Biological properties of essential oil emphasized on the feasibility as antibiotic substitute in feedstuff

The discovery and application of antibiotics in animal feeds have boomed the development of intensive animal husbandry in the last century,until the emergence of antibiotics-resistant bacteria.To alleviate the risks aroused by antibiotics-resistant bacteria,effective antibiotic substitutes are urgently needed to replace antibiotics.Essential oils(EOs)derived from plants are illustrated as the promising antibiotic substitutes used in animal feeds,as same as their current views for poultry and livestock industries in the future.It has been widely demonstrated that the phytochemicals in EOs show multiple biofunctionability and are less likely to induce resistance in bacteria.The beneficial effects of EOs feed supplementation on the intestinal inflammation,intestinal flora,immunity,digestion,and growth performances have been already extensively examined.However,the cost-effectiveness,odor,volatility,instability and bioavailability are the challenges in effectively utilizing EOs in animal intestines.Based on previous researches,and these challenges can partially be resolved by microencapsulation and nanotechnology are promising techniques to deal with these challenges.This article presents the feasibility and foundation of EOs application as antibiotic substitutes in animal feeds,and illustrates the mechanisms,functional performances and superiority of EOs compared with antibiotics.

Neonatal Thrombocytopenia at Dakar Principal Hospital

Neonatal thrombocytopenia accounts for 20% of neonates hospitalized in the neonatal intensive care unit (NICU) at DPH. The etiologies are multiple, but bacterial infection is the third leading cause of neonatal mortality worldwide. We therefore set out to assess the frequency of neonatal thrombocytopenia associated or not with bacterial infection in the NICU. We conducted a retrospective and prospective study with the DPH NICU, over 10 months (August 2018 and April 2019). Thrombocytopenia encountered in the NICUs, were the subject of research into bacteriological, inflammatory, and epidemiological parameters using Inlog laboratory data processing software. During this period, 1280 babies were hospitalized, 94 of whom underwent thrombocytopenia, corresponding to 7.34%, with a sex ratio of 0.92. The number of babies presenting with thrombocytopenia during the first week of hospitalization was 72, accounting for 76.6%. The clinical context was usually low birth weight in 30.8% of cases and perinatal asphyxia (25%). Thrombocytopenia ranged from 2000 to 137,000 with an average of 69,520/mm3. Among these thrombocytopenias, 64 cases (68%) were below 100,000 mm3 and 44 cases had a CRP >5 mg/l. A total of 30 bacteria were isolated, including 23 Enterobacteria, 2 Streptococci, and 1 Acinetobacter. Among these enterobacteria, 14 were multidrug-resistant (MDR). Thrombocytopenia associated with a multidrug-resistant bacterial infection is a real challenging management.

Novel Mannich Bases of Benzimidazole Derivatives: An Antibacterial Study of Environmental Bacterial Strains

A previous study was conducted on the synthesis and antibacterial evaluation of Mannich bases of 2-(thioalkyl)-1H-methylbenzimidazole derivatives. The results of this study showed that certain 2-(thioalkyl)-1H-methylbenzimidazole and 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl)benzimidazole derivatives possess antibacterial activities against clinical strains, such as Escherichia coli, Klebsiella pneumonia (Gram-negative bacteria), Staphylococcus aureus and Pseudomonas aeruginosa (Gram-positive bacteria). Following these favorable results, we extended the antibacterial evaluation of this series of molecules to environmental strains. The aim of this study was to assess the impact of the methyl-piperidine group fixed at position-1 of this new series of benzimidazoles on the antibacterial activity of environmental strains. In addition, we first evaluated the antibacterial activity of four 2-(thioalkyl)methylbenzimidazole derivatives and then that of five 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl) benzimidazole derivatives. This study allowed us to show that compounds 1d and 1e could inhibit bacterial growth in vitro of the Enterobacteria P1 strain with inhibition diameters of 17.3 ± 0.6 mm and 10 ± 0.0 mm, respectively. However, addition of methyl-piperidinyl in this series showed that five (5) of 2-(thioalkyl)-methyl-1-(piperidin-1-ylmethyl) benzimidazole derivatives had an inhibitory effect on the in vitro growth of bacterial strains used except on Enterobacteria P2 with inhibition diameters between 10.0 ± 0.8 mm and 27.9 ± 1.4 mm. The introduction of the methyl-piperidinyl group at the 1-position of 2-(thioalkyl)-1H-methylbenzimidazole derivatives greatly improved the antibacterial activity against environmental bacteria such as Escherichia coli A1, A2, A3, and A4 and two Enterobacteria P1.

Dominance of Enterobacteria among Histamine-Producing Bacteria Isolated from Indian Mackerel

Histamine fish poisoning (HFP) is a major illness occurring throughout the world due to the consumption of quality of deteriorated fish containing pre-formed histamine from bacterial activities. In the study reported here, the histamine-producing bacteria were isolated from the muscle, gills and the gut of 19 samples of Indian mackerel (Rastrelliger kanagurta) from Mumbai, India. The isolates from modified Niven’s medium (MNM) were confirmed for their ability to produce histamine by using 4 different pH-indicator media, followed by HPLC analyses. Out of 202 isolates, 63 isolates produced considerable amounts of histamine on at least 3 out of 4 media used in this study. The histamine formers were identified by biochemical tests followed by sequencing of their 16SrDNA gene, which showed that 89% of the isolates belonged to 13 different genera of the family Enterobacteriaceae. The non-enterobacterial histamine-producing bacteria belonged to the genera Staphylococcus, Alkaligenes, Shewanella and Psychrobacter.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza,Ceará,Brazil

Objective:To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum(M.amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains.Methods:Strains were isolated from female M.amazonicum prawns and environmental and hatchery water.Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification,through Vitek 2 automated system and scrotyping.Susceptibility test was performed according to Clinical Laboratory Standards Institute.Results:The following genera of enlerobacteria were recovered:Enterobacter(n=11),Citrobacter(n=10),Proteus(n=2),Serratia(n=2),Kluyvera(n=2),Providencia(n=2),Cedecea(n=1),Escherichia(n=1).Edwardsiella(n=1) and BulliauxeUa(n=1).As for Vibrio,three species were identified:Vibrio cholerae non-O1/non-O139(n=4).Vibrio vulnificus(V.vulnificus)(n=1) and Vibrio mimicus(n=1).Vibrio spp.showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics,except for V.vulnificus,which presented intermediate profile to ampicillin.Conclusions:Enterobacteria do not seem to be the most important pathogens associated with M.amazonicum farming,whereas the recovery of Vibrio spp.from larviculture,with emphasis on Vibrio cholerae and V.vulnificus,deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens.Furthermore,the intermediate susceptibility of V.vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

<i>Escherichia coli</i>in seafood: A brief overview

Considering the importance of researching the bacteriological quality of seafood, the following study aimed to make a brief overview on the occurrence of Escherichia coli in marine fish and shellfish, and to discuss the sanitary importance that the isolation of this enterobacteria represents to public health.

Enterobacterial Infections Diagnosed at the Clinic of Infectious Diseases of Fann Hospital (2013-2014) Dakar, Senegal

Introduction: Entero bacteria are mainly found in the gut of man and animals. The frequent acquisition of antibiotic resistance mechanisms explains why they are the bacteria most often implicated in human infectious pathology. It is estimated to be involved in 50% of sepsis, 60% of enteritis, 70% of urinary tract infection case. Objective: To determine the prevalence of enterobacterial infections diagnosed at Fann Infectious Diseases Clinic, and describe their epidemiological, clinical, therapeutic and evolutionary aspects. Patients and Methods: This is a retrospective and descriptive study, on patients hospitalized from January 2013 to December 2014, at Fann Infectious Diseases Clinic, with bacteriological confirmation of an enterobacteria infection. Results: A total of 129 cases were collected during the study period. The average age was 41 years, and female were predominant (60%) with a sex ratio of 0.67. Comorbidity was found in 88.4% of the cases, most of which were HIV infection. The most common clinical signs were infectious syndrome (53.49%) and general impairment (40.31%). The main gateway was urinary (55.8%). Samples were monomicrobial in 76.7% of cases. Klebsiella and Escherichia were the most common and 68.7% of the subjects had probabilistic treatment. Most enterobacterial strains were resistant to third generation cephalosporins (C3G), aminoglycosides to ciprofloxacin and cotrimoxazole. Aside from 4% of them, all were sensitive to imipenem. Conclusion: The advent of antibiotics has brought hope in the treatment of enterobacterial infections. However, an increase in their resistance to the usual antibiotics has been noted in recent years. As a result, the fight against antibiotic resistance must be a priority.

Phenotypic and Genotypic Characterization of Metallo-Beta-Lactamase and Extended-Spectrum Beta-Lactamase among Enterobacteria Isolated at National Public Health Laboratory of Brazzaville

The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This work aimed to assess prevalence of beta-lactamase produced by enterobacterial isolates. Then, disc diffusion, double disc synergy test (DDST) and combined disc test (CDT) were respectively used for antimicrobial resistance, detection of Extended-Spectrum Beta-Lactamases (ESBL) and Metallo-Beta-Lactamases (MBL). bla genes were detected by PCR. A total of 132 enterobacterial strains were studied. Resistance to antibiotic families was observed with a greater frequency than 50%. Gentamicin was the least active beta-lactam antibiotic, with a resistance rate of 88%. 40.9% of strains show an ESBL phenotype and 16.6% were MBL. An overall prevalence of 74% (40/54) and respectively rates of 29.6%, 27.7% and 16.7% for blaSHV, blaCTX and blaTEM genes were observed. SHV, CTX, CTX/SHV/TEM, CTX/TEM, SHV/TEM and CTX/SHV were different ESBL genotypes observed. ESBL-producing enterobacteria isolation worried about the future of antimicrobial therapy in the Republic of Congo. This is a public health problem that requires careful monitoring and implementation of a policy of rational antibiotics use.

溶磷细菌Enterobacteria sp EnHy-401对盐渍土壤中小麦生长的影响

盆栽试验结果表明,溶磷菌Enterobacteria sp EnHy-401能较好地在盐渍土壤中定植,并对小麦的生长和矿质营养的吸收有促进作用。与对照相比,生长在经接菌处理盐渍土中的小麦,其地上部分和根系的干重增加了28.1%和14.6%,植株中对磷、钙、钾和镁的吸收率分别提高了34.4%3、6.3%、31.5%6、.3%。该菌株所表现出来的对盐渍土壤中磷素有效性的提高、对小麦吸收K+、Ca2+、Mg2+、P等矿质营养的促进作用以及小麦生长与矿质营养元素吸收之间高度的相关性表明,溶磷菌株Enterobacteria sp.EnHy-401对盐胁迫下小麦生长的促进效应主要是通过改善盐渍土中部分矿质营养的供应,增强植株对P、Ca,Mg、K等营养元素的选择性吸收而实现,该效应受到土壤盐分和营养基质的影响。

Aerobic bacteria associated with chronic suppurative otitis media in Angola

Background:Chronic suppurative otitis media(CSOM)is an important cause of hearing loss in children and constitutes a serious health problem globally with a strong association to resource-limited living conditions.Topical antibiotics combined with aural toilet is the first-hand treatment for CSOM but antimicrobial resistance and limited availability to antibiotics are obstacles in some areas.The goal of this study was to define aerobic pathogens associated with CSOM in Angola with the overall aim to provide a background for local treatment recommendations.Methods:Samples from ear discharge and the nasopharynx were collected and cultured from 152 patients with ear discharge and perforation of the tympanic membrane.Identification of bacterial species was performed with matrix-assisted laser desorption/ionization-time of flight mass spectrometry and pneumococci were serotyped using multiplex polymerase chain reactions.Antimicrobial susceptibility testing was done according to EUCAST.Results:One hundred eighty-four samples from ear discharge and 151 nasopharyngeal swabs were collected and yielded 534 and 289 individual isolates,respectively.In all patients,correspondence rate of isolates from 2 ears in patients with bilateral disease was 27.3%and 9.3%comparing isolates from the nasopharynx and ear discharge,respectively.Proteus spp.(14.7%),Pseudomonas aeruginosa(13.2%)and Enterococcus spp.(8.8%)were dominating pathogens isolated from ear discharge.A large part of the remaining species belonged to Enterobacteriaceae(23.5%).Pneumococci and Staphylococcus aureus were detected in approximately 10%of nasopharyngeal samples.Resistance rates to quinolones exceeded 10%among Enterobacteriaceae and was 30.8%in S.aureus,whereas 6.3%of P.aeruginosa were resistant.Conclusions:The infection of the middle ear in CSOM is highly polymicrobial,and isolates found in nasopharynx do not correspond well with those found in ear discharge.Pathogens associated with CSOM in Angola are dominated by gram-negatives including Enterobacteriaceae and P.aeruginosa,while gram-positive enterococci also are common.Based on the results of antimicrobial susceptibility testing topical quinolones would be the preferred antibiotic therapy of CSOM in Angola.Topical antiseptics such as aluminium acetate,acetic acid or boric acid,however,may be more feasible options due to a possibly emerging antimicrobial resistance.

Effect of broad-spectrum antibiotics on bacterial translocation in burned or septic rats

Background: Antibiotics are frequently used to treat critically ill patients, and its use is often accompanied by intestinal dysbiosis might further lead to bacterial translocation (BT). Nevertheless, studies on the relationship between antibiotic therapy and BT are rare. In the present study, we investigated the effect of broad-spectrum antibiotics on BT in an experimental rat model of burn or sepsis injury. Methods: The septic rat model was simulated by a second insult with lipopolysaccharides after burn injury. Ninety-two male Sprague-Dawley rats were randomly divided into control, burn, and sepsis groups (n = 8 or 9, each group), and the latter two groups were then treated with imipenem or ceftriaxone for 3 or 9 days. The mesenteric lymph nodes, liver, lungs, and blood were collected at each time point under sterile conditions for quantitative bacterial culture and strain identification. The differences between the groups were compared by Fisher exact test or Mann-Whitney U test. Results: Only minimal Escherichia coli translocation to the mesenteric lymph nodes was observed in the normal control group, in which the BT rate was 12.5%. Burn injury did not affect the BT rate (Burn group vs. Control group, 12.5% vs. 12.5%, P = 1.000), whereas the BT rate showed an increased trend after the second insult with lipopolysaccharide (Sepsis group us. Control group, 44.4% 12.5%, P = 0.294), and many strains of Enterobacteria spp. were detected in distant organs (liver, lung, and blood)[Sepsis group vs. Control group, 0 (0,3) us. 0 (0,0), U = 20, P = 0.045]. After the antibiotic treatment, BT to the distant organs was increased in burned rats [Burn IT3 group us. Burn group, 0 (0,2) vs. 0 (0,0);Burn IT9 group vs. Burn group, 0 (0,1) vs. 0 (0,0);Burn CT9 group Burn group, 0 (0,2) vs. 0 (0,0);all U = 20 and P = 0.076] but decreased in septic rats [Sepsis CT3 group vs. Sepsis group, 0 (0,0) vs. 0 (0,3), U = 20, P = 0.045]. The total amount of translocated bacteria, regardless of which antibiotic was used, was increased in burned rats [Burn IT9 group vs. Burn group, 2.389 (0,2.845) vs. 0 (0,2.301) Logio colony-forming units (CFU)/g, U = 14, P = 0.034;Burn CT3 group vs. Burn group, 2.602 (0,3-633) vs. 0 (0,2.301) Logio CFU/g, U = 10.5, P = 0.009], but there was a slightly decreased trend in septic rats [Sepsis IT9 group vs. Sepsis group, 2.301 (2,3-146) vs. 0 (0,4.185) Logio CFU/g, U = 36, P = 0.721;Sepsis CT9 group vs. Sepsis group, 2 (0,3.279) 0 (0,4.185) Logio CFU/g, U = 32.5, P = 0.760]. Remarkably, the quantity of Enterococci spp. dramatically increased after broad-spectrum antibiotic treatment in both the burned and septic groups [Burn IT3 group vs. Bum group, 1 (0,5.164) vs. 0 (0,0) Logio CFU/g, U = 16;Bum IT9 group vs. Burn group, 1 (0,2.845) vs. 0 (0,0) Logio CFU/g, U = 16;Bum CT3 group vs. Burn group, 2.602 (0,3-633) vs. 0 (0,0) Logio CFU/g, U = 8;Burn CT9 group vs. Bum group, 1 (0,4.326) vs. 0 (0,0) Logio CFU/g, U = 16;Sepsis IT3 group vs. Sepsis group, 2.477 (0,2.903) vs. 0 (0,0) Logio CFU/g, U = 4.5;Sepsis IT9 group us. Sepsis group, 2 (0,3.146) vs. 0 (0,0) Logio CFU/g, U = 9;Sepsis CT3 group vs. Sepsis group, 1.151 (0,2.477) vs. 0 (0,0) Logio CFU/g, U = 18;Sepsis CT9 group us. Sepsis group, 2 (0,3) us. 0 (0,0) Logio CFU/g, U = 13.5;all P < 0.05]. vs. vs. vs. Conclusions: Broad-spectrum antibiotics promote BT in burned rats but prevent BT in septic rats, especially preventing BT to distant organs, such as the liver and lung. Moreover, Enterococci spp. with high drug resistance and high pathogenicity translocated most after antibiotic treatment.

Contamination of microgreens by Salmonella enterica and Escherichia coli is influenced by selection breeding in chicory(Cichorium intybus L.)

The aim of this study was to assess whether selection breeding in chicory(Cichorium intybus L.)led changes in the susceptibility to Salmonella enterica and Escherichia coli contamination and whether the anatomical traits of the leaves are involved in the possible changes.Five chicory genotypes subjected to different intensities of selection were compared at the microgreen stage.Bacterial retention was evaluated after leaf incubation for 1.5 h on the surface of the bacterial suspension,followed by rinsing,grinding,plating on selective media,and colony forming unit(CFU)counting.The density of stomata and trichomes,total stomatal length and width,stomatal pit width,surface roughness and sharpness were evaluated.The intensively selected genotype(Witloof)was significantly more prone to contamination(2.9±0.3 lg CFU/cm^(2))as the average of the two bacterial types than the wild accession(Wild;2.3±0.4 lg CFU/cm^(2))and the moderately selected genotypes(two leaf chicories,Catalogna type,and root chicory'Magdeburg';on average,1.9±0.3 lg CFU/cm^(2)).Witloof microgreens also showed larger stomata(on average+34%for stoma width and+44%for pit width),which could justify,at least in part,the higher susceptibility to enterobacterial contamination.In fact,when contamination was performed in the dark(closed stomata),the bacterial retention in Witloof was significantly reduced in comparison with the opened stomata(-44%)and in Wild(-26%).Differences in retention between Witloof and Wild were still observed after UV treatment.The hierarchical clustering performed by grouping the leaf anatomical features was consistent with the chicory genetic groups.Our results suggest that the domestication process can affect the safety of produce and that the micromorphological traits of the leaves may be involved.

Pangenome analysis of Enterobacteria reveals richness of secondary metabolite gene clusters and their associated gene sets

In silico genome mining provides easy access to secondary metabolite biosynthetic gene clusters(BGCs)encoding the biosynthesis of many bioactive compounds,which are the basis for many important drugs used in human medicine.However,the association between BGCs and other functions encoded in the genomes of producers have remained elusive.Here,we present a systems biology workflow that integrates genome mining with a detailed pangenome analysis for detecting genes associated with a particular BGC.We analyzed 3,889 enterobacterial genomes and found 13,266 BGCs,represented by 252 distinct BGC families and 347 additional singletons.A pangenome analysis revealed 88 genes putatively associated with a specific BGC coding for the colon cancer-related colibactin that code for diverse metabolic and regulatory functions.The presented workflow opens up the possibility to discover novel secondary metabolites,better understand their physiological roles,and provides a guide to identify and analyze BGC associated gene sets.