Effect of Dimethyl Sulphoxide on the Expression of Nitrogen Fixation in Bacteria

Since the original construction of diazotrophic Escherichia coli by conjugal transfer of nif genes from Klebsiella pneumoniae in 1972, the manipulation of nif genes into alien prokaryotic backgrounds has become routine: much of the basic genetics of the K. pneumoniae nif cluster was elucidated in an E. coli background. Gene transfers to new species and genera can give new information regarding the stability of nif genes and, particularly, conditions for their expression; recipients in which nif is partly expressed, or not expressed at all, are especially useful. Appropriate examples are discussed. New diazotrophic prokaryotes show little promise for practical exploitation but their construction should give forewarning of problems to be expected in the construction of diazotrophic eukaryotes, as well as hints concerning the ecology and evolution of diazotrophy.

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Pathways of Energy Metabolism Required for Phenotypic Expression of Nif+Kp Genes in Escherichia Coli

Australian Journal of Biological Sciences ◽

10.1071/bi9790637 ◽

1979 ◽

Vol 32 (6) ◽

pp. 637 ◽

Cited By ~ 3

Author(s):

Mary L Skotnicki ◽

Barry G Rolfe

Keyword(s):

Escherichia Coli ◽

Nitrogen Fixation ◽

Energy Metabolism ◽

Electron Transport ◽

Nitrogenase Activity ◽

Phenotypic Expression ◽

E Coli ◽

Substrate Level Phosphorylation ◽

Fumarate Reduction ◽

Substrate Level

In E. coli K12 (F'nif+ KP) hybrids, electron-transport-dependent phosphorylation is not necessary for anaerobic nitrogen fixation, and substrate level phosphorylation can provide sufficient ATP from glucose for nitrogenase activity, The fumarate-reduction system, however, is essential in these hybrids for the transfer of electrons to nitrogenase, This system is probably also involved in maintaining the membrane in the energized state, thereby allowing nitrogen fixation to occur

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Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

International Journal of Antibiotics and Probiotics ◽

10.31405/ijap.1-2.17.03 ◽

2017 ◽

Vol 1 (2) ◽

pp. 48-60

Author(s):

A.G. Salmanov ◽

A.V. Rudenko

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Staphylococcus Epidermidis ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

Enterobacter Cloacae ◽

Proteus Vulgaris ◽

Providencia Rettgeri ◽

E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

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Prevalence and Characterization of Extended-Spectrum β-Lactamase-Producing Antibiotic-Resistant Escherichia coli and Klebsiella pneumoniae in Ready-to-Eat Street Foods

Antibiotics ◽

10.3390/antibiotics10070850 ◽

2021 ◽

Vol 10 (7) ◽

pp. 850

Author(s):

Shobha Giri ◽

Vaishnavi Kudva ◽

Kalidas Shetty ◽

Veena Shetty

Keyword(s):

Escherichia Coli ◽

Food Safety ◽

Klebsiella Pneumoniae ◽

Rural Areas ◽

Significant Risk ◽

Microbiological Quality ◽

Resistant Bacteria ◽

Antibiotic Resistant ◽

E Coli ◽

Extended Spectrum

As the global urban populations increase with rapid migration from rural areas, ready-to-eat (RTE) street foods are posing food safety challenges where street foods are prepared with less structured food safety guidelines in small and roadside outlets. The increased presence of extended-spectrum-β-lactamase (ESBL) producing bacteria in street foods is a significant risk for human health because of its epidemiological significance. Escherichia coli and Klebsiella pneumoniae have become important and dangerous foodborne pathogens globally for their relevance to antibiotic resistance. The present study was undertaken to evaluate the potential burden of antibiotic-resistant E. coli and K. pneumoniae contaminating RTE street foods and to assess the microbiological quality of foods in a typical emerging and growing urban suburb of India where RTE street foods are rapidly establishing with public health implications. A total of 100 RTE food samples were collected of which, 22.88% were E. coli and 27.12% K. pneumoniae. The prevalence of ESBL-producing E. coli and K. pneumoniae was 25.42%, isolated mostly from chutneys, salads, paani puri, and chicken. Antimicrobial resistance was observed towards cefepime (72.9%), imipenem (55.9%), cefotaxime (52.5%), and meropenem (16.9%) with 86.44% of the isolates with MAR index above 0.22. Among β-lactamase encoding genes, blaTEM (40.68%) was the most prevalent followed by blaCTX (32.20%) and blaSHV (10.17%). blaNDM gene was detected in 20.34% of the isolates. This study indicated that contaminated RTE street foods present health risks to consumers and there is a high potential of transferring multi-drug-resistant bacteria from foods to humans and from person to person as pathogens or as commensal residents of the human gut leading to challenges for subsequent therapeutic treatments.

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Resistencia antibiótica de Escherichia coli y Staphylococcus saprophyticus en la infección urinaria de un hospital público

Boletín de Malariología y Salud Ambiental ◽

10.52808/bmsa.7e5.614.010 ◽

2021 ◽

Vol 61 (4) ◽

pp. 633-641

Author(s):

Jarvis Raraz-Vidal ◽

Henry Allpas-Gomez ◽

Omar Raraz-Vidal

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

E Coli ◽

Staphylococcus Saprophyticus ◽

De Medicina

Introducción: La resistencia de antibióticos puede llegar a causar una amplia morbilidad y complicaciones. Objetivo: Determinar el perfil de resistencia antimicrobiana de Escherichia Coli y de Staphylococcus Saprophyticus, en pacientes con infección urinaria hospitalizados en el servicio de Medicina Interna del Hospital Municipal Los Olivos. Métodos: Estudio descriptivo, retrospectivo de corte transversal. Se realizó en el servicio de Medicina Interna del Hospital Municipal los Olivos (HMLO). Participantes: historia clínica de pacientes hospitalizados con infección urinaria en el servicio de Medicina Interna. Intervenciones: Según los criterios de inclusión y exclusión se obtuvieron, 96 historias clínicas (HC) del año 2013. Se utilizó un instrumento de recolección validado. Se realizó el análisis descriptivo con software estadístico STATA versión 25. Resultados: De las 96 HC, la edad promedio fue 55,04 años, los agentes microbianos más frecuentes fueron: la Escherichia coli con 85,3%, Staphylococcus saprophyticus 4.2% y Klebsiella pneumoniae 3,1%. La prevalencia de productores de betalactamasa espectro extendido (BLEE) fue 10,4%. Los antibióticos más resistentes fueron: trimetoprim/sulfametoxazol 89,6%, ampicilina 86%, piperacilina 84,6%, tetraciclina 79,2% y ciprofloxacino 70,8%. Los antibióticos más sensibles fueron: amikacina 100%, imipenem 100%, ertapenem 98%, meropenem 96% y piperacilina/tazobactam 96%. Conclusión: El uropatógeno más frecuente en pacientes con ITU hospitalizados fue la E. coli. Los antibióticos que presentaron resistencia a la E. coli fueron: trimetoprim/sulfametoxazol, ampicilina, piperacilina, tetraciclina y ciprofloxacino, y para el S. Saprophyticus fueron: amoxicilina/ ácido clavulánico, trimetoprim/sulfametoxazol, ceftriaxona y ciprofloxacino.

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Incidence and Antimicrobial Susceptibility of Escherichia coli and Klebsiella pneumoniae with Extended-Spectrum β-Lactamases in Community- and Hospital-Associated Intra-Abdominal Infections in Europe: Results of the 2008 Study for Monitoring Antimicrobial Resistance Trends (SMART)

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00265-10 ◽

2010 ◽

Vol 54 (7) ◽

pp. 3043-3046 ◽

Cited By ~ 58

Author(s):

Stephen P. Hawser ◽

Samuel K. Bouchillon ◽

Daryl J. Hoban ◽

Robert E. Badal ◽

Rafael Cantón ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Klebsiella Pneumoniae ◽

Antimicrobial Susceptibility ◽

Beta Lactamase ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Extended Spectrum ◽

Abdominal Infections

ABSTRACT From 2002 to 2008, there was a significant increase in extended-spectrum beta-lactamase (ESBL)-positive Escherichia coli isolates in European intra-abdominal infections, from 4.3% in 2002 to 11.8% in 2008 (P < 0.001), but not for ESBL-positive Klebsiella pneumoniae isolates (16.4% to 17.9% [P > 0.05]). Hospital-associated isolates were more common than community-associated isolates, at 14.0% versus 6.5%, respectively, for E. coli (P < 0.001) and 20.9% versus 5.3%, respectively, for K. pneumoniae (P < 0.01). Carbapenems were consistently the most active drugs tested.

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Antimicrobial Resistance Patterns and ESBL of Uropathogens Isolated from Adult Females in Najran Region of Saudi Arabia

Clinics and Practice ◽

10.3390/clinpract11030080 ◽

2021 ◽

Vol 11 (3) ◽

pp. 650-658

Author(s):

Mohammed Yahia Alasmary

Keyword(s):

Escherichia Coli ◽

Saudi Arabia ◽

Antimicrobial Resistance ◽

Klebsiella Pneumoniae ◽

Urine Samples ◽

Klebsiella Species ◽

E Coli ◽

Government Hospitals ◽

Resistance Patterns ◽

Tract Infections

Background: To explore the prevalence of urinary tract infections (UTIs) among female patients in the Najran region of Saudi Arabia and determine their antimicrobial resistance pattern. Methods: This study was conducted on 136 urine samples collected from outpatient departments (OPDs) of the different government hospitals in the Najran region of Saudi Arabia. Over one year, the results of susceptibility testing reports of outpatient midstream urine samples from three government hospitals were prospectively evaluated. Results: Of 136 urine samples, only 123 (90.45%) were found to show significant growth for UTIs, from which 23 different uropathogens were identified. Escherichia coli (58.5%) was the most commonly isolated organism, followed by Klebsiella pneumoniae (8.1%). The isolated microorganism showed increased resistance patterns from 3.3% to 62.6%, with an overall resistance of 27.19%. Meropenem was the most effective antimicrobial, followed by amikacin and ertapenem (0.47%, 0.91%, and 1.5% resistance, respectively). At the same time, ampicillin and cephazolin were the least (62.6% and 59.5% resistance, respectively) effective. Overall, eleven (8.94%) uropathogens isolates were ESBLs, among which there were eight (6.5%) Escherichia coli, one (0.81%) Klebsiella pneumoniae, one (0.81%) Klebsiella oxytoca, and one (0.81%) Citrobacter amalonaticus. Conclusions: E. coli remains the most commonly isolated causative uropathogens, followed by Klebsiella species. The prevalence of pathogenic E. coli and Klebsiella species underscores the importance of developing cost-effective, precise, and rapid identification systems to minimize public exposure to uropathogens. Antibiotic susceptibility data revealed that most of the isolates were resistant to the majority of the antibiotics. The patients with UTIs in the Najran region of Saudi Arabia are at a high risk of antibiotic resistance, leading to significant problems in outpatient department (OPD) treatment outcomes and raising the alarm for the physician to change their empiric treatment.

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Bactérias gram-negativas em cardeais (Paroaria coronata e Paroaria dominicana) apreendidos do tráfico de animais silvestres

Brazilian Journal of Veterinary Research and Animal Science ◽

10.11606/issn.1678-4456.v53i1p107-111 ◽

2016 ◽

Vol 53 (1) ◽

pp. 107 ◽

Cited By ~ 4

Author(s):

Marcos Paulo Vieira Cunha ◽

Marta Brito Guimarães ◽

Yamê Miniero Davies ◽

Liliane Milanelo ◽

Terezinha Knöbl

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Sao Paulo ◽

São Paulo ◽

Salmonella Spp ◽

E Coli

Anualmente o tráfico de animais silvestres retira milhões de aves da natureza. Os cardeais (Paroaria coronata) e cardeais-do-nordeste (Paroaria dominicana) estão incluídos entre as espécies de aves mais traficadas. A microbiota cloacal de passeriformes de vida livre é composta principalmente por bacilos e cocos gram-positivos, já os bacilos gram-negativos predominam em aves de cativeiro. Em situações de estresse e baixa de imunidade as bactérias gram-negativas podem causar infecções oportunistas. O presente trabalho identificou bactérias da microbiota da cloaca de 49 espécimes de P. coronata e P. dominicana apreendidas do tráfico de animais silvestres em São Paulo (SP). Foram isoladas treze espécies de bactérias gram-negativas, incluindo Salmonella spp. e Pseudomonas aeruginosa. A maior frequência de ocorrência foi de Escherichia coli, identificada em 42/49 (85,7%) das amostras fecais. Dentre os isolados de E. coli, 21/42 pertenciam aos grupos filogenéticos B2 e D, relacionados a estirpes patogênicas que causam doença extraintestinal em humanos. Klebsiella pneumoniae foi isolada em 28/49 (57,1%) das amostras. Esses resultados reforçam que as condições estressantes a que esses animais são submetidos em situações de tráfico, incluindo o contato com humanos, podem favorecer a colonização da microbiota cloacal das aves por patógenos, o que representa um risco para a sua reintrodução na natureza considerando-se o possível contato com humanos e outros animais.

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β-lactamasas de espectro extendido tipo CTX-M en aislamientos clínicos de Escherichia coli y Klebsiella pneumoniae en el Instituto Nacional de Salud del Niño-Breña, Lima, Perú

Revista Medica Herediana ◽

10.20453/rmh.v30i4.3659 ◽

2020 ◽

Vol 30 (4) ◽

pp. 242-248

Author(s):

Edgar Gonzales ◽

Lilian Patiño ◽

Elsa Ore ◽

Violeta Martínez ◽

Silvia Moreno ◽

...

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

E Coli

Objetivo: Determinar la frecuencia de β-lactamasas de espectro extendido (BLEE) en Escherichia coli y Klebsiella pneumoniae y la frecuencia de CTX-M en las productoras de BLEE en el Instituto Nacional de Salud del Niño - Breña (INSN-B). Material y métodos: Se analizaron enterobacterias productoras de BLEE del INSN-B entre los meses de agosto de 2012 y enero del 2013. Se incluyeron 724 aislamientos de Escherichia coli y 181 aislamientos de Klebsiella pneumoniae, consecutivos no repetidos, de pacientes hospitalizados y de la comunidad. La identificación se realizó por bioquímica convencional. la detección fenotípica de BLEE se hizo por el método de Jarlier y la detección genotípica de CTX-M mediante reacción en cadena de la polimerasa (PCR). Resultados: 281 (31%) de los aislamientos de ambas enterobacterias fueron productoras de BLEE; 207/724 (28,6%) E. coli y 74/181 (40,9%) K. pneumoniae. Se detectó el gen blaCTX-M en 256 de los aislamientos productores de BLEE (91,1%). Conclusiones: Las BLEE de tipo CTX-M están presentes en nuestra institución, a pesar que nuestros datos representan una sola institución, brinda parte del panorama nacional sobre la resistencia a los antimicrobianos; por lo tanto, el enfoque de epidemiológico molecular es importante para desarrollar más y mejores estrategias de control y manejo de estos patógenos en nuestro país.

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

Ciência Animal Brasileira ◽

10.1590/1089-6891v20e-47632 ◽

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.

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