scholarly journals In vitro conjugation kinetics of ESBL-producing Escherichia coli donors and various Enterobacteriaceae recipients

2020 ◽  
Author(s):  
Eva-Maria Saliu ◽  
Jürgen Zentek ◽  
Wilfried Vahjen
Keyword(s):  
Serratia Marcescens ◽  
Proteus Mirabilis ◽  
Enterobacter Cloacae ◽  
Genetic Transfer ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Frequent Event ◽  
Wide Range ◽  
The Given

Abstract Background: Extended spectrum beta-lactamase (ESBL)-producing enterobacteria pose a major hazard to public health. Due to the possibility of genetic transfer, ESBL genes might spread to pathogenic enterobacterial strains. Thus, information on possible genetic transfer between enterobacteria is of high interest. It was therefore the aim of this in vitro study to screen the capacity of a wide range of Enterobacteriaceae for time dependent differences in conjugation with five ESBL-producing Escherichia (E.) coli strains. Results: Conjugation frequencies for five potential E. coli donor strains, producing the enzymes CTX-M-1, CTX-M-15, SHV-12, TEM-1, TEM-52 and CMY-2, and six potential recipient strains (E. coli, Serratia marcescens subsp. marcescens, Enterobacter cloacae, Salmonella Typhimurium and Proteus mirabilis) were obtained. Hence, different combinations of donor and recipient strains were co-incubated for between 0 and 22 hours and spread on selective agar. Conjugation frequencies were calculated as transconjugants per donor. Some of the donor and recipient strain combinations did not show plasmid transfer within 22 hours. Hence, the recipient Proteus mirabilis did not accept plasmids from any of the given donors and E. coli ESBL10716 was not able to transfer its plasmid to any recipient. Enterobacter cloacae only accepted the plasmids from the donors E. coli ESBL10708 and E. coli ESBL10716 while E. coli ESBL10708 did not transfer its plasmid to Serratia marcescens subsp. marcescens. E. coli IMT11716 on the other hand did not perform conjugation with the donor E. coli ESBL10689. The remaining mating pairs differed in conjugation frequency, ranging from log -5 to -8.5 transconjugants/donor. The earliest conjugation events were detected after 4 hours. However, some mating pairs turned positive only after 22 hours co-incubation.Conclusion: The results of this study suggest that conjugation is a frequent event in the spread of ESBL genes among commensal and pathogen bacteria. This should be considered when addressing antibiotic resistance issues.

scholarly journals PERFIL DE SENSIBILIDADE A ANTIMICROBIANOS POR COMPONENTES DA MICROBIOTA BACTERIANA ORAL E RETAL DE PRIMATAS NÃO HUMANOS

2019 ◽  
Vol 20 ◽  
Author(s):  
Marcone Helmer Silva ◽  
Hilma Lúcia Tavares Dias ◽  
Ednaldo da Silva Filho ◽  
Sarah Raphaela Rocha de Azevedo Scalercio ◽  
Wellington Bandeira da Silva ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Serratia Marcescens ◽  
Proteus Mirabilis ◽  
Enterobacter Cloacae ◽  
Callithrix Jacchus ◽  
E Coli ◽  
Staphylococcus Xylosus

Resumo Os objetivos desta pesquisa foram identificar bactérias isoladas da cavidade oral e da ampola retal de Saimiri collinsi e Callithrix jacchus e determinar a sensibilidade a 16 antimicrobianos. Trinta indivíduos de cada espécie foram analisados e foram isoladas 136 bactérias em C. jacchus e 84 em S. collinsi. As bactérias isoladas em maior número em S. collinsi foram Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Raoutella ornithinolytica, Staphylococcus xylosus e Proteus mirabilis. As bactérias isoladas em C. jacchus foram K. pneumoniae, E. cloacae, E. coli, Serratia marcescens e S. xylosus na cavidade oral e ampola retal. O teste de sensibilidade mostrou que, dentre as cepas isoladas, os maiores percentuais de resistência foram observados para ampicilina, amoxicilina, cefalotina e nitrofurantoína. Na cavidade oral de ambas as espécies as cepas foram sensíveis à ceftazidima, ceftriaxona, meropenem, amicacina, levofloxacina e a sulfametoxazol/trimetoprim. Na ampola retal, as isoladas foram sensíveis à cefoxitina, ceftazidima, ceftriaxona, ertapenem, meropenem, amicacina e levofloxacina. Conclui-se que as espécies de S. collinsi e C. jacchus apresentam sua microbiota oral e retal composta por várias espécies bacterianas e que a resistência pode ser um problema no criatório, uma vez que as cepas mostraram percentuais elevados de resistência a diferentes antimicrobianos.

scholarly journals A Toxic Environment: a Growing Understanding of How Microbial Communities Affect Escherichia coli O157:H7 Shiga Toxin Expression

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Erin M. Nawrocki ◽  
Hillary M. Mosso ◽  
Edward G. Dudley
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Microbial Interactions ◽  
Severe Illness ◽  
Content Type ◽  
E Coli ◽  
Wide Range ◽  
Lambdoid Prophage

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo. Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.

scholarly journals Volatile Oils ofNepeta tenuifolia(Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  
Keyword(s):  
Essential Oils ◽  
In Vitro Study ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Gram Negative ◽  
E Coli ◽  
Wide Range ◽  
Main Component ◽  
Reference Strains

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.

scholarly journals In Vitro and In Vivo Antibacterial Activities of SM-216601, a New Broad-Spectrum Parenteral Carbapenem

2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Activities ◽  
Multiresistant Pathogens ◽  
E Coli ◽  
Wide Range ◽  
Agar Dilution ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.

scholarly journals ДОКЛІНІЧНЕ ДОСЛІДЖЕННЯ НАНОЧАСТИНОК КУПРУМУ

2020 ◽  
pp. 99-106
Author(s):  
Y. S. Stravskyy ◽  
L. Ya. Fedoniuk ◽  
O. M. Yarema ◽  
L. S. Reznichenko
Keyword(s):  
Proteus Mirabilis ◽  
Enterobacter Aerogenes ◽  
Paecilomyces Lilacinus ◽  
E Coli ◽  
Penicillium Spp

Вступ. Доклінічне вивчення лікарських препаратів – невід’ємна частина процесу створення лікарського засобу. Встановлені, за результатами доклінічного вивчення, характеристики специфічної фармакологічної активності та нешкідливості під час застосування і щодо його ймовірних віддалених наслідків є принциповими факторами, які визначають можливість промислового випуску лікарського засобу та доцільність його медичного використання. Мета дослідження – вивчити біобезпечність, гостру токсичність, протимікробну та фунгіцидну дії наночастинок Купруму. Методи дослідження. Біобезпечність синтезованої субстанції наночастинок у тестах in vitro визначали з використанням показників цитотоксичності, мутагенності, молекулярно-генетичного (показник генотоксичності), фізіологічного (стан мікрофлори шлунково-кишкового тракту людини) та біохімічних (ATP-aзна і лактатдегідрогеназна активність) маркерів. Протимікробні та фунгіцидні властивості препарату було вивчено на клінічних ізолятах збудників інфекційно-запальних процесів: бактеріях S. aureus, E. coli, Proteus mirabilis, K. pneumoniae, Enterobacter aerogenes, P. aeruginosa, грибах роду Candida – C. albicans, Candida non-albicans та інших мікроміцетах – Penicillium spp., Paecilomyces lilacinus, A. niger і A. flavus. Результати й обговорення. Взаємодія наночастинок Купруму з тестовими еукаріотичними клітинами не призводила до появи первинних ДНК-ушкоджень порівняно з впливом N-нітрозометилсечовини, яка є відомим генотоксикантом. У зразках тестових еукаріотичних клітин лінії СНО-К1, оброблених наночастинками Купруму в широкому концентраційному діапазоні, не було зафіксовано цитотоксичного впливу досліджуваного наноматеріалу. Експериментальна субстанція наночастинок Купруму (CuNP) володіє вираженою протимікробною та фунгіцидною активністю відносно всіх досліджуваних патогенних тест-культур: як у вихідній концентрації (32,0 мг/мл у перерахунку на метал), так і при її десятикратному розведенні (3,2 мг/мл у перерахунку на метал). Повне інгібування росту патогенних тест-штамів спостерігали при використанні кінцевих засівних доз мікроорганізмів на чашках від 103 до 105 КУО/см3. Досліджувана субстанція наночастинок Купруму також проявляла протимікробну та фунгіцидну дії щодо клінічних ізолятів збудників інфекційно-запальних процесів різної локалізації, а саме бактерій і грибів. Висновок. Результати оцінювання гострої токсичності субстанції наночастинок Купруму після одноразового внутрішньовенного введення білим мишам залежно від рівня дози протягом 14 діб спостереження дозволяють віднести її до IV класу токсичності (малотоксичні речовини).

scholarly journals Chromosomally Encoded AmpC-Type β-Lactamase in a Clinical Isolate of Proteus mirabilis

1998 ◽  
Vol 42 (5) ◽  
pp. 1110-1114 ◽  
Author(s):  
L. Bret ◽  
C. Chanal-Claris ◽  
D. Sirot ◽  
E. B. Chaibi ◽  
R. Labia ◽  
...  
Keyword(s):  
Proteus Mirabilis ◽  
Point Mutations ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Clinical Strain ◽  
Citrobacter Freundii ◽  
Specific Primers ◽  
E Coli ◽  
Dna Fragment ◽  
Urine Specimens

ABSTRACT A clinical strain of Proteus mirabilis (CF09) isolated from urine specimens of a patient displayed resistance to amoxicillin (MIC >4,096 μg/ml), ticarcillin (4,096 μg/ml), cefoxitin (64 μg/ml), cefotaxime (256 μg/ml), and ceftazidime (128 μg/ml) and required an elevated MIC of aztreonam (4 μg/ml). Clavulanic acid did not act synergistically with cephalosporins. Two β-lactamases with apparent pIs of 5.6 and 9.0 were identified by isoelectric focusing on a gel. Substrate and inhibition profiles were characteristic of an AmpC-type β-lactamase with a pI of 9.0. Amplification by PCR with primers for ampC genes (Escherichia coli,Enterobacter cloacae, and Citrobacter freundii) of a 756-bp DNA fragment from strain CF09 was obtained only withC. freundii-specific primers. Hybridization results showed that the ampC gene is only chromosomally located while theTEM gene is plasmid located. After cloning of the gene, analysis of the complete nucleotide sequence (1,146 bp) showed that this ampC gene is close tobla CMY-2, from which it differs by three point mutations leading to amino acid substitutions Glu → Gly at position 22, Trp → Arg at position 201, and Ser → Asn at position 343. AmpC β-lactamases derived from that of C. freundii (LAT-1, LAT-2, BIL-1, and CMY-2) have been found in Klebsiella pneumoniae, E. coli, and Enterobacter aerogenes and have been reported to be plasmid borne. This is the first example of a chromosomally encoded AmpC-type β-lactamase observed in P. mirabilis. We suggest that it be designated CMY-3.

scholarly journals 1592. In Vitro Activity of Ceftolozane/Tazobactam (C/T) Against Enterobacteriaceae and Pseudomonas aeruginosa Circulating in Chile

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S581-S581
Author(s):  
Lina M Rivas ◽  
Jose R W Martínez ◽  
Maria Spencer ◽  
Lorena Porte ◽  
Francisco Silva ◽  
...  
Keyword(s):  
Tertiary Care ◽  
Multidrug Resistant ◽  
Global Public Health ◽  
Health Crisis ◽  
Clinical Strains ◽  
E Coli ◽  
Highly Active ◽  
Complex Figure ◽  
Wide Range

Abstract Background The widespread dissemination of carbapenem-resistant (CR) P. aeruginosa and Enterobacteriaceae has created a major global public health crisis. C/T is a recently approved therapeutic which consists of the combination of a novel cephalosporin (ceftolozane) and tazobactam (a β-lactamase inhibitor). C/T has shown good activity against a wide range of multidrug-resistant (MDR) Gram negatives, being particularly interesting as an alternative for MDR P. aeruginosa. We aimed to determine the activity of C/T against clinical strains of Enterobacteriaceae and P. aeruginosa recovered in 4 large clinical centers from Chile. Methods We analyzed 434 isolates of Enterobacteriaceae (347 E. coli, 66 K. pneumoniae, 21 Enterobacter cloacae complex) and 57 P. aeruginosa collected during 2017 from 4 tertiary care institutions in Santiago, Chile. Identification was performed as per each local clinical microbiology lab. Susceptibility testing was performed by broth microdilution using customized Sensititre plates (Trek). Carba-NP was performed to screen for carbapenemase production. Susceptibilities were analyzed as per 2019 CLSI breakpoints. Results The MIC50/90 for C/T against Enterobacteriaceae and P. aeruginosa were 1/4 μg/mL and 2/16 μg/mL, respectively. In Enterobacteriaceae, susceptibility to C/T reached 92% in E. coli (Figure 1A), 91% in E. cloacae complex (Figure 1B) and 70% in K. pneumoniae (Figure 1C). Remarkably, C/T remained active against 58% (33/57) of CR Enterobacteriaceae (Figure 2A). Among Carba-NP-negative CR isolates (46%, 26/57), susceptibility to C/T was 54% (Figure 3 A–C). In P. aeruginosa, the overall susceptibility to C/T was 81% (Figure 1D), maintaining activity against 69% (25/36) of CR strains (Figure 2B). Importantly, susceptibility to C/T in CR P. aeruginosa isolates with a negative Carba-NP (67%, 24/36) was 83% (20/24) (Figure 3D). Conclusion In this multicenter study, we observed that C/T was highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa. Of note, C/T remained active against a large proportion of CR clinical strains. Moreover, the activity of C/T was particularly high against CR P. aeruginosa isolates with a negative Carba-NP. Disclosures All authors: No reported disclosures.

scholarly journals Characteristics ofEscherichia coliIsolated from Bovine Mastitis Exposed to Subminimum Inhibitory Concentrations of Cefalotin or Ceftazidime

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Gang Liu ◽  
Laidi Ding ◽  
Bo Han ◽  
Sofie Piepers ◽  
S. Ali Naqvi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Morphological Changes ◽  
Bovine Mastitis ◽  
Clinical Mastitis ◽  
Powdered Infant Formula ◽  
Formula Milk ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli

Escherichia coliis a major udder pathogen causing clinical mastitis in dairy cattle and its heat stable endotoxin in powdered infant formula milk is a potential risk factor in neonatal infections. Cephalosporins are frequently used for treatment of mastitis caused by mastitis; however, use of these antimicrobials may induce antimicrobial resistance inE. coli. The objective of this study was to explore thein vitroeffect of subminimum inhibitory concentrations (sub-MIC) of cefalotin (CF) and ceftazidime (CAZ) on the morphology, antimicrobial resistance, and endotoxin releasing characteristics of 3E. coliisolates recovered from bovine clinical mastitis. The parentE. coliisolates, which were susceptible to CF and CAZ, were exposed to CF or CAZ separately at sub-MIC levels to produce 9 generations of induced isolates. Colonies of the CAZ-induced isolates from all 3 parentE. coliwere smaller on blood agar and the bacteria became filamentous, whereas the CF-induced isolates did not demonstrate prominent morphological changes. After induction by CF or CAZ, many induced isolates showed resistance to cefoxitin, CAZ, CF, kanamycin, ampicillin, and amoxicillin/clavulanic acid while their parent isolates were susceptible to these antimicrobials. Notably, 5 CAZ-induced isolates from the same parent isolate were found to produce extended-spectrum beta-lactamase (ESBL) though none of the tested ESBL related genes could be detected. All CAZ-induced isolates released more endotoxin with a higher release rate, whereas endotoxin release of CF-inducedE. coliisolates was not different from parent isolates. The exposure of cephalosporins at sub-MIC levels induced resistantEscherichia coli.We inferred that cephalosporins, especially CAZ, should be used prudently for treatment of clinicalE. colimastitis.

Phänotypische Antibiotikaresistenzen von Bakterienisolaten aus Zier-, Zoo- und falknerisch gehaltenen Greifvögeln

2020 ◽  
Vol 48 (04) ◽  
pp. 260-269
Author(s):  
Leonie Steger ◽  
Monika Rinder ◽  
Rüdiger Korbel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Enterobacter Cloacae ◽  
Coli Isolate ◽  
Aureus Isolate ◽  
E Coli ◽  
Klinische Relevanz

Zusammenfassung Gegenstand und Ziel Die Prävalenz von antibiotikaresistenten Bakterien bei Zier-, Zoo- und falknerisch gehaltenen Greifvögeln ist noch weitgehend unbekannt. Daher sollten retrospektiv Antibiogramme schnellwachsender aerober Bakterienarten ausgewertet werden. Material und Methoden Im Auswertungszeitraum von 2007 bis 2016 standen 1036 Antibiogramme zur Verfügung. Die Bakterienisolate stammten vorzugsweise aus Süddeutschland und von 811 Vögeln aus 20 zoologischen Ordnungen (am häufigsten Papageienvögel [61,8 %] und Sperlingsvögel [14,5 %]) sowie aus Proben von klinischen Patienten und Sektionsmaterial. Die phänotypische In-vitro-Empfindlichkeit wurde mittels Plattendiffusionstest ermittelt. Ergebnisse Die meisten Antibiogramme lagen für E. coli (n = 386 Isolate) vor, gefolgt von Staphylococcus (S.). aureus (n = 150), Enterobacter cloacae (n = 122), Klebsiella pneumoniae (n = 86) und Pseudomonas aeruginosa (n = 64). Resistenzen gegen mindestens einen antibiotischen Wirkstoff zeigten 53,1 % der E. coli-Isolate, dabei am häufigsten gegen Doxycyclin (50,3 %) und Ampicillin (46,1 %). Bei 78,0 % der S. aureus-Isolate und bei 95,9 % der Enterococcus faecalis-Isolate wurden Resistenzen gegenüber mindestens einem Wirkstoff nachgewiesen. Multiresistenzen (Resistenz gegenüber ≥ 3 Antibiotikagruppen) traten bei 37,3 % der Isolate von S. aureus auf. Bei Isolaten von Zier- und Greifvögeln wurden höhere Resistenzraten festgestellt als bei Isolaten von Zoovögeln und bei Papageienvögeln höhere Resistenzraten als bei Sperlingsvögeln. Im Untersuchungszeitraum zeigte sich bei E. coli ein tendenzieller Anstieg der Resistenzrate für Fluorchinolone (Minimum von 0 % im Jahr 2013 und Maximum von 27,3 % im Jahr 2015) und bei S. aureus eine tendenzielle Abnahme der Resistenzraten für Tetrazykline (Maximum von 39,4 % im Jahr 2007 und Minimum von 0 % in den Jahren 2014 und 2015). Schlussfolgerung und klinische Relevanz Die Resistenzsituation von Bakterien aus Zier-, Zoo- und falknerisch gehaltenen Greifvögeln ist als problematisch zu bewerten und verdeutlicht die Wichtigkeit der Empfindlichkeitsprüfung für eine gewissenhafte Therapie. Im Fall einer Infektion mit S. aureus bei Zier-, Zoo- oder falknerisch gehaltenen Greifvögeln kann es zu einem Therapienotstand kommen.

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