Rosmarinic Acid and Sodium Citrate Have a Synergistic Bacteriostatic Effect against Vibrio Species by Inhibiting Iron Uptake

Background: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. Methods: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. Results: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe3+ to VmFbpA, the FbpA from V. metschnikovii, with apparent KD values of 8 μM vs. 17 μM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 μM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 μM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 μM, respectively. However, RA/SC does not affect the growth of Escherichia coli. Conclusions: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.

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High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Enterobacteriaceae Isolated from Gull Feces in Lisbon, Portugal

Microorganisms ◽

10.3390/microorganisms8101487 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1487

Author(s):

Marta Aires-de-Sousa ◽

Claudine Fournier ◽

Elizeth Lopes ◽

Hermínia de Lencastre ◽

Patrice Nordmann ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Bacterial Species ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Multidrug Resistant Bacteria ◽

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant ◽

Encoding Genes

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.

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Antibiotic Resistant Enterobacteriaceae in Milk Alternatives

Foods ◽

10.3390/foods10123070 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3070

Author(s):

Winnie Mukuna ◽

Abdullah Ibn Mafiz ◽

Bharat Pokharel ◽

Aniume Tobenna ◽

Agnes Kilonzo-Nthenge

Keyword(s):

Bacterial Species ◽

Antibiotic Sensitivity ◽

Enterobacter Cloacae ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Limited Data ◽

Antibiotic Resistant ◽

Predominant Species ◽

Diffusion Technique ◽

Dairy Milk

The consumption of non-dairy milk is on the rise due to health benefits. Although there is increasing inclination towards milk alternatives (MA), there is limited data on antibiotic resistant bacteria in these substitutes. The aim of this study was to investigate antimicrobial resistance of bacteria isolated from MA. A total of 138 extracts from almonds (n = 63), cashew nuts (n = 36), and soybeans (n = 39) were analyzed for Enterobacteriaceae. The identification of the bacteria was based on biochemical and PCR methods. Antibiotic sensitivity was determined by using the Kirby-Bauer disk diffusion technique. Overall, 31% (43 of 138) of extracts were positive for Enterobacteriaceae. Ten bacterial species were identified, of which Enterobacter cloacae (42.7%) and Enterobacter cancerogenus (35.4%) were the most predominant species (p < 0.05). Antibiotic resistance was exhibited to vancomycin (88.3%), novobiocin (83.8%), erythromycin (81.1%), which was significantly higher (p < 0.05) than in tetracycline (59.5%), cefpodoxime (30.6%), and nalidixic acid (6.3%). There was no resistance displayed to kanamycin and imipenem. ERY-NOV-VAN-TET and ERY-NOV-CEP-VAN-TET were the most common resistant patterns displayed by Enterobacter cloacae. The findings of this study suggest that MAs, though considered healthy, may be a reservoir of multidrug resistant opportunist pathogens.

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Prevalence of Field-Collected House Flies and Stable Flies With Bacteria Displaying Cefotaxime and Multidrug Resistance

Journal of Medical Entomology ◽

10.1093/jme/tjaa241 ◽

2020 ◽

Author(s):

Matthew T Pileggi ◽

John R Chase ◽

Runhang Shu ◽

Lin Teng ◽

Kwangcheol C Jeong ◽

...

Keyword(s):

Bacterial Species ◽

Antibiotic Use ◽

The United States ◽

Multidrug Resistant ◽

Stomoxys Calcitrans ◽

Resistant Bacteria ◽

House Flies ◽

Stable Flies ◽

Resistance Evolution ◽

High Level

Abstract Antibiotic use in livestock accounts for 80% of total antibiotic use in the United States and has been described as the driver for resistance evolution and spread. As clinical infections with multidrug-resistant pathogens are rapidly rising, there remains a missing link between agricultural antibiotic use and its impact on human health. In this study, two species of filth flies from a livestock operation were collected over the course of 11 mo: house flies Musca domestica (L.) (Diptera: Muscidae), representing a generalist feeder, and stable flies Stomoxys calcitrans (L.) (Diptera: Muscidae), representing a specialist (blood) feeder. The prevalence of flies carrying cefotaxime-resistant (CTX-R) bacteria in whole bodies and dissected guts were assayed by culturing on antibiotic-selective media, with distinct colonies identified by Sanger sequencing. Of the 149 flies processed, including 81 house flies and 68 stable flies, 18 isolates of 12 unique bacterial species resistant to high-level cefotaxime were recovered. These isolates also showed resistance to multiple classes of antibiotics. The CTX-R isolates were predominantly recovered from female flies, which bore at least two resistant bacterial species. The majority of resistant bacteria were isolated from the guts encompassing both enteric pathogens and commensals, sharing no overlap between the two fly species. Together, we conclude that house flies and stable flies in the field could harbor multidrug-resistant bacteria. The fly gut may serve as a reservoir for the acquisition and dissemination of resistance genes.

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The Role of Iron and Siderophores in Infection, and the Development of Siderophore Antibiotics

Clinical Infectious Diseases ◽

10.1093/cid/ciz825 ◽

2019 ◽

Vol 69 (Supplement_7) ◽

pp. S529-S537 ◽

Cited By ~ 21

Author(s):

Malcom G P Page

Keyword(s):

Outer Membrane ◽

Pathogenic Bacteria ◽

Phase 1 ◽

Bacterial Species ◽

Multidrug Resistant ◽

Membrane Receptors ◽

Transport Systems ◽

Resistant Bacteria

Abstract Iron is an essential nutrient for bacterial growth, replication, and metabolism. Humans store iron bound to various proteins such as hemoglobin, haptoglobin, transferrin, ferritin, and lactoferrin, limiting the availability of free iron for pathogenic bacteria. However, bacteria have developed various mechanisms to sequester or scavenge iron from the host environment. Iron can be taken up by means of active transport systems that consist of bacterial small molecule siderophores, outer membrane siderophore receptors, the TonB-ExbBD energy-transducing proteins coupling the outer and the inner membranes, and inner membrane transporters. Some bacteria also express outer membrane receptors for iron-binding proteins of the host and extract iron directly from these for uptake. Ultimately, iron is acquired and transported into the bacterial cytoplasm. The siderophores are small molecules produced and released by nearly all bacterial species and are classified according to the chemical nature of their iron-chelating group (ie, catechol, hydroxamate, α-hydroxyl-carboxylate, or mixed types). Siderophore-conjugated antibiotics that exploit such iron-transport systems are under development for the treatment of infections caused by gram-negative bacteria. Despite demonstrating high in vitro potency against pathogenic multidrug-resistant bacteria, further development of several candidates had stopped due to apparent adaptive resistance during exposure, lack of consistent in vivo efficacy, or emergence of side effects in the host. However, cefiderocol, with an optimized structure, has advanced and has been investigated in phase 1 to 3 clinical trials. This article discusses the mechanisms implicated in iron uptake and the challenges associated with the design and utilization of siderophore-mimicking antibiotics.

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Tigecycline – how powerful is it in the fight against antibiotic-resistant bacteria?

Medicina ◽

10.3390/medicina46040033 ◽

2010 ◽

Vol 46 (4) ◽

pp. 240 ◽

Cited By ~ 17

Author(s):

Vaida Šeputienė ◽

Justas Povilonis ◽

Julija Armalytė ◽

Kęstutis Sužiedėlis ◽

Alvydas Pavilonis ◽

...

Keyword(s):

Current Knowledge ◽

Bacterial Species ◽

Tetracycline Resistance ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Application Development ◽

Cellular Mechanisms ◽

Development Of Resistance ◽

Elongation Step ◽

A Site

Tigecycline is a semisynthetic analogue of earlier tetracyclines and represents the first member of a novel class of antimicrobials – glycylcyclines – recently approved for clinical use. It is active against a broad range of gram-negative and gram-positive bacterial species including clinically important multidrug-resistant nosocomial and community-acquired bacterial pathogens. The exact molecular basis of tigecycline action is not clear at present, although similarly to the tetracyclines, it has been shown to inhibit the translation elongation step by binding to the ribosome 30S subunit and preventing aminoacylated tRNAs to accommodate in the ribosomal A site. Importantly, tigecycline overcomes the action of ribosomal protection proteins and is not a substrate for tetracycline efflux pumps of most bacteria – well-known and prevalent cellular mechanisms of microbial tetracycline resistance. The present review summarizes current knowledge on the molecular mechanism of the tigecycline action, antibacterial activity against various bacteria, clinical application, development of resistance to glycylcyclines.

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Routine Intraoperative Bacterial Culture May Be Needed in Complicated Appendicitis

Annals of Coloproctology ◽

10.3393/ac.2019.11.04.1 ◽

2020 ◽

Vol 36 (3) ◽

pp. 155-162

Author(s):

Jung Tack Son ◽

Gue Chun Lee ◽

Hyung Ook Kim ◽

Taewoon Kim ◽

Donghyoun Lee ◽

...

Keyword(s):

Bacterial Species ◽

Multidrug Resistant ◽

Resistance Rate ◽

Complicated Appendicitis ◽

Resistant Bacteria ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Positive Rate ◽

Antibiotics Susceptibility ◽

Resistance Rates

Purpose: Choosing the appropriate antibiotic is important for treatment of complicated appendicitis. However, increasing multidrug resistant bacteria have been a serious problem for successful treatment. This study was designed to identify bacteria isolated from patients with complicated appendicitis and reveal their susceptibilities for antibiotics and their relationship with patient clinical course.Methods: This study included patients diagnosed with complicated appendicitis and examined the bacterial cultures and antimicrobial susceptibilities of the isolates. Data were retrospectively collected from medical records of Kangbuk Samsung Hospital from January 2008 to February 2018.Results: The common bacterial species cultured in complicated appendicitis were as follows: Escherichia coli (n=113, 48.9%), Streptococcus spp. (n=29, 12.6%), Pseudomonas spp. (n=23, 10.0%), Bacteriodes spp. (n=22, 9.5%), Klebsiella (n=11, 4.8%), and Enterococcus spp. (n=8, 3.5%). In antibiotics susceptibility testing, the positive rate of extended-spectrum beta lactamase (ESBL) was 9.1% (21 of 231). The resistance rate to carbapenem was 1.7% (4 of 231), while that to vancomycin was 0.4% (1 of 231). E. coli was 16.8% ESBL positive (19 of 113) and had 22.1% and 19.5% resistance rates to cefotaxime and ceftazidime, respectively. Inappropriate empirical antibiotic treatment (IEAT) occurred in 55 cases (31.8%) and was significantly related with organ/space surgical site infection (SSI) (7 of 55, P=0.005).Conclusion: The rate of antibiotic resistance organisms was high in community-acquired complicated appendicitis in Koreans. Additionally, IEAT in complicated appendicitis may lead to increased rates of SSI. Routine intraoperative culture in patients with complicated appendicitis may be an effective strategy for appropriate antibiotic regimen.

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Antibacterial Activities of Five Medicinal Plants in Ethiopia against Some Human and Animal Pathogens

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/2950758 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Gebremedhin Romha ◽

Birhanu Admasu ◽

Tsegaye Hiwot Gebrekidan ◽

Hailelule Aleme ◽

Gebreyohans Gebru

Keyword(s):

Medicinal Plants ◽

Bacterial Species ◽

Antibacterial Activities ◽

Multidrug Resistant ◽

Positive Control ◽

Resistant Bacteria ◽

Traditional Medicines ◽

Animal Pathogens ◽

Significant Difference

Objective. To evaluate thein vitroantibacterial activities of five plant extracts which have been used as traditional medicines by local healers against three multidrug resistant bacteria, namely,Staphylococcus aureus,Escherichia coli, andPseudomonas aeruginosa.Results. The highest mean zone of inhibition (4.66 mm) was recorded from methanol extract ofCalpurnia aurea(Ait.) Benth. at a concentration of 200 mg/ml againstS. aureus, followed byCroton macrostachyusDel. (4.43 mm) at the same dose and solvent for the same bacterial species, while methanol and chloroform extracts ofE. bruceiSchwein. did not inhibit growth of any bacterial species. The lowest value (100 μg/ml) of minimum inhibitory concentration (MIC) was observed from both methanol and chloroform extracts ofC. aurea(Ait.) Benth. against all the three bacteria. The results of the positive control had no statistically significant difference (P>0.05) when compared with crude extracts ofC. aurea(Ait.) Benth. at concentration of 200 mg/ml againstS. aureus.Conclusion. The results of the present study support the traditional uses of these medicinal plants by the local healers. ExceptErythrina bruceiSchwein., all the plants investigated in this study exhibited antibacterial activities against the test bacterial species. Further researches are needed to be conducted to evaluate efficacy of these medicinal plant species on other microbes in different agroecological settings and their safety levels as well as their phytochemical compositions.

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Molecular Mechanisms of Bacterial Resistance to Metal and Metal Oxide Nanoparticles

International Journal of Molecular Sciences ◽

10.3390/ijms20112808 ◽

2019 ◽

Vol 20 (11) ◽

pp. 2808 ◽

Cited By ~ 27

Author(s):

Nereyda Niño-Martínez ◽

Marco Felipe Salas Orozco ◽

Gabriel-Alejandro Martínez-Castañón ◽

Fernando Torres Méndez ◽

Facundo Ruiz

Keyword(s):

Metal Oxide ◽

Molecular Mechanisms ◽

Bacterial Resistance ◽

Bacterial Species ◽

Metal Oxide Nanoparticles ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Resistant Bacteria ◽

Oxide Nanoparticles ◽

Multidrug Resistant Bacteria

The increase in bacterial resistance to one or several antibiotics has become a global health problem. Recently, nanomaterials have become a tool against multidrug-resistant bacteria. The metal and metal oxide nanoparticles are one of the most studied nanomaterials against multidrug-resistant bacteria. Several in vitro studies report that metal nanoparticles have antimicrobial properties against a broad spectrum of bacterial species. However, until recently, the bacterial resistance mechanisms to the bactericidal action of the nanoparticles had not been investigated. Some of the recently reported resistance mechanisms include electrostatic repulsion, ion efflux pumps, expression of extracellular matrices, and the adaptation of biofilms and mutations. The objective of this review is to summarize the recent findings regarding the mechanisms used by bacteria to counteract the antimicrobial effects of nanoparticles.

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fosM, a new family of fosfomycin resistance gene identified in bacterial species isolated from human microbiota

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01712-20 ◽

2020 ◽

Author(s):

Sami Khabthani ◽

Mouna Hamel ◽

Sophie Alexandra Baron ◽

Seydina Diene ◽

Jean-Marc Rolain ◽

...

Keyword(s):

Resistance Genes ◽

Inhibitory Concentration ◽

Bacterial Species ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Resistance Determinants ◽

Human Microbiota ◽

New Family ◽

Fosfomycin Resistance

Fosfomycin is a decades-old antibiotic, currently reused because of its activity against multidrug resistant bacteria. Here, we used a combined in vitro/in silico approach to search for fosfomycin resistance determinants in 25 new bacterial species isolated from the human microbiota. Putative resistance genes were cloned into a susceptible Escherichia coli. Minimal Inhibitory Concentration (MIC) values increased from 1 μg/ml to 1024 μg/ml. We report here new family of potential chromosomal fosfomycin resistance genes named fosM.

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Effects of Lipidation on a Proline-Rich Antibacterial Peptide

International Journal of Molecular Sciences ◽

10.3390/ijms22157959 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7959

Author(s):

Federica Armas ◽

Adriana Di Stasi ◽

Mario Mardirossian ◽

Antonello A. Romani ◽

Monica Benincasa ◽

...

Keyword(s):

De Novo ◽

Bacterial Species ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

C Terminus ◽

Proline Rich Peptide ◽

Conventional Antibiotics

The emergence of multidrug-resistant bacteria is a worldwide health problem. Antimicrobial peptides have been recognized as potential alternatives to conventional antibiotics, but still require optimization. The proline-rich antimicrobial peptide Bac7(1-16) is active against only a limited number of Gram-negative bacteria. It kills bacteria by inhibiting protein synthesis after its internalization, which is mainly supported by the bacterial transporter SbmA. In this study, we tested two different lipidated forms of Bac7(1-16) with the aim of extending its activity against those bacterial species that lack SbmA. We linked a C12-alkyl chain or an ultrashort cationic lipopeptide Lp-I to the C-terminus of Bac7(1-16). Both the lipidated Bac-C12 and Bac-Lp-I forms acquired activity at low micromolar MIC values against several Gram-positive and Gram-negative bacteria. Moreover, unlike Bac7(1-16), Bac-C12, and Bac-Lp-I did not select resistant mutants in E. coli after 14 times of exposure to sub-MIC concentrations of the respective peptide. We demonstrated that the extended spectrum of activity and absence of de novo resistance are likely related to the acquired capability of the peptides to permeabilize cell membranes. These results indicate that C-terminal lipidation of a short proline-rich peptide profoundly alters its function and mode of action and provides useful insights into the design of novel broad-spectrum antibacterial agents.

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