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Phytomedicines Targeting Antibiotic Resistance through Quorum Sensing and Biofilm Formation Associated with Acne Vulgaris
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Isa A. Lambrechts, Namrita Lall
As commensal bacteria, S. epidermidis and C. acnes play essential roles in protecting the skin from pathogenic microbes in two ways, indirectly and directly. These commensal bacteria compete with pathogens for resources such as space and nutrients, limiting the growth of these harmful microorganisms. Directly, commensal bacteria produce antimicrobial compounds called bacteriocins that directly restrict the growth of the pathogens. These proteinaceous factors inhibit the growth of closely related bacterial species, but with no effect on the organism that produces them. Staphylococcus epidermidis is a skin commensal bacteria, as well as an opportunistic pathogen, and it has been shown to cause serious infections in humans. The bacteria releases several bacteriocins that inhibit the growth of various pathogens, including one within the same genus, Staphylococcus aureus (Sanford and Gallo, 2013).
Complications of open repair of ruptured abdominal aortic aneurysm
Published in Sachinder Singh Hans, Mark F. Conrad, Vascular and Endovascular Complications, 2021
Aortic graft infections are often difficult to diagnose as the patient may present with nonspecific symptoms such as generalized weakness, malaise, anorexia, back pain, and unexplained weight loss. Occasionally, the patient may present with overt sepsis.8 The laboratory and diagnostic studies are often nonspecific but may include leukocytosis with a shift to the left, elevated C-reactive protein and sedimentation rate. Blood culture may not give positive results. Common pathogens include Staphylococcus aureus and Staphylococcus epidermidis. Staphylococcus epidermidis infection produces biofilm and attracts foreign bodies like prosthetic graft. Biofilm contains a large number of persistent cells that protect the microorganism against neutrophil-dependent killing and complement system inactivation via deposition of C3b and immunoglobin G. Imaging studies such as CTA aid in confirming the diagnosis and help in evaluating the extent of infection.
Commensal Flora
Published in Firza Alexander Gronthoud, Practical Clinical Microbiology and Infectious Diseases, 2020
The bacterial flora on the skin protects individuals against colonization by pathogens. Conversely, skin flora can become pathogenic if the organisms penetrate the skin (e.g. when there is a wound). Cellulitis and erysipelas are predominantly caused by S. aureus and Streptococcus pyogenes. Staphylococcus epidermidis is a common skin colonizer and not associated with wound infections. However, this species may cause bloodstream infections in the presence of indwelling devices. Patients who receive chemotherapy for treatment of their underlying malignancy are at risk for mucositis, which increases the risk of bacterial translocation with gut flora. Patients with graft-versus-host disease affecting the skin or gut are at risk for infection.
How to best manage a patient with Bacillus endophthalmitis: current insights
Published in Expert Review of Ophthalmology, 2021
Amin Ahmadi, Mohammad Soleimani, Ali A. Haydar, Shima Moslemi Haghighi
Endophthalmitis is a highly devastating intraocular infection that frequently leads to blindness. If not treated adequately, endophthalmitis can progress to panophthalmitis – necessitating evisceration or enucleation of the eye. Endophthalmitis can be categorized into postoperative, post-traumatic, or endogenous [1]. In a major review on the microbial causes of endophthalmitis, 85.1% of pathogens were identified as gram-positive bacteria, 10.3% gram-negative, and 4.6% fungi [2]. Overall, Staphylococcus epidermidis is the most common identified pathogen [2]. Acute postoperative endophthalmitis and post intravitreal endophthalmitis are most caused by Staphylococcus epidermidis, whereas Staphylococci and Bacillus cereus are the most common cause of posttraumatic endophthalmitis [1,3,4]. The prevalence of posttraumatic endophthalmitis ranges from 0.9% to 11.9% [5–8], with much higher figures in case of intraocular foreign body (IOFB) injuries, 6.9% to 30% [9–11]. Endogenous endophthalmitis is mainly caused by Staphylococcus aureus and Streptococci when associated with endocarditis, and by Klebsiella pneumoniae when associated with liver abscess. Endogenous fungal endophthalmitis is common in hospitalized patients, mainly due to Candida albicans [1].
Dual loading of Nigella sativa oil-atorvastatin in chitosan–carboxymethyl cellulose nanogel as a transdermal delivery system
Published in Drug Development and Industrial Pharmacy, 2021
Fereshteh Bagheri, Sara Darakhshan, Saharnaz Mazloomi, Behrang Shiri Varnamkhasti, Reza Tahvilian
Staphylococcus epidermidis and Staphylococcus aureus are considered as two common skin bacteria [29]. Both strains were obtained from the hospital, separately cultured in tryptic soy broth (TSB) medium along with 0.6% yeast extract, and then maintained at shaker incubator with 150 rpm for 24 h at 37 °C. Afterward, the bacteria were suspended at sterile PBS (pH 7.2), centrifuged, and resultant precipitate was re-suspended in PBS. Disc diffusion method was performed for antimicrobial evaluation of NGs. The appropriate counts for each bacterium were separately cultured on the plates containing TSB by sterile swab. Blank paper disks with a diameter of 6 mm were placed on plates of positive control (tetracycline), negative control (blank), with the concentration ranges of 10, 20, 50, and 100 µl of each BNG, ONG, and ATONG. Results of the ONG or ATONG groups were compared with the BNG group. The plates were incubated for 24 h at 37 °C. If bacteria are placed on the agar they will not grow on the area around the disc, if they are susceptible to the compounds. In this regard, this area of no growth around the disc is known as a ‘Zone of inhibition’. The zone diameters were measured by slipping calipers of National Committee for Clinical Laboratory Standards [30].
Does intraoperative contamination during primary knee arthroplasty affect patient-reported outcomes for patients who are uninfected 1 year after surgery? A prospective cohort study of 714 patients
Published in Acta Orthopaedica, 2020
Tobias Justesen, Jakob B Olsen, Anne B Hesselvig, Anne Mørup-Petersen, Anders Odgaard
At the start of analyzing data for this study May 2019, 1,499 patients were included in either the SPARK study, the ICON study, or both studies (Figure 2). 766 patients were only included in either the ICON or SPARK study due to different enrollment centers and enrollment periods and were thus excluded. 19 patients were excluded due to PJIs or revision surgery. 2 of the 12 patients excluded due to PJIs were intraoperatively contaminated. 1 patient was contaminated with Micrococcus species while joint fluid and biopsy at revision surgery showed Streptococcus dysgalactiae. The other patient was contaminated with Staphylococcus capitis and epidermidis, and joint fluid and biopsy at revision surgery revealed Staphylococcus epidermidis. None of the 7 patients who underwent revision surgery, for reasons other than PJIs, were intraoperatively contaminated. Furthermore, none of the intraoperative biopsies from the revisions, which were done on 4 of the patients on the slightest suspicion of infection, revealed any positive culture. The reasons for revision surgery were: rupture of the posterior cruciate ligament, medial tibial plateau fracture, instability, loosening of the prosthesis, progression of arthrosis, and in 2 cases pain and instability. A sufficient PRO sequence and contamination data were available for 714 patients (389 women and 325 men), who were included in the final analysis.