another project in the ND4BB programme--Driving Re-InVEstment in R&D and responsible use of AntiBiotics (DRIVE-AB)--targets antibiotic resistance from an economic point of view, assessing current and developing new economic strategies.
Journal Article
Patterns of antibiotic use, pathogens, and prediction of mortality in hospitalized neonates and young infants with sepsis: A global neonatal sepsis observational cohort study (NeoOBS)
2023
Background There is limited data on antibiotic treatment in hospitalized neonates in low- and middle-income countries (LMICs). We aimed to describe patterns of antibiotic use, pathogens, and clinical outcomes, and to develop a severity score predicting mortality in neonatal sepsis to inform future clinical trial design. Methods and findings Hospitalized infants <60 days with clinical sepsis were enrolled during 2018 to 2020 by 19 sites in 11 countries (mainly Asia and Africa). Prospective daily observational data was collected on clinical signs, supportive care, antibiotic treatment, microbiology, and 28-day mortality. Two prediction models were developed for (1) 28-day mortality from baseline variables (baseline NeoSep Severity Score); and (2) daily risk of death on IV antibiotics from daily updated assessments (NeoSep Recovery Score). Multivariable Cox regression models included a randomly selected 85% of infants, with 15% for validation. A total of 3,204 infants were enrolled, with median birth weight of 2,500 g (IQR 1,400 to 3,000) and postnatal age of 5 days (IQR 1 to 15). 206 different empiric antibiotic combinations were started in 3,141 infants, which were structured into 5 groups based on the World Health Organization (WHO) AWaRe classification. Approximately 25.9% (n = 814) of infants started WHO first line regimens (Group 1—Access) and 13.8% (n = 432) started WHO second-line cephalosporins (cefotaxime/ceftriaxone) (Group 2—“Low” Watch). The largest group (34.0%, n = 1,068) started a regimen providing partial extended-spectrum beta-lactamase (ESBL)/pseudomonal coverage (piperacillin-tazobactam, ceftazidime, or fluoroquinolone-based) (Group 3—“Medium” Watch), 18.0% (n = 566) started a carbapenem (Group 4—“High” Watch), and 1.8% (n = 57) a Reserve antibiotic (Group 5, largely colistin-based), and 728/2,880 (25.3%) of initial regimens in Groups 1 to 4 were escalated, mainly to carbapenems, usually for clinical deterioration (n = 480; 65.9%). A total of 564/3,195 infants (17.7%) were blood culture pathogen positive, of whom 62.9% (n = 355) had a gram-negative organism, predominantly Klebsiella pneumoniae (n = 132) or Acinetobacter spp. (n = 72). Both were commonly resistant to WHO-recommended regimens and to carbapenems in 43 (32.6%) and 50 (71.4%) of cases, respectively. MRSA accounted for 33 (61.1%) of 54 Staphylococcus aureus isolates. Overall, 350/3,204 infants died (11.3%; 95% CI 10.2% to 12.5%), 17.7% if blood cultures were positive for pathogens (95% CI 14.7% to 21.1%, n = 99/564). A baseline NeoSep Severity Score had a C-index of 0.76 (0.69 to 0.82) in the validation sample, with mortality of 1.6% (3/189; 95% CI: 0.5% to 4.6%), 11.0% (27/245; 7.7% to 15.6%), and 27.3% (12/44; 16.3% to 41.8%) in low (score 0 to 4), medium (5 to 8), and high (9 to 16) risk groups, respectively, with similar performance across subgroups. A related NeoSep Recovery Score had an area under the receiver operating curve for predicting death the next day between 0.8 and 0.9 over the first week. There was significant variation in outcomes between sites and external validation would strengthen score applicability. Conclusion Antibiotic regimens used in neonatal sepsis commonly diverge from WHO guidelines, and trials of novel empiric regimens are urgently needed in the context of increasing antimicrobial resistance (AMR). The baseline NeoSep Severity Score identifies high mortality risk criteria for trial entry, while the NeoSep Recovery Score can help guide decisions on regimen change. NeoOBS data informed the NeoSep1 antibiotic trial (ISRCTN48721236), which aims to identify novel first- and second-line empiric antibiotic regimens for neonatal sepsis. Trial registration ClinicalTrials.gov, (NCT03721302). James Neal Russell and colleagues report a global neonatal sepsis observational cohort study (NeoOBS) exploring patterns of antibiotic use, pathogens and prediction of mortality in hospitalised neonates and young infants with sepsis. Author summary Why was this study done? Increasing trends in antimicrobial resistance (AMR) disproportionately affect neonates and young infants with sepsis in LMIC settings and undermine the effectiveness of WHO-recommended antibiotics. Despite this, longitudinal data on antibiotic management strategies and outcomes of hospitalized neonates and young infants with sepsis in low- and middle-income country (LMIC) settings are extremely limited, impeding the design of robust antibiotic trials. There is limited data to define risk stratification, inclusion, and escalation criteria in trials of sepsis in hospitalized neonates and young infants. What did the researchers do and find? In this large global, prospective, hospital-based observational study across 4 continents, including LMIC settings, there was a high mortality among infants with culture positive sepsis (almost 1 in 5), and a significant burden of antibiotic resistance. This study highlights wide variations in standard of care (SOC) for sepsis in neonates and young infants, with more than 200 different antibiotic combinations, significant divergence from WHO-recommended regimens, and frequent switching of antibiotics. A NeoSep Severity Score that defined patterns of mortality risk at baseline was developed from 4 non-modifiable and 6 modifiable factors that are feasible to measure across a range of LMIC hospital contexts. A NeoSep Recovery Score including the same modifiable factors (with the addition of cyanosis) predicted mortality on the following day during treatment. What do these findings mean? These data demonstrate that patterns of routine antibiotic use are now markedly divergent from global guidance. There is an urgent need for large pragmatic randomized controlled trials to address optimal empiric first- and second-line antibiotic treatment strategies in LMIC hospital settings with a significant AMR burden. The wide range of multiple antibiotic regimens routinely used as SOC suggests the need for novel trial designs. The NeoSep Severity Score and NeoSep Recovery Score informed inclusion and escalation criteria in the NeoSep1 antibiotic trial (ISRCTN48721236) that aims to identify novel first- and second-line empiric antibiotic regimens for neonatal sepsis.
Journal Article
A one health framework to estimate the cost of antimicrobial resistance
by
Årdal, Christine
,
Frost, Isabel
,
Scudeller, Luigia
in
Analysis
,
Animal human relations
,
Antibiotics
2020
Objectives/purpose
The costs attributable to antimicrobial resistance (AMR) remain theoretical and largely unspecified. Current figures fail to capture the full health and economic burden caused by AMR across human, animal, and environmental health; historically many studies have considered only direct costs associated with human infection from a hospital perspective, primarily from high-income countries. The Global Antimicrobial Resistance Platform for ONE-Burden Estimates (GAP-ON€) network has developed a framework to help guide AMR costing exercises in any part of the world as a first step towards more comprehensive analyses for comparing AMR interventions at the local level as well as more harmonized analyses for quantifying the full economic burden attributable to AMR at the global level.
Methods
GAP-ON€ (funded under the JPIAMR 8th call (Virtual Research Institute) is composed of 19 international networks and institutions active in the field of AMR. For this project, the Network operated by means of Delphi rounds, teleconferences and face-to-face meetings. The resulting costing framework takes a bottom-up approach to incorporate all relevant costs imposed by an AMR bacterial microbe in a patient, in an animal, or in the environment up through to the societal level.
Results
The framework itemizes the epidemiological data as well as the direct and indirect cost components needed to build a realistic cost picture for AMR. While the framework lists a large number of relevant pathogens for which this framework could be used to explore the costs, the framework is sufficiently generic to facilitate the costing of other resistant pathogens, including those of other aetiologies.
Conclusion
In order to conduct cost-effectiveness analyses to choose amongst different AMR-related interventions at local level, the costing of AMR should be done according to local epidemiological priorities and local health service norms. Yet the use of a common framework across settings allows for the results of such studies to contribute to cumulative estimates that can serve as the basis of broader policy decisions at the international level such as how to steer R&D funding and how to prioritize AMR amongst other issues. Indeed, it is only by building a realistic cost picture that we can make informed decisions on how best to tackle major health threats.
Journal Article