Identifying gram-positive cocci in dermatoscopes and smartphone adapters using MALDI-TOF MS: a cross-sectional study

Abstract Background: The increasingly frequent use of dermoscopy makes us think about the possibility of transfer of microorganisms, through the dermatoscope, between doctor and patients. Objectives: To identify the most frequent gram-positive cocci in dermatoscopes and smartphone adapters, as well as the resistance profile, and to evaluate the factors associated with a higher risk of bacterial contamination of the dermatoscopes. Methods: A cross-sectional study was carried out with 118 dermatologists from Porto Alegre/Brazil between September 2017 and July 2018. Gram-positive cocci were identified by MALDI-TOF MS and habits of use of the dermatoscope were evaluated through an anonymous questionnaire. Results: Of the dermatoscopes analysed, 46.6% had growth of gram-positive cocci on the lens and 37.3% on the on/off button. The microorganisms most frequently found were S. epidermidis, S. hominis and S. warneri. Attending a hospital, using the dermatoscope at the hospital, with inpatients and in the intensive care unit were significantly associated with colonisation by gram-positive cocci. The highest resistance rates were observed for penicillin, erythromycin and sulfamethoxazole-trimethoprim. Study limitations: The non-search of gram-negative bacilli, fungi and viruses. Moreover, the small number of adapters did not make it possible to better define if the frequency differences were statistically significant. Conclusion: Coagulase-negative staphylococci were frequently identified. S. aureus was detected only on the lens.

A Patient with Pediatric Septic Arthritis of the Hip Complicated with Osteomyelitis Responds to Clindamycin.

A 5-year-old girl was referred to our institution with complaints of right hip pain and fever (39.0°C); blood tests and magnetic resonance imaging (MRI) were performed. Blood biochemical results revealed a high inflammatory reaction. MRI results revealed inflammation in the hip joint. She was diagnosed with pediatric septic arthritis of the hip, which required arthrotomy and lavage drainage. Treatment with intravenous vancomycin was initiated on the assumption that the causative bacterial species was Staphylococcus aureus. However, Group A Streptococcus pyogenes (GAS) was subsequently isolated from an intraoperative sample, and the antimicrobial agent was switched to aminobenzylpenicillin (ABPC). Clindamycin (CLDM) was added to the treatment regimen 14 days after surgery as MRI indicated the development and spread of osteomyelitis. Three months post-surgery, MRI findings indicated that the osteomyelitis had resolved and antimicrobial therapy was discontinued. To prevent the spread of osteomyelitis, a combination of CLDM and ABPC should be considered at an early stage, particularly in pediatric patients with GAS-induced septic arthritis.

Is it possible to perform bacterial identification and antimicrobial susceptibility testing with a positive blood culture bottle for quick diagnosis of bloodstream infections?

Abstract INTRODUCTION: Bloodstream infections can be fatal, and timely identification of the etiologic agent is important for treatment. METHODOLOGY: An alternative method, consisting of direct identification and susceptibility testing of blood culture bottles using the automated VITEK 2® system, was assessed. RESULTS: All 37 of the Gram-negative bacilli (GNB) identifications and 57.1% of the 28 Gram-positive cocci (GPC) identifications matched those obtained with standard methods. In susceptibility testing, the agreement was greater than 90%. CONCLUSIONS: This alternative methodology may assist in the early identification and susceptibility testing of GNB. Further research is necessary to develop appropriate methods for GPC.

Urinary tract infections following radical cystectomy and urinary diversion: a review of 1133 patients.

OBJECTIVE: To investigate the incidence and microbiology of urinary tract infection (UTI) within 90 days following radical cystectomy (RC) and urinary diversion. METHODS: We reviewed 1133 patients who underwent RC for bladder cancer at our institution between 2003 and 2013; 815 patients (72%) underwent orthotopic diversion, 274 (24%) ileal conduit, and 44 (4%) continent cutaneous diversion. 90-day postoperative UTI incidence, culture results, antibiotic sensitivity/resistance and treatment were recorded through retrospective review. Fisher's exact test, Kruskal-Wallis test, and multivariable analysis were performed. RESULTS: A total of 151 urinary tract infections were recorded in 123 patients (11%) during the first 90 days postoperatively. 21/123 (17%) had multiple infections and 25 (20%) had urosepsis in this time span. Gram-negative rods were the most common etiology (54% of positive cultures). 52% of UTI episodes led to readmission. There was no significant difference in UTI rate, etiologic microbiology (Gram-negative rods, Gram-positive cocci, fungi), or antibiotic sensitivity and resistance patterns between diversion groups. Resistance to quinolones was evident in 87.5% of Gram-positive and 35% of Gram-negative bacteria. In multivariable analysis, Charlson Comorbidity Index > 2 was associated with higher 90-day UTI rate (OR = 1.8, 95% CI 1.1-2.9, p = 0.05) and Candida UTI (OR 5.6, 95% CI 1.6-26.5, p = 0.04). CONCLUSIONS: UTI is a common complication and cause of readmission following radical cystectomy and urinary diversion. These infections are commonly caused by Gram-negative rods. High comorbidity index is an independent risk factor for postoperative UTI, but diversion type is not.

Antimicrobial activity of different disinfection methods against biofilms in root canals.

AIM: The aim of the present study was to evaluate the bactericidal effects of different disinfection methods against microbial biofilms grown in root canals. METHODS: A total of 300 freshly-extracted human teeth were infected with microbial pathogens. The biofilm formation and the effects of laser therapy, photodynamic therapy (PDT), iontophoresis, and disinfection with irrigating solutions were evaluated by counting the generations of microbial cells in the samples of root canals and by scanning electron microscopy. RESULTS: Enterococcus faecalis and other Gram-positive cocci demonstrated highest sensitivity to the methods of antibacterial action compared here. In most of the cases observed, the antibacterial treatment was less effective against Gram-negative bacteria in dental biofilms. The biofilms that were most difficult to eliminate were those formed by Pseudomonas aeruginosa. Iontophoresis treatment with iodine and chemical disinfection with hypochlorite and chlorhexidine demonstrated the most powerful bactericidal effect. When PDT was applied with Fotosan as a photosensitizer, better disinfection was achieved in comparison to the other lasers alone. CONCLUSION: The comparison of these different strategies for endodontic treatment showed that hypochlorite, followed by the chlorhexidine irrigant in our experimental conditions, gave the most satisfactory results against the formation of bacterial biofilms in the root canals.

Case-Control Study of Telavancin as an Alternative Treatment for Gram-Positive Bloodstream Infections in Patients with Cancer.

Gram-positive bacterial infections are an important cause of morbidity and death among cancer patients, despite current therapy. In this case-control study, we evaluated the clinical outcomes and safety of telavancin in cancer patients with uncomplicated Gram-positive bloodstream infections (BSIs). Between March 2011 and May 2013, we enrolled cancer patients with uncomplicated Gram-positive BSIs to receive intravenous telavancin therapy for at least 14 days for Staphylococcus aureus and 7 days for other Gram-positive cocci. Patients with baseline creatinine clearance (CLCR) values of >50 ml/min received 10 mg/kg/day of telavancin, and those with CLCR values between 30 and 49 ml/min received 7.5 mg/kg/day. Patients were compared with a retrospective cohort of 39 historical patients with Gram-positive BSIs, matched for underlying malignancy, infecting organism, and neutropenia status, who had been treated with vancomycin. A total of 78 patients were analyzed, with 39 in each group. The most common pathogen causing BSIs was S. aureus (51%), followed by alpha-hemolytic streptococci (23%), Enterococcus spp. (15%), coagulase-negative staphylococci (8%), and beta-hemolytic streptococci (3%). Sixty-two percent of patients had hematological malignancies, and 38% had solid tumors; 51% of the patients were neutropenic. The overall response rate determined by clinical outcome and microbiological eradication at 72 h following the initiation of therapy, in the absence of relapse, deep-seated infections, and/or infection-related death, was better with telavancin than with vancomycin (86% versus 61%; P = 0.013). Rates of drug-related adverse events were similar in the two groups (telavancin, 31%; vancomycin, 23%; P = 0.79), with similar rates of renal adverse events. Telavancin may provide a useful alternative to standard vancomycin therapy for Gram-positive BSIs in cancer patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT01321879.).

Resistencia a antibióticos de última línea en cocos Gram positivos: la era posterior a la vancomicina / Resistance to "last resort" antibiotics in Gram-positive cocci: The post-vancomycin era

En los últimos años se han desarrollado nuevas alternativas para el tratamiento de infecciones por patógenos Gram positivos multirresistentes, entre los cuales Staphylococcus aureus resistente a la meticilina (SARM) y los enterococos resistentes a la vancomicina (ERV) se consideran un verdadero reto terapéutico, y aunque el uso de la vancomicina en infecciones graves causadas por SARM ha generado serias dudas en los últimos años, continúa siendo escasa la información clínica de respaldo al uso de agentes terapéuticos que la superen en eficacia. El linezolid, la daptomicina y la tigeciclina son agentes que tienen actividad contra los cocos Gram positivos y que fueron aprobados e introducidos en la terapia clínica en la década pasada. Además, se han probado o están en las fases finales de desarrollo otros agentes como las cefalosporinas de última generación (ceftarolina y ceftobiprol). El propósito de esta revisión fue describir las nuevas alternativas terapéuticas, particularmente en la era posterior a la vancomicina, y repasar las características químicas más relevantes de los compuestos y su espectro de actividad, haciendo énfasis en sus mecanismos de acción y resistencia.

New therapeutic alternatives have been developed in the last years for the treatment of multidrug-resistant Gram-positive infections. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are considered a therapeutic challenge due to failures and lack of reliable antimicrobial options. Despite concerns related to the use of vancomycin in the treatment of severe MRSA infections in specific clinical scenarios, there is a paucity of solid clinical evidence that support the use of alternative agents (when compared to vancomycin). Linezolid, daptomycin and tigecycline are antibiotics approved in the last decade and newer cephalosporins (such as ceftaroline and ceftobiprole) and novel glycopeptides (dalvavancin, telavancin and oritavancin) have reached clinical approval or are in the late stages of clinical development. This review focuses on discussing these newer antibiotics used in the "post-vancomycin" era with emphasis on relevant chemical characteristics, spectrum of antimicrobial activity, mechanisms of action and resistance, as well as their clinical utility.

Effects of intranasal steroid treatment on the presence of biofilms in non-allergic patients with chronic rhinosinusitis with nasal polyposis.

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal application of corticosteroids (INCS) is a reliable option in the management of CRSwNP. INCS medication has been suspected to influence the presence and thickness of microbial biofilms and inflammatory cell patterns in CRSwNP. Two series of identical nasal polyps obtained from non-allergic patients with CRSwNP (n = 56), who underwent endoscopic sinus surgery (ESS), were processed to hematoxylin-eosin (H.E.) and Gram staining, respectively. Patients were recruited into three groups. Group A (n = 21) consisted of patients with continuous preoperative INCS treatment. In group B (n = 17), patients were never treated by INCS, while in group C (n = 18) INCS medication was stopped at least 6 months before ESS. Biofilm positivity varied from 76.4 to 88.8% in different subject groups. These values and average thickness of biofilms did not reach statistically significant levels (Mann-Whitney's U probe, p > 0.05) in different patient groups. In contrast, microscopic pattern and numbers of predominant inflammatory cell populations displayed obvious differences according to INCS treatment (Mann-Whitney's U probe, p < 0.001). According to these observations, INCS treatment does not affect the presence and thickness of microbial biofilms in CRSwNP. In contrast, it has significant effects on the pattern of inflammatory cells infiltrating the subepithelial layer, which might result in beneficially altered extracellular matrix production and cytokine release.

Prospective clinical evaluation of 1.5% levofloxacin ophthalmic solution in ophthalmic perioperative disinfection.

PURPOSE: Gram-positive cocci and Propionibacterium acnes are widely reported agents of infectious postoperative endophthalmitis. This multicenter study was conducted to evaluate the eradication effectiveness and safety profile of levofloxacin 1.5% ophthalmic solution (LVFX 1.5%) for use in perioperative disinfection. METHODS: Patients who were scheduled for cataract surgery were enrolled. The perioperative regimen of LVFX 1.5% was administered 3 times daily as follows: preoperative 3 days; the day of surgery (in the morning, 1 h before surgery, and immediately after surgery); and postoperative 2 weeks. Conjunctival sac scrapings were collected 3 times in the observation period; before preoperative administration, before iodine eyewash on the day of surgery, and after completion of postoperative administration. Isolated and identified microbial strains were assessed for antibacterial susceptibility. RESULTS: One hundred patients were enrolled and data obtained from 96 patients (mean age, 72.7 ± 8.9 years). The preoperative eradication rate was 86.7% in total microbes. In the case of gram-positive cocci, the preoperative eradication rate was 100%, even though there were LVFX-registrant methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus, which had a high minimum inhibitory concentration against LVFX, such as 32 µg/mL. On the other hand, that of P. acnes was 78.3%. No acquired drug resistance was suspected in all strains. Adverse drug reactions occurred in 4.2% patients, and all were slight. CONCLUSIONS: For ophthalmic perioperative disinfection, the LVFX 1.5% ophthalmic solution showed a good safety profile, and critical eradication of gram-positive cocci, including the fluoroquinolone-resistant strains.

A retrospective non-randomized study on the impact of INTEGUSEAL, a preoperative microbial skin sealant, on the rate of surgical site infections after cardiac surgery.

OBJECTIVE: Surgical site infection (SSI) remains a serious potential complication after cardiac surgery. This study evaluated the impact of a cyanoacrylate microbial skin sealant (INTEGUSEAL) on the rate of SSI in cardiac surgery patients. METHODS: Between January 2006 and July 2008, 580 patients underwent cardiac surgery by a single surgeon (PMD). Standard preoperative skin preparation was performed in 280 patients (control group), and 300 patients (microbial skin sealant group) received microbial skin sealant in addition to standard preoperative preparation. Patient characteristics and preoperative and combined pre/intraoperative risk scores were evaluated. The primary study endpoint was freedom from SSI within 30 days. RESULTS: Both groups were established in a 15-month period. Carotid artery disease, diabetes mellitus, congestive heart failure, previous cardiac surgery, and bilateral internal mammary artery use were significantly more common in the skin sealant group. Preoperative risk scores for the development of SSI in the two groups were similar. In the skin sealant group, the combined operative risk score for SSI was significantly higher (9.8±4.0 vs. 8.7±3.7; p<0.001) nevertheless the incidence of SSI was significantly lower (2.3% vs. 6.8%; p=0.011) than in the control group. CONCLUSION: Changing a surgeon's standard preoperative practice by including a microbial skin sealant pretreatment significantly reduced the rate of SSI.

Dolosigranulum pigrum causing biomaterial-associated arthritis.

Dolosigranulum pigrum is a gram-positive, catalase-negative bacteria rarely associated with disease. We report a case of biomaterial-associated arthritis in an immunocompetent patient caused by D. pigrum. The organism was isolated from a synovial biopsy specimen and its identity confirmed by 16S rRNA gene sequencing.

Prevalence of resistance phenotypes and genotypes to macrolide, lincosamide and streptogramin antibiotics in Gram-positive cocci isolated in Tunisian Bone Marrow Transplant Center.

To investigate the prevalence of resistance to macrolide, lincosamide and streptogramin (MLS) antibiotics in Gram-positive cocci isolated in a Bone Marrow Transplant Center of Tunisia, we tested the antibiotic susceptibility of 172 clinical isolates of Staphylococcus epidermidis, Streptococcus mitis and Enterococcus faecium to macrolide erythromycin and spiramycin, the lincosamide clindamycin and the streptogramin pristinamycin. These three groups of organisms were mostly resistant to macrolides and lincosamide, but were commonly susceptible to pristinamycin. The resistance phenotypes of erythromycin-resistant isolates were determined by the five-disc test with erythromycin, spiramycin, lincomycin, clindamycin and pristinamycin, which showed that most exhibited constitutive MLS resistance. In order to determine the prevalence of the resistance genotypes and the resistance mechanisms, the prevalence of the erythromycin resistance methylase (erm) (A), erm(B), erm(C), msr(A) and macrolide efflux (mef) (A) genes in the erythromycin-resistant isolates was identified by polymerase chain reaction (PCR) analysis. The resistance was due mainly to the presence of ermB in E. faecium (80%), ermC in S. epidermidis (53%) and mefA in S. mitis (65%).

[The diagnostics and treatment of the postoperative mediastinitis].

Treatment results of 48 patients with mediastinitis after the open cardiac surgery were analyzed. The main mediastinitis risk factors were: the chronic obstructive lung desease, diabetes mekkitus, severe cardiac insufficiency, prolonged operation, the use of artificial blood circulation and sterna instsbility. Major infective agents of mediastinitis were the Gram-positive cocci. The treatment options varied from the prolonged antibiotic therapy to plastic reconstructive surgery, which were determined by the severity of mediastinitis.

SD-8, a novel therapeutic agent active against multidrug-resistant Gram positive cocci.

Anti-bacterial drug resistance is one of the most critical concerns among the scientist worldwide. The novel antimicrobial decapeptide SD-8 is designed and its minimal inhibitory concentration and therapeutic index (TI) was found in the range of 1-8 µg/ml and 45-360, respectively, against major group of Gram positive pathogens (GPP). The peptide was also found to be least hemolytic at a concentration of 180 µg/ml, i.e., nearly 77 times higher than its average effective concentration. The kinetics assay showed that the killing time is 120 min for methicillin-sensitive Staphylococcus aureus (MSSA) and 90 min for methicillin-resistant S. aureus (MRSA). Membrane permeabilization is the cause of peptide antimicrobial activity as shown by the transmission electron microscopy studies. The peptide showed the anti-inflammatory property by inhibiting COX-2 with a KD and Ki values of 2.36×10(-9) and 4.8×10(-8) M, respectively. The peptide was also found to be effective in vivo as derived from histopathological observations in a Staphylococcal skin infection rat model with MRSA as causative organism.

Antibacterial oxazolidinones: emerging structure-toxicity relationships.

The oxazolidinones are an important class of synthetic bacterial protein synthesis inhibitors with activity against Gram-positive and some fastidious Gram-negative bacteria. Key toxicological issues with the class include reversible inhibition of monoamine oxidase enzymes and reversible myelosuppression that can occur in patients treated for longer than the recommended course of therapy. Recent studies have uncovered the likely molecular mechanism underlying oxazolidinone-related myelosuppression and other toxicities, and these will be discussed here. Also reviewed are recent reports of structural modifications that can attenuate one or more of the undesired effects of oxazolidinones, while retaining the desired antibacterial effect.

Novel pharmaceutical molecules against emerging resistant gram-positive cocci

INTRODUCTION: methicillin- and also vancomycin (glycopeptide)-resistant Gram-positive organisms have emerged as an increasingly problematic cause of hospital-acquired infections, also spreading into the community. Vancomycin (glycopeptide) resistance has emerged primarily among Enterococci, but the MIC values of vancomycin for the entire Staphylococcus species are also increasing worldwide. MATERIAL AND METHODS: the aim of our review is to evaluate the efficacy and tolerability of newer antibiotics with activity against methicillin-resistant and glycopeptide-resistant Gram-positive cocci, on the ground of our experience at a tertiary care metropolitan Hospital, and the most recent literature evidences in this field. RESULTS: Quinupristin-dalfopristin, linezolid, daptomycin, and tigecycline show an excellent in vitro activity, comparable to the activity of vancomycin and teicoplanin for methicillin-resistant staphylococci, and superior to the one that vancomycin for vancomycin-resistant isolates. Dalbavancin, televancin, and oritavancin are new lipoglycopeptide agents with excellent activity against Gram-positive cocci, and have superior pharmacodynamics properties compared to vancomycin. We review the bacterial spectrum, clinical indications and practical use, pharmacologic properties, and expected adverse events and contraindications associated with each of these novel antimicrobial agents, compared with the present standard of care. DISCUSSION: linezolid activity is substantially comparable to that of vancomycin in patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia, although its penetration into the respiratory tract is exceptionally elevated. Tigecycline has activity against both Enterococus species and MRSA; it is also active against a broad spectrum of Enterobacteriaceae and anaerobes, which allows for use intraabdominal, diabetic foot and surgical infections. Daptomycin has a rapid bactericidal activity for ...