Epidemiology of Acinetobacter spp.: Surveillance and Management of Outbreaks
E. Bergogne-Bénézin, M.L. Joly-Guillou, K.J. Towner in Acinetobacter, 2020
Infected or colonised patients seem to be the primary reservoir of A. baumannii in hospitals, and contaminated equipment is a frequent source of infections; however, the way(s) in which the organism spreads from patient to patient is less clear. As indicated previously, staff hand carriage from contact with an infected patient is the most likely mode of transmission, which may also involve indirect hand contamination from contact with inanimate objects. Musa et al. (1990) studied the survival of A. baumannii and A. Iwoffii on human skin (Figure 4.4). There is evidence to suggest that Acinetobacter survives better on fingertips than other Gram-negative bacilli such as Klebsiella aerogenes, E. coli, S. marcescens and P. aeruginosa (Casewell and Desai, 1983; Ayliffe et al., 1988). From an Acinetobacter inoculum of about 2 x 106 cfu/finger, up to 102 cfu/finger were recovered 1 h after inoculation. The relatively short survival time observed on fingertips, compared to survival on dry surfaces, has been attributed to antimicrobial action on the surface of palmar skin. However, even survival for 1 h on skin provides ample opportunity for transmission in the absence of appropriate hand-washing and disinfection procedures.
Acanthamoeba
Dongyou Liu in Laboratory Models for Foodborne Infections, 2017
Acanthamoeba undergoes two stages of development in its life cycle: motile trophozoite and dormant cyst. Trophozoites (Greek “tropho” means “to nourish”) actively feed on bacteria (e.g., Escherichia coli K-12, Klebsiella aerogenes), algae, yeast, and other protozoa in the environment through pseudopod formation, phagocytosis, or food cup formation, and are infective to humans. In addition, trophozoites are capable of living axenically on nutrients in liquid through pinocytosis. The locomotion of trophozoites involves the formation of hyaline pseudopodia (acanthopodia), and trophozoites divide mitotically (through binary fission) under optimal conditions (food supply, neutral pH, ~30°C, and 50–80 mOsmol). Acanthamoeba forms dormant cyst with a resistant double-layer wall under harsh conditions, facilitating its long-term survival under extreme temperatures and pH, desiccation, and chemical exposure [2].
Consideration of Glutamine Synthetase as a Multifunctional Protein
James F. Kane in Multifunctional Proteins: Catalytic/Structural and Regulatory, 2019
The glutamine synthetase from Escherichia coli has been extensively studied and the information reviewed.4,7 Although there are properties that differ for the glutamine synthetases from E. coli, Salmonella typhimurium, Klebsiella aerogenes, and K. pneumoniae, the characteristics described for the enzyme from E. coli are generally applicable to these proteins.8 The enzyme has a molecular weight of 600,000 daltons and is composed of 12 identical subunits with a molecular weight of about 50,000 daltons each. Electron micrographs of purified glutamine synthetase show that the subunits are arranged in a hexagonal bilayer with a layer of six subunits superimposed on the other.6,9 These bilayered molecules can polymerize face to face, to form long strands which wind around each other to form three- and seven-stranded cables.10,11
Orbital cellulitis and cavernous sinus thrombosis with contralateral sinus disease in a COVID-19 positive adolescent patient
Published in Orbit, 2023
Amelia S. Lawrence, David G. Stoddard, Craig N. Czyz, Thomas E. Richardson, Kevin S. Michels
The patient underwent urgent surgical intervention with comprehensive endoscopic sinus surgery including frontal sinusotomy, total ethmoidectomy, sphenoidotomy with tissue removal, maxillary antrostomy with tissue removal and left medial orbital decompression. While doing an isolated medial wall decompression via an orbital approach might be considered controversial in the setting of CST, there is a greater level of precision offered via the sinus endoscopic approach that negates the majority of the potential complications one might encounter from an orbital approach. Further, the clinical decision to open the left medial orbital wall was made in an attempt to reduce the likelihood of orbital abscess formation. Purulence cultured from the sinuses was positive for Klebsiella aerogenes and Streptococcus intermedius, but multiple blood cultures were negative.
Increasing incidence of pyogenic liver abscess in Southern Sweden: a population-based study from 2011 to 2020
Published in Infectious Diseases, 2023
Emma Svensson, Astrid Jönsson, Anna Bläckberg, Torgny Sunnerhagen, Ali Kiasat, Oskar Ljungquist
Blood cultures were obtained in 93% (n = 350) of all episodes of PLA and 54% (n = 188) were positive (Supplementary Table A2). Monomicrobial results were found in 73% (n = 138) of blood cultures, and the most common pathogens were Streptococcus spp. 29%, n = 40), E. coli (19%, n = 26) and Klebsiella spp. (17%, n = 24). The most common Streptococcus species belonged to the Streptococcus anginosus complex (n = 37, 93%). Klebsiella species found were Klebsiella pneumoniae (15%, n = 21), Klebsiella oxytoca group (1%, n = 2) and Klebsiella aerogenes (1%, n = 1; Supplementary Table A3).
Pyogenic liver abscess after open hemorrhoidectomy
Published in Acta Chirurgica Belgica, 2023
Maxim Peeters, Xavier De Raeymaeker, Amine Karimi, Martijn van der Pas
At day 2, at transthoracic ultrasound was performed. This showed no signs suggestive for endocarditis. A transesophageal ultrasound was not performed. The renal function was recovered (creatinine 0,75 mg/dL). Since there was neck stiffness with photophobia at day 2, a computed tomography (CT) of the brain was performed together with a lumbar puncture. The CT scan was normal. The lumbar puncture and all other blood cultures stayed negative. Rectal screening swab showed klebsiella aerogenes which is an extended spectrum beta-lactamase producing enterobacteria (ESBL).
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