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Enfermedades Infecciosas Y... Jan 2014
Topics: Bacteria; Drug Resistance, Bacterial; Humans; Virulence
PubMed: 24360834
DOI: 10.1016/j.eimc.2013.11.002 -
Proceedings of the National Academy of... Nov 2019
Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Bacteriophages; Gram-Negative Bacterial Infections; Humans
PubMed: 31719187
DOI: 10.1073/pnas.1917513116 -
World Journal of Microbiology &... Jun 2022Surfactin, an antibacterial lipopeptide produced by different strains of Bacillus subtilis, is a powerful biosurfactant. It also has multiple biological activities... (Review)
Review
Surfactin, an antibacterial lipopeptide produced by different strains of Bacillus subtilis, is a powerful biosurfactant. It also has multiple biological activities including antiviral, anti-mycoplasma and antiprotozoal activities, in addition to the broad-spectrum antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and fungi. Surfactin may be one of the promising alternatives to antibiotics. Surfactin's chemical structure and physicochemical properties are briefly discussed in this mini-review. Surfactin's antibacterial mechanism is mainly outlined as follows: (1) attacking pathogenic bacteria's cell membrane, causing cell membrane disintegration or osmotic pressure imbalance; (2) inhibiting pathogenic bacteria's protein synthesis, preventing cell reproduction; (3) inhibiting pathogenic bacteria's enzyme activity, affecting normal cell metabolism. This provides basis for the further research and application of surfactin. Finally, the application of surfactin in food and its prospect are summarized in brief.
Topics: Anti-Bacterial Agents; Bacillus subtilis; Gram-Negative Bacteria; Lipopeptides; Peptides, Cyclic
PubMed: 35718798
DOI: 10.1007/s11274-022-03323-3 -
Boletin Medico Del Hospital Infantil de... Mar 1993Between January to October 1991, were studied 148 samples of feces corresponding to the same number of children with acute diarrhea. In 41 (27.7%) samples, were found... (Review)
Review
Between January to October 1991, were studied 148 samples of feces corresponding to the same number of children with acute diarrhea. In 41 (27.7%) samples, were found macroscopic or microscopic blood. At least one associated bacterial pathogen capable to produce bloody diarrhea was isolated from 22 (53.7%) of these samples. Were isolated five (12.2%) Salmonella strains, all of them were S. enteritidis; nine (22.0%) Shigella: seven S. flexneri, one S. boydii, and other one S. sonnei; two (4.9%) enteroinvasive Escherichia coli strains, and six (14.6%) Campylobacter jejuni strains. A single associated invasive bacterial pathogen was isolated in 13 (31.7%) children. Mixed culture were found in nine children: five (12.2%) children had invasive pathogens association, and four (9.8%) children had invasive and no invasive pathogens association.
Topics: Diarrhea, Infantile; Escherichia coli; Female; Gastrointestinal Hemorrhage; Humans; Infant; Infant, Newborn; Male; Melena; Mexico; Prevalence; Salmonella enteritidis; Shigella
PubMed: 8442878
DOI: No ID Found -
The Pediatric Infectious Disease Journal May 2020In addition to health care settings, antibiotic resistance has also been increasing in the community. Healthy children represent an important potential reservoir of...
BACKGROUND
In addition to health care settings, antibiotic resistance has also been increasing in the community. Healthy children represent an important potential reservoir of antibiotic-resistant (AR) bacteria. However, strategies to reduce the spread of AR bacteria often fail to specifically address the factors that promote the carriage of AR bacteria in this population.The objective of this review was to Identify risk factors for carriage of AR bacteria by healthy children.
METHODS
We did a systematic search of MEDLINE, Embase and PubMed for studies in developed (OECD) countries that assessed risk factors for carriage of AR bacteria in healthy children in the community. We excluded studies done before 1998 and studies of AR Streptococcus pneumoniae carriage in the absence of pneumococcal conjugate vaccination.
RESULTS
Of 1234 studies identified, 30 were eligible for inclusion. These studies assessed the impact of 49 risk factors on AR strains of S. pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli. The majority of these risk factors were assessed in 2 or fewer studies per bacteria. Recent antibiotic consumption was associated with carriage of resistant respiratory bacteria (S. pneumoniae, H. influenzae); however, it was not consistently associated with carriage of AR bacteria in skin or stool (S. aureus and E. coli). For AR S. aureus, transmission within households appeared to have a greater impact than individual antibiotic use.
CONCLUSIONS
The factors that promote carriage of AR bacteria by healthy children differed between bacterial species. To reduce reservoirs of AR bacteria in the community, it is essential for intervention strategies to target the specific risk factors for different bacteria.
Topics: Anti-Bacterial Agents; Bacteria; Bacterial Infections; Carrier State; Child; Drug Resistance, Bacterial; Healthy Volunteers; Humans; Nasopharynx; Risk Factors
PubMed: 32301919
DOI: 10.1097/INF.0000000000002532 -
Die Naturwissenschaften Sep 2009Female houseflies, Musca domestica (Diptera: Muscidae), lay their eggs in ephemeral resources such as animal manure. Hatching larvae compete for essential nutrients with...
Female houseflies, Musca domestica (Diptera: Muscidae), lay their eggs in ephemeral resources such as animal manure. Hatching larvae compete for essential nutrients with fungi that also colonize such resources. Both the well-known antagonistic relationship between bacteria and fungi and the consistent presence of the bacterium Klebsiella oxytoca on housefly eggs led us to hypothesize (1) that K. oxytoca, and possibly other bacteria on housefly eggs, help curtail the growth of fungal resource competitors and (2) that such fungi indeed adversely affect the development of housefly larvae. Bacteria washed from housefly eggs significantly reduced the growth of fungi in chicken manure. Nineteen bacterial strains and ten fungal strains were isolated from housefly eggs or chicken manure, respectively. Co-culturing each of all the possible bacterium-fungus pairs revealed that the bacteria as a group, but no single bacterium, significantly suppressed the growth of all fungal strains tested. The bacteria's adverse effect on fungi is due to resource nutrient depletion and/or the release of antifungal chemicals. Well-established fungi in resources significantly reduced the number of larval offspring that completed development to adult flies.
Topics: Animals; Biomass; Chickens; Ergosterol; Female; Fungi; Houseflies; Klebsiella oxytoca; Larva; Manure; Ovum; Symbiosis
PubMed: 19636523
DOI: 10.1007/s00114-009-0574-1 -
Journal of Nanoscience and... Oct 2005We present a new approach for nano-object directional delivery by bacteria based upon a taxis-controlled mechanism. In this method, a stimulus is used to direct the...
We present a new approach for nano-object directional delivery by bacteria based upon a taxis-controlled mechanism. In this method, a stimulus is used to direct the bacteria's motion. When carrying nano-objects, the bacteria demonstrated the ability to deliver the "loads" to targets where the stimulus is positioned. The scheme of using taxis for targeted delivery may hold a promising future for a new route to bridge nanotechnology and biotechnology.
Topics: Chemotaxis; Drug Delivery Systems; Endocytosis; Escherichia coli; Glucose; Micromanipulation; Motion; Nanotechnology; Nanotubes
PubMed: 16245541
DOI: 10.1166/jnn.2005.168 -
Current Medical Science Feb 2018This study aimed to study whether the Sortase A (srtA) gene helps mediate coaggregation and co-adherence between Streptococcus mutans (S. mutans) and other salivary...
This study aimed to study whether the Sortase A (srtA) gene helps mediate coaggregation and co-adherence between Streptococcus mutans (S. mutans) and other salivary bacteria. S. mutans UA159 and srtA-deficient mutant served as "bait" in classical co-aggregation assays and membrane-based co-adherence assays were used to examine interactions of S. mutans with Fusobacterium nucleatum (F. nucleatum), Streptococcus mitis (S. mitis), Streptococcus gordonii (S. gordonii), Streptococcus sanguis (S. sanguis), Actinomyces naeslundii (A. naeslundii) and Lactobacillus. Co-adherence assays were also performed using unfractionated saliva from healthy individuals. Co-adhering partners of S. mutans were sensitively detected using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Both UA159 and its srtA-deficient mutant bound to F. nucleatum but not to any of the other five salivary bacteria. The srtA-deficient mutant showed lower co-adherence with F.nucleatum. The two S. mutans strains also showed similar co-adherence profiles against unfractionated salivary bacteria, except that UA159 S. mutans but not the srtA-deficient bound to a Neisseria sp. under the same conditions. Deleting srtA reduces the ability of S. mutans to bind to F.nucleatum, but it does not appear to significantly affect the binding profile of S. mutans to bulk salivary bacteria.
Topics: Aminoacyltransferases; Bacterial Adhesion; Bacterial Proteins; Cysteine Endopeptidases; Humans; Microbiota; Mutation; Saliva; Streptococcus
PubMed: 30074166
DOI: 10.1007/s11596-018-1860-y -
Respiratory Medicine Apr 2018Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections.... (Review)
Review
Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections. The most commonly encountered pathogens during this period are gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa …), but gram-positive coccus such as Staphylococcus aureus or Streptococcus pneumoniae and anaerobic bacteria can also be found. Empirical antibiotic therapy should be guided by previous colonisation of the recipient and bacterial resistance pattern in the hospital. Six months after transplantation, pneumonias are mostly due to community-acquired bacteria (S. pneumonia, H. influenza, Mycoplasma, Chlamydia and others). Opportunistic pathogens take advantage of the state of immunosuppression which is usually highest from one to six months after transplantation. During this period, but also occurring many years later in the setting of a chronically depressed immune system, bacterial pathogens with low intrinsic virulence can cause pneumonia. The diagnosis of pneumonia caused by opportunistic pathogens can be challenging. The delay in diagnosis preventing the early instauration of adequate treatment in kidney transplant recipients with a depressed immune system, frequently coupled with co-morbid conditions and a state of frailty, will affect prognosis and outcome, increasing morbidity and mortality. This review will focus on the most common opportunistic bacterial pathogens causing pneumonia in kidney transplant recipients: Legionella, Nocardia, Mycobacterium tuberculosis/nontuberculous, and Rhodococcus. Recognition of their specificities in the setting of immunosuppression will allow early diagnosis, crucial for initiation of effective therapy and successful outcome. Interactions with immunosuppressive therapy should be considered as well as reducing immunosuppression if necessary.
Topics: Aged; Anti-Bacterial Agents; Bacteria; Cross Infection; Humans; Immunosuppression Therapy; Kidney Transplantation; Legionella; Male; Middle Aged; Mycobacterium; Nocardia; Opportunistic Infections; Pneumonia, Bacterial; Prognosis; Rhodococcus; Transplant Recipients
PubMed: 29605219
DOI: 10.1016/j.rmed.2018.02.022 -
Ecotoxicology and Environmental Safety Dec 2021This work addresses the testing of two newly produced biomass carriers (micro- and nanofibers) and one commercially available AnoxKaldnes™ K3 carrier in a laboratory...
This work addresses the testing of two newly produced biomass carriers (micro- and nanofibers) and one commercially available AnoxKaldnes™ K3 carrier in a laboratory post-nitrification reactor. The carriers were prepared under parameters suitable for high-quality biomass adhesion to their surface, and each was characterized by its specific structures. As part of the evaluation of the biofilms using respirometry and molecular genetic methods, the carriers were assessed in terms of their effectiveness and comparability. The rate of biofilm development was dependent on the structure and surface properties of the individual carriers. The results showed that the biofilm most strongly adhered to nanofiber carriers, where nitrating bacteria's slower but more abundant development occurred. Microfiber carriers were more stable, but a diverse internal structure may be unsuitable in a populated carrier's early stages. The AnoxKaldnes™ K3 carriers showed the slowest growth of biofilm, but the monitored nitrifying bacteria were abundant after an extended time. AOB representatives are likely to prefer an environment with a high amount of biomass and a large active area. Conversely, NOB representatives thrive better in a slowly forming biofilm. The methods used to monitor biofilm are challenging to compare directly, but they do complement each other, which aids in verifying the individual test results. Developing new types of biomass carriers with the potential for high-quality adhesion of microorganisms is a prerequisite for the expansion of highly efficient biotechnological processes, especially for wastewater treatment.
Topics: Bacteria; Biomass; Bioreactors; Molecular Biology; Nitrification
PubMed: 34544026
DOI: 10.1016/j.ecoenv.2021.112795