Surgical infection
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie in Bailey & Love's Short Practice of Surgery, 2018
This condition is not caused by clostridia. A mixed pattern of organisms is responsible: coliforms, staphylococci, Bacteroides spp., anaerobic streptococci and peptostreptococci have all been implicated, acting in synergy. Often, aerobic bacteria destroy the living tissue, allowing anaerobic bacteria to thrive. Abdominal wall infections are known as Meleney's synergistic gangrene and scrotal infections as Fournier's gangrene (Figure5.12). Patients are almost always immunocompromised, with conditions such as diabetes mellitus. The wound initiating the infection may have been minor, but severely contaminated wounds are more likely to be the cause. Severe wound pain, signs of spreading inflammation with crepitus and smell are all signs of the infection spreading. Untreated, it will lead to widespread local gangrene and systemic multisystem organ failure. The subdermal spread of gangrene is always much more extensive than appears from initial examination. Broad-spectrum antibiotic therapy must be combined with aggressive circulatory support. Locally, there should be wide excision of necrotic tissue and laying open of affected areas. The debridement may need to be extensive, and patients who survive may need large areas of skin grafting.
Lymphangitis
Waldemar L. Olszewski in Lymph Stasis: Pathophysiology, Diagnosis and Treatment, 2019
The aerobic bacteria counts per square centimeter aie on the palm of hand 6.6 × 10 to 5.6 × 103, on the forearm 3.3 × 10 to 5.3 × 103, on the sole of foot 7.2 × 10 to 1.6 × 104, on the dorsum of foot 3.3 × 10 to 5.4 × 103, on the calf 0.5 × 104, and on the thigh 9.9 × 10 to 2.0 × 104. The highest numbers of microbes are obtained from forehead and axilla, 2.4 × 106/cm2 and 2 × 105/cm2, respectively. The majority of aerobic bacteria were bound at or near the surface. Even when the transient bacteria are removed by washing, the majority of remaining microbes are still found in the outer 0.3 mm. The main site of residence, especially the diphtheroids, are the sebaceous glands and hair follicles. The skin flora is composed of large microcolonies separated by many microns. The number of cells in a microcolony ranges from 100 to 70,000. Sweat glands are usually free of bacteria. In histopathological pictures bacteria can be found in infundibulum of hair follicles.
Meropenem and Meropenem–Vaborbactam
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Gram-negative aerobic bacteria have become one of the most formidable challenges to maintaining the efficacy of antibiotics. Meropenem remains highly active toward the majority of aerobic Gram-negative bacteria (Table 38.2), with stability against many problematic beta-lactamases, including extended-spectrum beta-lactamases (ESBLs) and AmpC-type beta-lactamases. Meropenem has generally been considered first-line therapy for serious infections caused by such or-ganisms (Paterson et al., 2004). Compared to other carbapenems, the In vitro potency of meropenem is 4-to 16-fold greater than that of imipenem (Turner, 2007), and was reported to have a 2-to 8-fold greater In vitro potency toward ESBLs than ertapenem when ertapenem MICs were ≥ 2 μg/ml (Rhomberg et al., 2007). However, increasing carbapenem use in response to the rising global incidence of multidrug resistant Gram-negative bacilli may be a key driver in the emergence of carbapenem resistance (van Boeckel et al., 2014). As such, there is renewed interest in carbapenem-sparing alternatives for the treatment of ESBL or AmpC-producers (Harris et al., 2015).
Organization of supragingival plaque at the micron scale
Published in Journal of Oral Microbiology, 2018
Mark Welch et al. [1] reported that supragingival biofilm from 22 healthy volunteers consisted of a radially arranged, nine-taxon structure that was established around cells of filamentous corynebacteria. This bacterial consortium had a radius ranging from a few tens to a few hundreds of microns and was spatially differentiated. The authors described it as a hedgehog structure due to its filaments. The localization of the different taxa here suggested that they had specific functions in the consortium. As expected, anaerobic bacteria tended to localize in the interior where oxygen tension is low while facultative anaerobic and obligate aerobic bacteria tended to be at the periphery of the consortium (Figure 1). Consumers of sugars and oxygen such as streptococci produce metabolites like lactate, CO2, and H2O2 and tended to localize close to each other. Even if these were the most characteristic and reproducible features of the plaque structure, there was a spatial, temporal, and individual variation in the abundance of hedgehogs and other types of consortia in the supragingival plaque.
Dental aerosols: microbial composition and spatial distribution
Published in Journal of Oral Microbiology, 2020
C. Zemouri, C.M.C. Volgenant, M.J. Buijs, W. Crielaard, N.A.M. Rosema, B.W. Brandt, A.M.G.A. Laheij, J.J. De Soet
A large proportion of the air samples, from our study, that were taken before treatment, after treatment and during treatment at the control location did not meet the criteria for clean air (guidelines for clean air: SS EN ISO 14,698–1:2003). Only the university clinic met these criteria (<2 CFU/plate in 30 minute exposure time). Increased microbial air contamination was particularly found during treatment at the patient’s chest. This zone also contained the highest number of taxa, mainly from human origin. Close to the treatment site, aerobic bacteria were present in equal amounts to anaerobic bacteria. Locations further away from the patient contained significantly more aerobic bacteria than anaerobic bacteria, suggesting their origin is less likely to come from the dental treatment. The results of our study indicate that contamination of the aerosols from both human and water origin during treatment mostly settle in the close proximity of the head of the patient. This is in line with a previous study [25], although other studies reported no difference in microbial counts near the patient’s head and at further distance from the treatment zone [11,26].
Epidemiology and antibiotic susceptibility in anaerobic bacteraemia: a 15-year retrospective study in South-Eastern Hungary
Published in Infectious Diseases, 2022
Károly Péter Sárvári, Nóra Bernadett Rácz, Katalin Burián
The incubation of aerobic and anaerobic BC bottles (bioMérieux, France) was performed in the BacT/ALERT® VIRTUOTM automated incubation system (bioMérieux, France). The anaerobic isolates were cultured on Schaedler agar (bioMérieux, France) for 48 h, at 37 °C in an anaerobic chamber (Perkin Elmer, UK) under anaerobic conditions (85% N2, 10% CO2, 5% H2). The aerobic bacteria were cultured on Columbia (with 5% sheep's blood), chocolate, and eosin methylene blue agar plates (bioMérieux, France), while the fungal isolates were cultured on Sabouraud agar plates (bioMérieux, France) at 35 °C for 24 h. The identification of the strains, isolated between 1 January 2004 and 31 December 2012 was performed with VITEK2 ANC cards (bioMérieux, France). The identification of those strains, which were isolated between 1 January 2013 and 31 December 2018, was performed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) (Bruker Daltonik, Germany) using Biotyper Version 3.0 software. After measurement, if the log score value was ≥2.000 of the isolate, it was considered as reliable species-level identification.
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