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Aztreonam and Aztreonam-Avibactam
Published in 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, Kucers’ The Use of Antibiotics, 2017
Wild-type Pseudomonas aeruginosa strains are typically aztreonam susceptible, but ceftazidime and other antipseudomonal beta-lactam antibiotics are more active. Approximately one third of contemporary P. aeruginosa strains are nonsusceptible to aztreonam (Fritsche et al., 2005; Sader et al., 2005; Biedenbach et al., 2015; Testa et al., 2015). Aeromonas spp. are aztreonam sensitive (Morita et al., 1994; Fritsche et al., 2005). Burkholderia cepacia and P. stutzeri are usually sensitive, but the Acinetobacter spp., Brevundimonas diminuta, P. putida, Stenotrophomonas maltophilia, and Chryseobacterium spp. are aztreonam resistant (Jacobus et al., 1982; Strandberg et al., 1983; Tunkel and Scheld, 1990; Chang et al., 1997; Fritsche et al., 2005; Sader et al., 2005; Wang et al., 2014; Biedenbach et al., 2015; Testa et al., 2015).
Protein-Based Bioscavengers of Organophosphorus Nerve Agents
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Moshe Goldsmith, Yacov Ashani, Tamara. C. Otto, C. Linn Cadieux, David. S. Riddle
Phosphotriesterase (PTE), also termed organophosphate hydrolase (OPH) (EC 3.1.8.1), is a 336-amino acid (36 kDa), zinc-dependent hydrolase, structured as an (αβ)8 TIM-barrel (Benning et al., 1994). It is a bacterial enzyme that belongs to the amidohydrolase superfamily and was first identified in soil bacteria that hydrolyzed the pesticide parathion (Serdar et al., 1982). Since man-made OP pesticides were introduced into the environment only in the 1950s, and since its catalytic efficiency of hydrolysis approaches the diffusion limit (e.g., kcat/KM ~ 109 M−1 min−1 with paraoxon), it was suggested that PTE is the product of the recent and rapid natural evolution of a lactonase (Afriat-Jurnou et al., 2012; Afriat et al., 2006). PTE is encoded on a natural plasmid (pCMS1) in a bacterial strain that was originally classified as Pseudomonas diminuta strain MG (Serdar and Gibson, 1985; Serdar et al., 1982) and later reclassified as Brevundimonas diminuta (Segers et al., 1994). The fact that the gene encoding PTE (opd) was found on a plasmid meant that it could be transferred to other bacterial strains. Indeed, PTE was also found independently in unrelated soil bacteria isolated from different parts of the world, such as Sphingobium fuliginis (former Flavobacterium sp. ATCC 27551) identified in the Philippines (Kawahara et al., 2010; Mulbry and Karns, 1989; Sethunathan and Yoshida, 1973) and Brevundimonas diminuta and Pseudomonas putida, identified in the United States (Iyer et al., 2013b; Serdar et al., 1982). Plasmid pCMS1 from B. diminuta was found to be self-transmissible and responsible for the horizontal transfer of its opd gene between soil bacteria (Pandeeti et al., 2011). OP pesticides can become a valuable source of phosphorus for soil bacteria. However, they need to be imported into the cell and degraded to simpler molecules, such as phosphoric acid, to be used for growth and energy. Accordingly, the expression of PTE from B. diminuta was found to be targeted to the inner membrane of the bacteria, where it becomes membrane bound and associated with phosphatases and with a phosphate transporter (Parthasarathy et al., 2016).
Bacteriology of Ophthalmic Infections
Published in K. Balamurugan, U. Prithika, Pocket Guide to Bacterial Infections, 2019
Arumugam Priya, Shunmugiah Karutha Pandian
Perceptive features of the ocular microflora are fundamental in understanding the ocular diseases and infections. Axenfeld (1908) stated that the microbiota of eyelid and conjunctiva are similar to that of the skin and upper respiratory tract. Since then, microbial flora of the ocular surface has been subjected to numerous studies to investigate the indigenous flora of the healthy eyes, as a comparative analysis to interpret the microbial shift during diseased state, to assess the microbial community before intraocular surgeries, or to review the prophylactic strategies in postoperative infections. Axenfeld founds that Staphylococcus albus and Corynebacterium were frequently isolated organisms, whereas Staphylococcus aureus, Streptococcus spp., and few other gram-negative bacteria were found with least incidence. The classification of ocular microbiota based on the culture-dependent methods was alleged to be predominantly conquered by gram-positive species such as Staphylococcus, Streptococcus, Propionibacterium, and Corynebacterium; gram-negative species such as Neisseria, Haemophilus, and few fungal species (Miller and Iovieno, 2009). Culture-based characterization significantly surpassed cultivable and fastidious growing organisms. With the advent of molecular techniques, (Dong et al., 2011) instigated the genome based detection of ocular microbiota and revealed diverse microbial community including commensal, environmental, and opportunistic pathogens (Dong et al., 2011). The 12 genera, Pseudomonas, Propionibacterium, Bradyrhizobium, Corynebacterium, Acinetobacter, Brevundimonas, Staphylococci, Aquabacterium, Sphingomonas, Streptococcus, Streptophyta, and Methylobacterium, were represented as core microbiome of the conjunctiva. Based on the sequencing of 16S rDNA V3–V4 hypervariable segments of bacteria from conjunctival swab, Huang et al. (2016) linked additional genera such as Millisia, Anaerococcus, Finegoldia, Simonsellia, and Veillonella to the core conjunctival microbiota. Numerous studies have evidenced that the use of contact lenses (Hovding, 1981; Larkin and Leeming, 1991; Fleiszig and Efron, 1992; Iskeleli et al., 2005; Shin et al., 2016), the eyes that endured surgeries (Jabbarvand et al., 2016) and patients with prolonged hospital stays (Sahin et al., 2017) presented variations in the microbial diversity and abundance. Moreover, variation in the ocular microbiota between eyes of an individual and between individuals has also been affirmed (Hovding, 1981).
Drip irrigation biofouling with treated wastewater: bacterial selection revealed by high-throughput sequencing
Published in Biofouling, 2019
Kévin Lequette, Nassim Ait-Mouheb, Nathalie Wéry
Genus-level analysis of TWW bacterial composition revealed that uncultured members of the order Burkholderiales (MWH-UniP1 aquatic group: 5%), the class Actinobacteria (PeM15_ge: 5%) and the order Chlorobiales (SJA-28_ge: 3%) were the genera with the highest relative abundances (Table 3). Bacterial communities of pipe samples were dominated by the genera Aeromicrobium (10%), Brevundimonas (5%) and Chryseobacterium (5%). In dripper biofilms, the dominant genera were Aquabacterium, with a mean relative abundance of 14%, and Terrimonas, with a mean relative abundance of 9% (Table 3).
A rare case of peritonitis due to Brevundimonas vesicularis
Published in Journal of Community Hospital Internal Medicine Perspectives, 2018
This organism has been an uncommon cause of infection, and review of literature performed in 2011 by Shang et al. [6] found only 15 cases of Brevundimonas that caused bacteremia in hospitalized patients. One such case report was a 55-year-old patient, first reported by Choi et al. 2006, who developed peritonitis while on peritoneal dialysis [7]. This was the first reported incident of peritonitis caused by B. vesicularis. We believe that our patient is a second case of peritonitis caused by B. vesicularis in the setting of peritoneal dialysis.
Growth of Cutibacterium acnes is common on osteosynthesis material of the shoulder in patients without signs of infection
Published in Acta Orthopaedica, 2018
Anna Both, Till O Klatte, Andreas Lübke, Henning Büttner, Maximilian J Hartel, Lars G Grossterlinden, Holger Rohde
Patient 30 showed additional growth of S. epidermidis and S. capitis on the osteosynthesis material and P. mirabilis in 1 tissue sample, while samples from Patient 6 showed additional growth of Brevundimonas sp. and Kocuria sp. Foreign materials of Patient 36 grew S. saccharolyticus in addition to C. acnes. The non-C. acnes species in Patients 6, 30, and 36 were grown in very low numbers, thus they might constitute contamination during removal from the body or microbiological workup (Table).