Staphylococcal biofilm on the surface of catheters: electron microscopy evaluation of the inhibition of biofilm growth by RNAIII inhibiting peptide

Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host's immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.

Transitions to sustainable management of phosphorus in Brazilian agriculture.

Brazil's large land base is important for global food security but its high dependency on inorganic phosphorus (P) fertilizer for crop production (2.2 Tg rising up to 4.6 Tg in 2050) is not a sustainable use of a critical and price-volatile resource. A new strategic analysis of current and future P demand/supply concluded that the nation's secondary P resources which are produced annually (e.g. livestock manures, sugarcane processing residues) could potentially provide up to 20% of crop P demand by 2050 with further investment in P recovery technologies. However, the much larger legacy stores of secondary P in the soil (30 Tg in 2016 worth over $40 billion and rising to 105 Tg by 2050) could provide a more important buffer against future P scarcity or sudden P price fluctuations, and enable a transition to more sustainable P input strategies that could reduce current annual P surpluses by 65%. In the longer-term, farming systems in Brazil should be redesigned to operate profitably but more sustainably under lower soil P fertility thresholds.

Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm genes and biofilm formation in blood culture isolates from patients in a Brazilian teaching hospital.

Infections with coagulase-negative staphylococci are often related to biofilm formation. This study aimed to detect biofilm formation and biofilm-associated genes in blood culture isolates of Staphylococcus epidermidis and S. haemolyticus. Half (50.6%) of the 85 S. epidermidis isolates carried the icaAD genes and 15.3% the bhp gene, while these numbers were 42.9% and 0 for S. haemolyticus, respectively. According to the plate test, 30 S. epidermidis isolates were biofilm producers and 40% of them were strongly adherent, while only one (6%) of the 17 S. haemolyticus biofilm-producing isolates exhibited a strongly adherent biofilm. The concomitant presence of icaA and icaD was significantly associated with the plate and tube test results (P ≤ 0.0004). The higher frequency of icaA in S. epidermidis and of icaD in S. haemolyticus is correlated with the higher biofilm-producing capacity of the former since, in contrast to IcaD, IcaA activity is sufficient to produce small amounts of polysaccharide. Although this study emphasizes the importance of icaAD and bhp for biofilm formation in S. epidermidis, other mechanisms seem to be involved in S. haemolyticus.

Reduced susceptibility to vancomycin and biofilm formation in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures.

This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec) type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC) was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 µg mL-1, including 15.7% with an MIC of 8 µg mL-1 and 2% with an MIC of 16 µg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment.

Reduced susceptibility to vancomycin and biofilm formation in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures

This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec) type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC) was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with an MIC of 16 μg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment.

Estudo das características estomatológicas e sistêmicas em pacientes com lúpus eritematoso sistêmico / Study of characteristics and systemic stomatological in patients with lupus erythematosus

Introdução: O lúpus eritematoso sistêmico (LES) é uma doença inflamatória crônica, de causa desconhecida e de natureza autoimune. O uso de diversos medicamentos e a presença das múltiplas alterações sistêmicas podem comprometer o atendimento odontológico desses pacientes principal­ mente quando se encontram descompensados e debilitados. Objetivos: Avaliar a condição de saúde bucal e geral dos pacientes com LES, verificando: frequência e os tipos de danos sistêmicos perma­nentes e uso de medicamentos utilizados para o tratamento dessa enfermidade que comprometem o tratamento odontológico. Material e método: Foram analisados 34 pacientes portadores de LES, estes foram submetidos a uma entrevista estruturada sobre condição sistêmica e a um exame físico buco dental, avaliando: índice CPO-D, condição de saúde gengival e dor na articulação tem poro mandi­bular. Resultados: CPO-D média 15,3; Condição gengival: 65% com gengivite; artrite: 94%; envolvi­mento hematológico: 41%; envolvimento renal: 29%, envolvimento cardiovascular e pulmonar:18%. Medicamentos mais utilizados: glucocorticosteróides: 88%; anti-inflamatórios não esteróides 52%; hidroxicloroquina: 41%; antidepressivo: 32%. Conclusão: A condição de saúde bucal dos pacientes avaliados é deficiente; existe grande variabilidade de doenças sistêmicas; uso de diversos medica­mentos, com efeitos colaterais negativos e imunossupressores para a condição geral dos pacientes com LES. Esses pacientes se tornam de alto risco para o tratamento odontológico. Os Cirurgiôes-Den­tistas devem estar atentos e preparados para tratar as necessidades especiais do paciente com LES.

Introduction: Systemic lupus erythematosus (SLE) is a chronic inflammatory disease of unkno­ wn cause and autoimmune nature. The use of multiple medications and the presence of multiple systemic changes may compromise the dental care of these patients especially when they are un­ compensated and debilitated. Objectives: The aim of this study was to analyze the condition of oral and general health of patients with SLE. The frequency, types of systemic damage, use of controlled medications used to treat this disease that undertake dental treatment. Methods: 34 patients were analyzed with SLE that were submitted a structured interview about systemic condition and dental exam: DMFT index, gingival health condition and temporo mandibular joint pain. Results: DMFT average 15.3%; gingival condition: 65 % with gingivitis; arthritis: 94%; hematologic involvement: 41%, renal involvement: 29%, cardiovascular and pulmonary involvement: 18%. Most widely used drugs: glucocorticosteroids: 88%, anti - inflammatory drugs 52%; hydroxychloroquine: 410f0; an­ tidepressant: 32 Ofo. Conclusion: The oral health of the patients is poor, there is great variability in systemic diseases, use of various drugs with negative side effects and immunosuppressants for the general condition of patients with SLE. These patients becomes an high risk for dental care and the dentists may be vigilant and prepared to apply special needs of patients with SLE.

Avaliação das expectativas e sentimentos de alunos de odontologia frente ao atendimento de pacientes com necessidades especiais / Evaluation of expectations and feelings of students in dentistry to care for patients with special needs

Objetivo: Este estudo teve como objetivo avaliar o que os alunos de odontologia sentem ao atender pacien-tes com necessidades especiais, conhecer o comporta-mento do graduando diante dessas pessoas e verificar o que pode ser feito para minimizar as situações nega-tivas no atendimento desses pacientes. Métodos: Para a realização desta pesquisa foi utilizado um questionário estruturado específico, dirigido a cem graduandos, sor-teados do 3º ao 8º termo da Faculdade de Odontologia da Unoeste, que já haviam tido contato com pacientes especiais. Os alunos não precisavam se identificar no formulário. Resultados: Os sentimentos negativos mais comuns entre os alunos foram a insegurança (29%) e a dificuldade em atender o paciente (25%), e os po-sitivos, necessidade de cuidar com amor (31%) e a responsabilidade (30%). As reações comportamentais desfavoráveis mais encontradas foram o medo (36%) e a tristeza (25%), e as favoráveis foram o carinho (25%) e a proteção (25%). Para 54% dos alunos, atender esses pacientes é uma vocação; 70% dos alunos não têm cer-teza ou nunca fariam essa especialidade. Conclusão: Os sentimentos dos alunos apresentaram-se ambiva-lentes. Para minimizar as situações negativas no aten-dimento dos pacientes com necessidades especiais é