A resistência bacteriana no contexto da infecção hospitalar

Essential Oil-Based Soap with Clove and Oregano: A Promising Antifungal and Antibacterial Alternative against Multidrug-Resistant Microorganisms

The transmission of microorganisms via hands is a critical factor in healthcare-associated infections (HAIs), underscoring the importance of rigorous hand hygiene. The rise of antimicrobial-resistant microorganisms, driven in part by the overuse of antibiotics in clinical medicine, presents a significant global health challenge. Antimicrobial soaps, although commonly used, may exacerbate bacterial resistance and disrupt skin microbiota, posing additional health risks and environmental hazards. Essential oils, with their broad-spectrum antimicrobial properties, offer a promising alternative. This study evaluates the antimicrobial activity of essential oils against various bacterial and fungal strains, including multidrug-resistant isolates. Using a range of in vitro and in vivo antimicrobial assays, including minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and minimal fungicidal concentration (MFC), the essential oils were tested against a broad spectrum of pathogens. Additionally, the chemical composition of the oils was analyzed in detail using gas chromatography-mass spectrometry (CG-MS). Clove, oregano, and thyme oils demonstrated potent inhibition of all tested ATCC bacterial strains, with MIC values ranging from 3.125 to 50 μL/mL. These oils also showed significant activity against multidrug-resistant Escherichia coli and Pseudomonas aeruginosa strains. Notably, clove oil exhibited remarkable efficacy against fungal strains such as Aspergillus fumigatus and Trichophyton rubrum, with MIC values as low as 1.56 μL/mL. Synergy tests revealed that combinations of clove, oregano, and thyme oils yielded significantly lower MIC values than individual oils, indicating additive or synergistic effects. The formulation of a soap incorporating clove and oregano oils demonstrated efficacy comparable to synthetic antiseptics in vivo. These findings highlight the exceptional antimicrobial potential of essential oils, mainly clove and oregano, against resistant microorganisms, offering a viable alternative to conventional antimicrobial agents.

Epidemiological Investigation of Hospital Transmission of Corynebacterium striatum Infection by Core Genome Multilocus Sequence Typing Approach

Corynebacterium striatum has recently received increasing attention due to its multiple antimicrobial resistances and its role as an invasive infection/outbreak agent. Recently, whole-genome sequencing (WGS)-based core genome multilocus sequence typing (cgMLST) has been used in epidemiological studies of specific human pathogens. However, this method has not been reported in studies of C. striatum. In this work, we aim to propose a cgMLST scheme for C. striatum. All publicly available C. striatum genomes, 30 C. striatum strains isolated from the same hospital, and 1 epidemiologically unrelated outgroup C. striatum strain were used to establish a cgMLST scheme targeting 1,795 genes (hereinafter referred to as 1,795-cgMLST). The genotyping results of cgMLST showed good congruence with core genome-based single-nucleotide polymorphism typing in terms of tree topology. In addition, the cgMLST provided a greater discrimination than the MLST method based on 6 housekeeping genes (gyrA, gyrB, hsp65, rpoB, secA1, and sodA). We established a clonal group (CG) threshold based on 104 allelic differences; a total of 56 CGs were identified from among 263 C. striatum strains. We also defined an outbreak threshold based on seven allelic differences that is capable of identifying closely related isolates that could give clues on hospital transmission. According to the results of analysis of drug-resistant genes and virulence genes, we identified CG4, CG5, CG26, CG28, and CG55 as potentially hypervirulent and multidrug-resistant CGs of C. striatum. This study provides valuable genomic epidemiological data on the diversity, resistance, and virulence profiles of this potentially pathogenic microorganism. IMPORTANCE Recently, WGS of many human and animal pathogens has been successfully used to investigate microbial outbreaks. The cgMLST schema are powerful genotyping tools that can be used to investigate potential epidemics and provide classification of the strains precise and reliable. In this study, we proposed the development of a cgMLST typing scheme for C. striatum, and then we evaluated this scheme for its applicability to hospital transmission investigations. This report describes the first cgMLST schema for C. striatum. The analysis of hospital transmission of C. striatum based on cgMLST methods has important clinical epidemiological significance for improving nosocomial infection monitoring of C. striatum and in-depth understanding of its nosocomial transmission routes.

The Roots of Deguelia nitidula as a Natural Antibacterial Source against Staphylococcus aureus Strains

Deguelia nitidula (Benth.) A.M.G.Azevedo & R.A.Camargo (Fabaceae) is an herbaceous plant distributed in the Brazilian Amazon, and it is called "raiz do sol" (sun roots). On Marajó Island, quilombola communities use its prepared roots to treat skin diseases commonly caused by fungi, viruses, and bacteria. Thus, in this study, the extract, and its fractions from D. nitidula roots were used to perform in vitro cytotoxic and antibacterial assays against Staphylococcus aureus strains. Thereafter, liquid chromatography-mass spectrometry (LC-MS) was used for the metabolite annotation process. The ethanolic extract of D. nitidula roots show significant bactericidal activity against S. aureus with IC50 82 μg.mL-1 and a selectivity index (SI) of 21.35. Furthermore, the SREFr2 and SREFr3 fractions show a potent bactericidal activity, i.e., MIC of 46.8 μg.mL-1 for both, and MBC of 375 and 93.7 μg.mL-1, respectively. As showcased, SREFr3 shows safe and effective antibacterial activity mainly in respect to the excellent selectivity index (SI = 82.06). On the other hand, SREFr2 shows low selectivity (SI = 6.8), which characterizes it as not safe for therapeutic use. Otherwise, due to a limited amount of reference MS2 spectra in public libraries, up to now, it was not possible to perform a complete metabolite annotation. Despite that, our antibacterial results for SREFr3 and correlated substructures of amino acid derivatives show that the roots of D. nitidula are a natural source of specialized metabolites, which can be isolated in the future, and then used as a support for further bio-guided research, as well as natural drug development.

Cost-Effectiveness of Molecular Method Diagnostic for Rapid Detection of Antibiotic-Resistant Bacteria

OBJECTIVES

This study aimed to perform a cost-effectiveness analysis (CEA) of the molecular diagnostic method (MM) associated with conventional diagnostic method (CM) compared with the CM alone, for the detection of resistant profile in bacteremia, from the perspective of the Brazilian Public Health System, in intensive care units setting.

METHODS

The clinical parameters regarding methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Gram-negative bacteria (CRGNB), and vancomycin-resistant Enterococcus spp. (VRE) infections were collected from searches on PubMed, Scopus, and SciELO, using specific keywords. Data on direct medical costs to treat these infections were collected according to Brazilian Public Health System perspective from Brazilian databases, in tables of 2018 to 2019. CEA was performed after building a dynamic model, which was calibrated and validated according to international recommendations. The incremental cost-effectiveness ratio of the MM + CM compared with the CM was calculated using the outcomes "avoided death" and "avoided resistant infections." One-way sensitivity analyses were performed.

RESULTS

This CEA demonstrated that the MM + CM was dominant in all scenarios. Estimates showed that for MRSA, CRGNB, and VRE infections, every avoided death would lead to savings of Brazilian real (R$) 4.9 million ($937 301), R$2.2 million ($419 899), and R$1.3 million ($248 919), respectively. The same infections assessed by avoided resistant infections savings were projected to be R$24 964 ($4686), R$40 260 ($7558), and R$23 867 ($4480).

CONCLUSIONS

MM leads to cost reduction and increased benefits, optimizing the use of financial resources on the health system in the intensive care unit setting, in bacteremia caused by MRSA, CRGNB, and VRE.

Worldwide survey of Corynebacterium striatum increasingly associated with human invasive infections, nosocomial outbreak, and antimicrobial multidrug-resistance, 1976-2020

Corynebacterium striatum is part of microbiota of skin and nasal mucosa of humans and has been increasingly reported as the etiologic agent of community-acquired and nosocomial diseases. Antimicrobial multidrug-resistant (MDR) C. striatum strains have been increasingly related to various nosocomial diseases and/or outbreaks worldwide, including fatal invasive infections in immunosuppressed and immunocompetent patients. Although cases of infections by C. striatum still neglected in some countries, the improvement of microbiological techniques and studies led to the increase of survival of patients with C. striatum nosocomial infections at different levels of magnitude. Biofilm formation on abiotic surfaces contributes for the persistence of virulent C. striatum and dissemination of antimicrobial resistance in hospital environment. Besides that, empirical antibiotic therapy can select multi-resistant strains and transfer intra and interspecies genes horizontally. In this study, a worldwide survey of C. striatum human infections and nosocomial outbreaks was accomplished by the analysis of clinical–epidemiological and microbiological features of reported cases from varied countries, during a 44-year period (1976–2020).

Bacterial, Fungal and Viral Infections in Surgical Site: Clinical, Diagnostic and Epidemiological Aspects

AbstractSurgical Site Infections (SSI) are infections related to surgical procedures in inpatients and outpatients, indicated with high prevalence in relation to infections linked to preventable health care. Thus, the objective of the study is to perform a review on bacterial, fungal and viral infections in surgical site in relation to clinical, diagnostic and epidemiological aspects. A bibliographic and exploratory research was carried out and the Virtual Health Library (VHL), Capes Periodicals and the Pubmed to search the articles were consulted. As for the clinical aspects, the phlogistic signs that allow to identify an inflammatory picture, being a response of the organism to some aggressive agent. Among the bacterial diagnostic methods, the most used ones are the color smear examination, cultural and biochemical characteristics, ELISA, PCR and SAR. As for the detection of fungi and yeasts are the production of the germ tube, micro-culture in agar-tween 80 agar, assimilation of carbohydrates or nitrogen and fermentation of carbohydrates. For viruses, virus isolation, cell culture, laboratory animals and embryonated eggs may be used. Although bacterial infections account for most surgical infections, fungal and viral infections can also be seen in hospital settings and their diagnosis needs to be performed as soon as possible for proper treatment, reducing costs for medical services and length of stay of the patient in the hospital environment, also reducing other risks of infection.Keywords: Surgical Wound Infection. Bacterial Infections. Mycoses. Virus Diseases.ResumoAs Infecções do Sítio Cirúrgico (ISC) são infecções relacionadas a procedimentos cirúrgicos em pacientes internados e ambulatoriais, indicadas com alta prevalência em relação às infecções ligadas aos cuidados em saúde evitáveis. Neste sentido, o objetivo do estudo é realizar uma revisão sobre as infecções bacterianas, fúngicas e virais em sítio cirúrgico em relação aos aspectos clínicos, diagnósticos e epidemiológicos. Foi realizada uma pesquisa bibliográfica e exploratória e consultada a Biblioteca Virtual em Saúde (BVS), os Periódicos Capes e o Pubmed para busca dos artigos. Quanto aos aspectos clínicos, os sinais flogísticos que permitem identificar um quadro inflamatório, sendo uma resposta do organismo frente a algum agente agressor. Dentre os métodos diagnósticos bacterianos, os mais utilizados são o Exame de esfregaços corados, Características culturais e bioquímicas, ELISA, PCR e o SAR. Quanto à detecção de fungos e leveduras estão a produção do tubo germinativo, micro cultivo em ágar fubá-tween 80, assimilação de carboidratos ou de nitrogênio e fermentação dos carboidratos. Em relação aos vírus, podem ser utilizadas o isolamento dos vírus, a cultura de células, os animais de laboratório e os ovos embrionados. Apesar das infecções bacterianas representarem a maior parte das infecções cirúrgicas, as infecções fúngicas e virais também podem ser vistas em ambientes hospitalares e seu diagnóstico precisa ser realizado o mais rápido possível para um tratamento adequado, reduzindo os custos com serviços médicos e o tempo de permanência do paciente no ambiente hospitalar, diminuindo também outros riscos de infecção.Palavras-chave: Infecção da Ferida Cirúrgica. Infecções Bacterianas. Micoses. Viroses.

Human Antimicrobial Peptide Isolated From Triatoma infestans Haemolymph, Trypanosoma cruzi-Transmitting Vector

The importance of antimicrobial peptides (AMPs) in relation to the survival of invertebrates is well known. The source and the mode of action on the insects' immune system of these molecules have been described from different perspectives. Insects produce their own AMPs as well as obtain these molecules from various sources, for example by absorption through the intestinal tract, as previously described for Boophilus microplus. Blood-sucking barber bug Triatoma infestans attracts social, economic and medical interest owing to its role in the transmission of Chagas disease. Despite new studies, descriptions of AMPs from this insect have remained elusive. Thus, the aims of this work were to characterize the antimicrobial potential of human fibrinopeptide A (FbPA) obtained from the T. infestans haemolymph and identify its natural source. Therefore, FbPA was isolated from the T. infestans haemolymph through liquid chromatography and identified by mass spectrometry. This peptide exhibited antimicrobial activity against Micrococcus luteus. Native FbPA from human blood and the synthetic FbPA also exhibited antimicrobial activity. The synthetic FbPA was conjugated with fluorescein isothiocyanate and offered to the insects. The haemolymph collected after 72 h exhibited fluorescence at the same wavelength as fluorescein isothiocyanate. Our experiments show that beyond intrinsic AMP production, T. infestans is able to co-opt molecules via internalization and may use them as AMPs for protection.

CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

Objective:

To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures.

Methods:

We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study.

Results:

A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014.

Conclusion:

The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy.

STAPHYLOCOCCUS AUREUS IN NURSING PROFESSIONALS AND THE MICROORGANISM’S SUSCEPTIBILITY PROFILE TO ANTIMICROBIALS

ABSTRACT Objective: to identify the carrier’s state and the susceptibility profile of Staphylococcus aureus isolated from saliva and nasal secretion of nursing professionals to antibiotics. Method: cross-sectional study that used saliva and nasal secretion samples of 100 nursing professionals who provide care for patients with HIV/Aids. Results: forty-three percent of the participants presented positive saliva or nasal secretion samples for Staphylococcus aureus. Of the 74 nasal secretion samples with Staphylococcus aureus, 14.9% presented oxacillin resistance; 91.9% presented penicillin resistance; 44.6% presented erythromycin resistance, and 41.9% presented clindamycin resistance. Of the 12 positive saliva samples, 16.7% presented oxacillin resistance; 100.0% presented penicillin resistance; 33.4% presented erythromycin resistance, and 25.0% presented clindamycin resistance. Conclusion: nursing professionals, once aware of their carrier state of multi-resistant microorganisms, will supervise their care practices and more efficiently adopt measures for prevention and control of the epidemiological chain of these bacteria in their work environment.