resistance patterns
Recently Published Documents


TOTAL DOCUMENTS

2173
(FIVE YEARS 691)

H-INDEX

65
(FIVE YEARS 8)

2022 ◽  
Author(s):  
Gabriel Trueba ◽  
Diana Calderon ◽  
Paul A Cardenas ◽  
Maria Belen Prado ◽  
Jay Graham

The gastrointestinal tract constitutes a complex and diverse ecosystem. Escherichia coli is one of the most frequently studied and characterized species in the gut ecosystem, nevertheless, there has been little research to determine their diversity and population dynamics in the intestines of children over time. In this prospective study, a fresh fecal sample was obtained from children longitudinally over one year (30 fecal samples at sampling period 1 and 22 fecal samples at sampling periods 2 and 3). From each stool sample, five E. coli colonies were randomly selected (n = 405 E. coli isolates total) in order to characterize the genotype and phenotypic antimicrobial resistance patterns. We found that all numerically dominant E. coli lineages in children's intestines were transient colonizers, and antimicrobial resistance phenotypes of these strains varied significantly over time without any apparent selective force. Whole-genome sequencing of 3 isolates belonging to ST131 found in one child during the sampling period I and II indicated that isolates were three different ST 131 clones that carried extended-spectrum β-lactamase (ESBL) genes.


2022 ◽  
Vol 10 (1) ◽  
pp. 125
Author(s):  
Alexandra Wolff ◽  
Arne C. Rodloff ◽  
Paul Vielkind ◽  
Toralf Borgmann ◽  
Catalina-Suzana Stingu

Actinomyces species play an important role in the pathogenesis of oral diseases and infections. Susceptibility testing is not always routinely performed, and one may oversee a shift in resistance patterns. The aim of the study was to analyze the antimicrobial susceptibility of 100 well-identified clinical oral isolates of Actinomyces spp. against eight selected antimicrobial agents using the agar dilution (AD) and E-Test (ET) methods. We observed no to low resistance against penicillin, ampicillin-sulbactam, meropenem, clindamycin, linezolid and tigecycline (0–2% ET, 0% AD) but high levels of resistance to moxifloxacin (93% ET, 87% AD) and daptomycin (83% ET, 95% AD). The essential agreement of the two methods was very good for benzylpenicillin (EA 95%) and meropenem (EA 92%). The ET method was reliable for correctly categorizing susceptibility, in comparison with the reference method agar dilution, except for daptomycin (categorical agreement 87%). Penicillin is still the first-choice antibiotic for therapy of diseases caused by Actinomyces spp.


Animals ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Camilla Smoglica ◽  
Alberto Vergara ◽  
Simone Angelucci ◽  
Anna Rita Festino ◽  
Antonio Antonucci ◽  
...  

The aim of this study was to determine and characterize potential resistance mechanisms against selected Critically Important Antibiotics in Escherichia coli isolates collected from wild and domestic ruminants living in the Maiella National Park, in Central Italy. A total of 38 isolates were obtained from red deer, Apennine chamois, cattle, sheep, and goats grazing in lands with different levels of anthropic pressure. Antimicrobial susceptibility was determined by Minimal Inhibitory Concentration testing, showing phenotypic resistance to colistin, meropenem, or ceftazidime in 9 isolates along with one bacterial strain being resistant to three of the tested antibiotics. In addition, the biomolecular assays allowed the amplification of the genes conferring the colistin (mcr-4), the carbapenems (OXA-48), penicillins and cephalosporins (TEM, SHV, CMY-1, CMY-2) resistance. In order to describe the potential pathogenicity of isolates under study, virulence genes related to Shiga toxin-producing (STEC) and enteropathogenic (EPEC) pathovars were identified. This study is the first report of mcr-4 and OXA-48 genes in resistant E. coli harboring virulence genes in Italian wildlife, with special regard to Apennine chamois and red deer species. The multidisciplinary approach used in this study can improve the early detection of emerging antibiotic resistance determinants in human-animal-environment interfaces by means of wildlife monitoring.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Julia Notter ◽  
Salome N. Seiffert ◽  
Maria Zimmermann-Kogadeeva ◽  
Anja Bösch ◽  
Robert Wenger ◽  
...  

Abstract Background Data on antimicrobial resistance mechanisms are scanty for Cedecea spp., with very variable antibiotic resistance patterns documented. Here we report the first in vivo resistance evolution of a C. davisae clinical isolate in a patient with a complex hand trauma and provide insight in the resistance mechanism, leading to therapeutic implications for this pathogen. Case presentation Cedecea davisae was isolated from a patient with hand trauma during a first surgical debridement. Six days after primary surgical treatment and under antimicrobial treatment with amoxicillin-clavulanic acid and later cefepime, follow up cultures yielded C. davisae which demonstrated a resistance development. The susceptible parental isolate and its resistant derivative were characterized by whole genome sequencing, ampC, ompC and ompF by RT- PCR. The resistant derivative demonstrated an A224G SNP in ampD, the transcriptional regulator of ampC, leading to a His75Arg change in the corresponding AmpD protein. AmpC transcription of the resistant derivative was 362-times higher than the susceptible isolate. Transcription levels of ompF and ompC were 8.5-fold and 1.3-fold lower, respectively, in the resistant derivative. Downregulation of OmpF putatively resulted from a mutation in the presumed promoter region upstream of the dusB-Fis operon, a proposed regulator for ompF. Conclusions This case demonstrates the in vivo resistance development of C. davisae within 7 days similar to that of the members of the Enterobacter cloacae complex. Our findings add valuable information for future therapeutic management of these opportunistic pathogens as they warrant the same empirical treatment as AmpC producers.


Animals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 117
Author(s):  
Cecilia Kellerman ◽  
Pongpreecha Malaluang ◽  
Ingrid Hansson ◽  
Lena Eliasson Selling ◽  
Jane M. Morrell

Extenders for boar semen contain antibiotics, which may induce antimicrobial resistance (AMR) in inseminated females. The objective was to investigate AMR of bacteria isolated from the cervix of sows and gilts in standing heat, representing females previously exposed to antibiotics in the semen extender and non-exposed females, respectively. Cervical swabs were taken from 30 multiparous sows and 30 gilts prior to their first insemination. After culturing on agar plates, bacterial isolates were identified by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry and antimicrobial minimum inhibitory concentrations (MIC) were determined. Differences in antibiotic resistance between sows and gilts were analyzed by Chi-squared or Fisher’s exact test. Bacteria isolated were mostly Staphylococcus spp., Streptococcus spp. and Corynebacterium spp. Higher MICs were observed for isolates from sows than from gilts. Most (>80%) Corynebacterium spp. were resistant to clindamycin; small numbers (<20%) were resistant to gentamicin, penicillin, vancomycin, ciprofloxacin and rifampicin, with no differences between gilts and sows. Corynebacterium from gilts were more often resistant to tetracycline than those from sows (25% vs. 4.17%; p = 0.04). In conclusion, bacteria from the porcine cervix showed low resistance to most antibiotics except for clindamycin, but antibacterial resistance may increase with increasing parity.


Cureus ◽  
2021 ◽  
Author(s):  
Omaima A Shaaban ◽  
Nermin A Mahmoud ◽  
Anas A Zeidan ◽  
Nitya Kumar ◽  
Alan C Finan

2021 ◽  
pp. 3216-3223
Author(s):  
Thuan K. Nguyen ◽  
Lam T. Nguyen ◽  
Trang T. H. Chau ◽  
Tam T. Nguyen ◽  
Bich N. Tran ◽  
...  

Background and Aim: Salmonella is one of the leading causes of zoonotic and foodborne infectious outbreaks in humans and poultry and its associated environment is a potential reservoir of Salmonella. In recent years, the antibiotic resistance of bacteria, including Salmonella, has been increasing. This study aimed to investigate the prevalence and antibiotic resistance of Salmonella isolated from poultry, its environment, and the pest animals found at poultry farms and households of the Mekong Delta, Vietnam. Materials and Methods: A total of 3,055 samples were collected from the broiler farms and households of the Mekong Delta from 2017 to 2020. Salmonella was isolated using conventional methods (culturing on selective agar – BPLS and biochemical test) and the isolates were examined for antibiotic resistance against 14 antibiotics using the disk diffusion method. Results: Salmonella was isolated from 181 samples (5.92%), which included chicken feces (7.67%), pest animals (5.98%), and environmental samples (4.33%). The environmental samples comprised bedding (5.88%), feed (5.48%), and drinking water (0.70%). The prevalence of Salmonella was the highest in rats (15.63%) and geckos (12.25%) followed by ants (2.83%) and cockroaches (2.44%); however, Salmonella was not isolated from any fly species. Most of the isolates exhibited resistance to 1-9 antibiotics. The isolates were relatively resistant to chloramphenicol (62.98%), tetracycline (55.80%), ampicillin (54.14%), and sulfamethoxazole/trimethoprim (53.04%). Sixty-two multiple resistance patterns were found in the isolates, with ampicillin-cefuroxime-chloramphenicol-tetracycline- sulfamethoxazole/trimethoprim being the most frequent (7.18%). Conclusion: The chickens, husbandry environment, and pest animals at poultry farms and households were found to be important Salmonella sources in the Mekong Delta. Salmonella isolates from these sources also exhibited a wide-ranging resistance to antibiotics as well as several resistance patterns. Hence, biosecurity should be addressed in poultry farms and households to prevent cross-contamination and reduce the spread of Salmonella infections.


2021 ◽  
Author(s):  
Chikondi Isabel Joana Chapuma ◽  
Charlotte Van der veer ◽  
Edward J M Monk ◽  
Apatsa Selemani ◽  
David Kulapani ◽  
...  

Abstract Background: Over two-thirds of global maternal deaths occur in Sub-Saharan Africa (SSA), with more than 200,000 deaths per year. Maternal sepsis causes 10% of these deaths, twice the proportion observed in high-income countries. In SSA, limited access to diagnostic microbiology facilities poses difficulties in promptly identifying and managing maternal infection and sepsis. This protocol describes a systematic review and meta-analysis that aims to summarize available data on the main bacterial agents causing maternal infections and their antibiotic susceptibility in SSA. Methods: Three electronic databases will be searched: MEDLINE, Embase and African Journals Online. Our search strategy will combine terms relating to laboratory-confirmed bacterial infection, pregnancy, postnatal period and SSA. We will include observational studies describing maternal bacterial infection's aetiology and antimicrobial resistance patterns in SSA. Two authors will perform study selection, data extraction and quality assessment. A third author will be consulted to resolve disagreements if they arise.We will summarize the proportion (and 95% confidence intervals) of samples testing positive for the most common bacteria and, depending on the data's availability and heterogeneity, examine results by country and/or region. If possible, we will describe trends over time and differentiate aetiological organisms and resistance/sensitivities by maternal infection sources. We will also undertake subgroup analyses based on HIV status, the invasive and non-invasive status of the infection, SSA sub-regions and mortality if there is adequate information to make such subgroup analysis feasible. Discussion: Data on the microbiologic outcomes for maternal infections in SSA are likely fragmented and not fully representative due to the limited availability of microbiology diagnostics and geographical differences in clinical and laboratory practices. If this is the case, policies and programme strategies to guide treatment and identify antimicrobial resistance threats in SSA settings will be challenging to target. Our systematic review aims to provide a comprehensive summary of the available data, describe the main organisms causing maternal infection and their sensitivities, and identify areas that require further research. Prospero ID: CRD42021238515


2021 ◽  
Vol 11 (4) ◽  
pp. 642-657
Author(s):  
Shimaa Tawfeeq Omara ◽  
Ashraf Samir Hakim ◽  
Magdy Ali Bakry

Detailed information on the resistance patterns of Staphylococcus aureus (S. aureus) in milk and cheese is strongly required to facilitate risk assessment analysis in case of food poisoning context and to improve therapeutic approaches used in dairy farms. The present study aimed to perform phenotypic and genotypic antimicrobial characterizations of methicillin, vancomycin, and erythromycin-resistant S. aureus isolated from milk and dairy products through screening mecA, vanA, and ermC using molecular PCR amplification technology. Moreover, the association between each genotypic and its related antibiotic resistance phenotypic features within the isolated S. aureus strains were analyzed. Moreover, the current study aimed to study MRSA's ability to form biofilms. Out of 226 milk and dairy product samples collected from different retailers in Giza Governorate, 69.5% of the samples were positive for the presence of S. aureus. The isolation rate of S. aureus strains from cattle milk, sheep milk, white cheese, flamenco, and mesh samples were 79.7%, 76.5%, 56.0%, 40.0%, and 94.7%, respectively. Multidrug-resistant S. aureus (MDR) was detected in 51% of all isolated S. aureus strains. All tested S. aureus strains were sensitive to trimethoprim-sulfamethoxazole, linezolid, ciprofloxacin, and gentamycin. However, their resistance rates against penicillin, oxacillin, vancomycin, erythromycin, tetracycline, clindamycin and chloramphenicol were 62.4%, 65.0%, 44.6%, 45.9%, 21.0%, 14.0%, and 2.5%, respectively. Of the isolated S. aureus strains, 72.6%, 40.1%, and 48.4% were carriers for mecA, vanA, and ermC genes and the amplified products were at 310, 1030, and 295 bp, respectively. Methicillin-resistant S. aureus isolates were detected in 47.1% of all isolated S. aureus strains. The results indicated that 35.0% of the tested S. aureus strains were genotypic vanA gene carriers and phenotypic resistant to vancomycin representing vancomycin-resistant S. aureus strains. Moreover, 42.7% of all isolated S. aureus strains were carriers for ermC gene and were phenotypic resistant to erythromycin representing erythromycin-resistant S. aureus. The presence of mecA, vanA, and ermC genes in S. aureus was statistically associated with their related phenotypic resistance patterns against both penicillin and oxacillin, vancomycin, and erythromycin, respectively. Moreover, along with an increase in the frequency of mecA, vanA, and ermC genes, their phenotypic antibiotic resistance patterns sharply increased with an odd ratio >1. Of MRSA isolates, 6.8% indicated weak biofilm-formation ability, while 93.2% exhibit no biofilm-forming ability.


Sign in / Sign up

Export Citation Format

Share Document