The bacteria Aeromonassp. are naturally reported in aquatic ecosystems and possess pathogenic potential, being considered as emerging pathogens in humans and animals. They also cause considerable ...losses in fish farming and, through water, can contaminate numerous foods. This study quantified and analyzed the antimicrobial resistance profile of Aeromonassp. in fish. A total of 72 samples of two fish varieties (leather fish, Pseudoplatystomafasciatumx Leiariusmarmoratusand round fish, Colossomamacropomumx Piaractusmesopotamicusand Colossomamacropomumx Piaractusbrachypomus) were purchased from two types of sources (fresh and frozen) and three commercial establishments (supermarket, market, and fishmonger). The 55 isolated Aeromonascultures were evaluated for their antimicrobial resistance profile by the disc diffusion method. Upon quantification, the count of Aeromonassp. ranged from 4.22 to 6.00 Log CFU/g; ten different species, including A. eucrenophila, A. hydrophila, A. caviae, A. media, A. jandaei, A. veroniibv. sobria, A. trota, A. schubertii, A. veroniibv. veronii, and A. shigelloides, were identified. Among the 55 isolates, 64.45% showed resistance to Ampicillin-sulbactam, and 75% were sensitive to gentamicin and ciprofloxacin. It was concluded that 100% of the evaluated samples were contaminated by Aeromonassp., which may present a risk to consumer health since bacteria can be etiological agents of Foodborne Diseases. The antimicrobial resistance profile showed resistance to ampicillin and multi-resistance to different classes of antimicrobials, demonstrating problems with choosing an antimicrobial for treatment of any disease.
RESUMO: Aeromonas sp. são bactérias presentes naturalmente no ecossistema aquático e apresentam potencial patogênico, sendo considerados patógenos emergentes em humanos e animais. Ainda, causam perdas consideráveis em piscicultura e, através da água, podem também contaminar inúmeros alimentos. Diante disso o objetivo do trabalho foi quantificar e analisar o perfil de resistência aos antimicrobianos de bactérias do gênero Aeromonas sp. em peixes. Um total de 72 amostras foram adquiridas, sendo duas variedades de peixes (peixe de couro Pseudoplatystoma fasciatum x Leiarius marmoratus e os peixes redondos Colossoma macropomum x Piaractus mesopotamicus e Colossoma macropomum x Piaractus brachypomus), dois tipos (fresco e congelado) e de três estabelecimentos comerciais (supermercado, feira e peixaria). As 55 culturas isoladas de Aeromonas foram avaliadas quanto ao perfil de resistência aos antimicrobianos pelo método de difusão em disco. Os valores encontrados na quantificação de Aeromonas sp. variaram de 4,22 a 6,00 Log UFC/g, e foram identificadas dez espécies diferentes, sendo A. eucrenophila, A. hydrophila, A. caviae, A. media, A. jandaei, A. veronii bv. sobria, A. trota, A. schubertii, A. veronii bv. veronii e A. shigelloides. Entre os 55 isolados, 64,45% apresentaram resistência a Ampicilina-sulbactam, 75% foram sensíveis à gentamicina e ciprofloxacina. Concluiu-se que 100% das amostras avaliadas estavam contaminadas por Aeromonas sp. podendo apresentar risco à saúde do consumidor visto que estas podem ser agentes etiológicos de Doenças Transmitidas por Alimentos (DTAs). O perfil de resistência aos antimicrobianos comprovou a resistência a ampicilina e apresentou multirresistência a diferentes classes de antimicrobianos, demonstrando um problema relacionado à opção de antimicrobiano para tratamento no caso do desenvolvimento de alguma doença.
Actinomycetes are a group of bacteria that are widely distributed in soil, litter, water, and other natural sources. These Gram positive bacteria can produce hundreds of bioactive compounds, ...especially antibiotics. This research isolated culturable actinomycetes from mangrove sediments in the Semarang and Karimunjawa Island areas. The isolates that produce potential antibacterial compounds were identified by qualitative screening using the Biosynthetic Gene Cluster (NRPS/PKS) prediction approach. This research was conducted from June to November 2020. A total of 19 actinomycetes from Semarang and 17 actinomycetes from Karimunjawa were found to have at least one type of Biosynthetic Gene Cluster (NRPS, Type I or Type II PKS), but only three isolates had antibacterial activity against S. aureus, E. coli, and L. monocytogenes. Molecular identification found that the bacteria were similar to Brachybacterium paraconglomeratum (99.92%), Streptomyces pluripotens (100%), and Micromonospora chersina (99.08%). Results of the study concluded that the three bacterial isolates that had bacterial activity have similar genes with known antibiotic-producing genes and can potentially provide new antibiotic candidates.
Immunochromatographic Diagnosis
In article number 2310014, Chaoguang Wang, Chongwen Wang, Bing Gu, and co‐workers show that 4‐mercaptophenylboronic acid‐modified two‐dimensional film‐like magnetic ...SERS tag (GFe–DAu–D/M) exhibits universal capture ability and superior SERS activity for immunochromatographic diagnosis of three important bacteria in real clinical specimens. The GFe–DAu–D/M‐based immunochromatography method could be served as a promising candidate for application in the clinical and POCT fields for the rapid and sensitive monitoring of multiple pathogens.
Bacteria are able to sense their population's density through a cell–cell communication system, termed ‘quorum sensing’ (QS). This system regulates gene expression in response to cell density through ...the constant production and detection of signalling molecules. These molecules commonly act as auto‐inducers through the up‐regulation of their own synthesis. Many pathogenic bacteria, including those of plants, rely on this communication system for infection of their hosts. The finding that the countering of QS‐disrupting mechanisms exists in many prokaryotic and eukaryotic organisms offers a promising novel method to fight disease. During the last decade, several approaches have been proposed to disrupt QS pathways of phytopathogens, and hence to reduce their virulence. Such studies have had varied success in vivo, but most lend promising support to the idea that QS manipulation could be a potentially effective method to reduce bacterial‐mediated plant disease. This review discusses the various QS‐disrupting mechanisms found in both bacteria and plants, as well as the different approaches applied artificially to interfere with QS pathways and thus protect plant health.
In recent years, air pollution events have occurred frequently in China during the winter. Most studies have focused on the physical and chemical composition of polluted air. Some studies have ...examined the bacterial bioaerosols both indoors and outdoors. But few studies have focused on the relationship between air pollution and bacteria, especially pathogenic bacteria. Airborne PM samples with different diameters and different air quality index values were collected in Hangzhou, China from December 2014 to January 2015. High-throughput sequencing of 16S rRNA was used to categorize the airborne bacteria. Based on the NCBI database, the “Human Pathogen Database” was established, which is related to human health. Among all the PM samples, the diversity and concentration of total bacteria were lowest in the moderately or heavily polluted air. However, in the PM2.5 and PM10 samples, the relative abundances of pathogenic bacteria were highest in the heavily and moderately polluted air respectively. Considering the PM samples with different particle sizes, the diversities of total bacteria and the proportion of pathogenic bacteria in the PM10 samples were different from those in the PM2.5 and TSP samples. The composition of PM samples with different sizes range may be responsible for the variances. The relative humidity, carbon monoxide and ozone concentrations were the main factors, which affected the diversity of total bacteria and the proportion of pathogenic bacteria. Among the different environmental samples, the compositions of the total bacteria were very similar in all the airborne PM samples, but different from those in the water, surface soil, and ground dust samples. Which may be attributed to that the long-distance transport of the airflow may influence the composition of the airborne bacteria. This study of the pathogenic bacteria in airborne PM samples can provide a reference for environmental and public health researchers.
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•Total bacteria and pathogenic bacteria in airborne particulate matter were studied.•Air quality levels had a influence on total bacteria and pathogenic bacteria.•Particle sizes effected the distribution of total bacteria and pathogenic bacteria.•Relative humidity, carbon monoxide and ozone were the main factors.•The potential source environments of total bacteria were investigated.
Different concentrations and sizes of particulate matter, and various environmental factors were related to the variance of total bacteria and pathogenic bacteria.
Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common infectious bacteria in our daily life, and seriously affect human’s health. Because of the frequent and extensive ...use of antibiotics, the microbial strains forming drug resistance have become more and more difficult to deal with. Herein, we utilized bovine serum albumin (BSA) as the template to synthesize uniform copper sulfide (CuS) nanoparticles via a biomineralization method. The as-prepared BSA-CuS nanocomposites showed good biocompatibility and strong near-infrared absorbance performance and can be used as an efficient photothermal conversion agent for pathogenic bacteria ablation with a 980 nm laser at a low power density of 1.59 W/cm2. The cytotoxicity of BSA-CuS nanocomposite was investigated using skin fibroblast cells and displayed good biocompatibility. Furthermore, the antibacterial tests indicated that BSA-CuS nanocomposite showed no antibacterial activity without NIR irradiation. In contrast, they demonstrated satisfying killing bacterial ability in the presence of NIR irradiation. Interestingly, S. aureus and E. coli showed various antibacterial mechanisms, possibly because of the different architectures of bacterial walls. Considering the low cost, easy preparation, excellent biocompatibility and strong photothermal convention efficiency (24.68%), the BSA-CuS nanocomposites combined with NIR irradiation will shed bright light on the treatment of antibiotic-resistant pathogenic bacteria.
The abuse and overuse of antibiotics increased not only the exposure of aquatic animals to antibiotics but also the development of resistance in pathogenic bacteria. To investigate the effects and ...mechanisms of exposure, a long-term experiment lasting 120 days was conducted in which Xenopus tropicalis was exposed to single and combined stress factors of multiresistant pathogenic Shigella flexneri and ciprofloxacin (CIP). The intestinal oxidative stress, immune factors and flora, as well as the brain-gut axis correlation factors of X. tropicalis, were tracked to account for the response of aquatic animals to the exogenous pollutants. SOD activity and MDA content were significantly increased in stressed X. tropicalis (p < 0.001), while the levels of proinflammatory factors (IL-1β, IFN-γ) were significantly reduced (p < 0.01). The content of intestinal beneficial bacteria decreased and that of harmful bacteria increased in the intestinal flora of the stressed X. tropicalis (p < 0.001). These results suggested that S. flexneri and CIP disturbed the intestinal flora and caused oxidative damage in the host, and the body produced a series of responses, such as oxidative stress responses and regulation of the expression of immune factors, to maintain the balance of antioxidant inflammation. Significant changes in the expression of intestinal neurotransmitters (5-HT, CGRP) and brain peptides (BDNF, NCAM, NPY) (p < 0.05) also indicated that the brain-gut axis interaction was disrupted. In addition, although the coexisting CIP could reduce intestinal toxicity caused by S. flexneri, the amount of intestinal pathogenic bacteria Desulfovibrio increased significantly. Moreover, compared with the single exposure group, SOD activity, CAT activity and MDA content were significantly reduced in the dual exposure group. Therefore, the health risks of multiresistant pathogenic bacteria on the intestinal and brain-gut axis interaction should be given more attention, and the interaction of brain-gut axis is more important when antibiotics coexist.
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•S. flexneri and CIP caused oxidative damage to the X. tropicalis intestine.•The intestinal toxicity of S. flexneri decreased because of the antibacterial effect.•Exposure to S. flexneri obviously increased the amount of pathogenic Desulfovibrio.•Brain-gut axis interactions following dual exposure needs special attention.
The efficiency of current antimicrobial drugs is noticeably decreasing and thus the development of new treatments is necessary. Natural and synthetic antimicrobial peptides (AMPs) have attracted ...great attention as promising candidates. Inspired on Mo-CBP3, an antimicrobial protein from Moringa oleifera seeds, we designed and synthesized three AMPs named Mo-CBP3-PepI, Mo-CBP3-PepII, and Mo-CBP3-PepIII. All these three peptides inhibited the growth of Candida species and pathogenic bacteria, penetrate into microbial cells, but none is hemolytic or toxic to human cells. Mo-CBP3-PepIII, particularly, showed the strongest antimicrobial activity against Staphylococcus aureus and Candida species, important human pathogens. Additionally, Mo-CBP3-PepIII did not exhibit hemolytic or toxic activity to mammalian cells, but increased Staphylococcus aureus plasma membrane permeabilization. In Candida parapsilosis, Mo-CBP3-PepIII induced pore formation in the plasma membrane and overproduction of reactive oxygen species. Bioinformatics analysis suggested that Mo-CBP3-PepIII is resistant to pepsin digestion and other proteolytic enzymes present in the intestinal environment, which opens the possibility of oral delivery in future treatments. Together, these results suggest that Mo-CBP3-PepIII has great potential as an antimicrobial agent against the bacterium S. aureus and the fungi C. parapsilosis.
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•Mo-CBP3-PepI, Mo-CBP3-PepII, and Mo-CBP3-PepIII are bioinspired synthetic peptides.•Mo-CBP3-PepI, Mo-CBP3-PepII, and Mo-CBP3-PepIII have antimicrobial activity.•Mo-CBP3-PepI, Mo-CBP3-PepII, and Mo-CBP3-PepIII penetrate into microbial cells.•None of these three peptides is hemolytic or toxic to human cells.•MoCBP3-PepIII, particularly, has great potential as a future antimicrobial agent.
Introduction Pathogens causing diabetic foot infections (DFIs) vary by region globally; however, knowledge of the causative organism is essential for effective empirical treatment. We aimed to ...determine the incidence and antibiotic susceptibility of DFI pathogens worldwide, focusing on Asia and China. Methods Through a comprehensive literature search, we identified published studies on organisms isolated from DFI wounds from January 2000 to December 2020. Results Based on our inclusion criteria, we analyzed 245 studies that cumulatively reported 38,744 patients and 41,427 isolated microorganisms. DFI pathogens varied according to time and region. Over time, the incidence of Gram-positive and Gram-negative aerobic bacteria have decreased and increased, respectively. America and Asia have the highest (62.74%) and lowest (44.82%) incidence of Gram-negative bacteria, respectively. Africa has the highest incidence (26.90%) of methicillin-resistant Staphylococcus aureus. Asia has the highest incidence (49.36%) of Gram-negative aerobic bacteria with species infection rates as follows: Escherichia coli , 10.77%; Enterobacter spp. , 3.95%; and Pseudomonas aeruginosa , 11.08%, with higher local rates in China and Southeast Asia. Linezolid, vancomycin, and teicoplanin were the most active agents against Gram-positive aerobes, while imipenem and cefoperazone-sulbactam were the most active agents against Gram-negative aerobes. Discussion This systematic review showed that over 20 years, the pathogens causing DFIs varied considerably over time and region. This data may inform local clinical guidelines on empirical antibiotic therapy for DFI in China and globally. Regular large-scale epidemiological studies are necessary to identify trends in DFI pathogenic bacteria. Systematic review registration https://www.crd.york.ac.uk/prospero/ , identifier CRD42023447645.
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