scholarly journals Preventive antimicrobial action and tissue architecture ameliorations of Bacillus subtilis in challenged broilers

2021 ◽  
Vol 14 (2) ◽  
pp. 523-536
Author(s):  
Essam S. Soliman ◽  
Rania T. Hamad ◽  
Mona S. Abdallah

Background and Aim: Probiotics improve intestinal balance through bacterial antagonism and competitive exclusion. This study aimed to investigate the in vitro antimicrobial activity, as well as the in vivo preventive, immunological, productive, and histopathological modifications produced by probiotic Bacillus subtilis. Materials and Methods: The in vitro antimicrobial activities of B. subtilis (5×106 CFU/g; 0.5, 1.0*, 1.5, and 2.0 g/L) were tested against Escherichia coli O157: H7, Salmonella Typhimurium, Candida albicans, and Trichophyton mentagrophytes after exposure times of 0.25, 0.5, 1, and 2 h using minimal inhibitory concentration procedures. A total of 320 1-day-old female Ross broiler chickens were divided into five groups. Four out of the five groups were supplemented with 0.5, 1.0*, 1.5, and 2.0 g/L probiotic B. subtilis from the age of 1 day old. Supplemented 14-day-old broiler chickens were challenged with only E. coli O157: H7 (4.5×1012 CFU/mL) and S. Typhimurium (1.2×107 CFU/mL). A total of 2461 samples (256 microbial-probiotic mixtures, 315 sera, 315 duodenal swabs, and 1575 organs) were collected. Results: The in vitro results revealed highly significant (p<0.001) killing rates at all-time points in 2.0 g/L B. subtilis: 99.9%, 90.0%, 95.6%, and 98.8% against E. coli, S. Typhimurium, C. albicans, and T. mentagrophytes, respectively. Broilers supplemented with 1.5 and 2.0 g/L B. subtilis revealed highly significant increases (p<0.01) in body weights, weight gains, carcass weights, edible organs' weights, immune organs' weights, biochemical profile, and immunoglobulin concentrations, as well as highly significant declines (p<0.01) in total bacterial, Enterobacteriaceae, and Salmonella counts. Histopathological photomicrographs revealed pronounced improvements and near-normal pictures of the livers and hearts of broilers with lymphoid hyperplasia in the bursa of Fabricius, thymus, and spleen after supplementation with 2.0 g/L B. subtilis. Conclusion: The studies revealed that 1.5-2.0 g of probiotic B. subtilis at a concentration of 5×106 CFU/g/L water was able to improve performance, enhance immunity, and tissue architecture, and produce direct antimicrobial actions.

2017 ◽  
Vol 81 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Shengan Wang ◽  
Jiaying Yao ◽  
Bo Zhou ◽  
Jiaxin Yang ◽  
Maria T. Chaudry ◽  
...  

ABSTRACT Quercetin, a ubiquitous flavonoid, is known to have antibacterial effects. The purpose of this study was to investigate the effect of quercetin on cecal microbiota of Arbor Acre (AA) broiler chickens in vivo and the bacteriostatic effect and antibacterial mechanism of quercetin in vitro. In vivo, 480 AA broilers (1 day old) were randomly allotted to four treatments (negative control and 0.2, 0.4, or 0.6 g of quercetin per kg of diet) for 42 days. Cecal microbial population and distribution were measured at the end of the experiment. The cecal microflora in these broilers included Proteobacteria, Fimicutes, Bacteroidetes, and Deferribacteres. Compared with the negative control, quercetin significantly decreased the copies of Pseudomonas aeruginosa (P &lt; 0.05), Salmonella enterica serotype Typhimurium (P &lt; 0.01), Staphylococcus aureus (P &lt; 0.01), and Escherichia coli (P &lt; 0.01) but significantly increased the copies of Lactobacillus (P &lt; 0.01), Bifidobacterium (P &lt; 0.01), and total bacteria (P &lt; 0.01). In vitro, we investigated the bacteriostatic effect of quercetin on four kinds of bacteria (E. coli, P. aeruginosa, S. enterica Typhimurium, and S. aureus) and the antibacterial mechanism of quercetin in E. coli and S. aureus. The bacteriostatic effect of quercetin was stronger on gram-positive bacteria than on gram-negative bacteria. Quercetin damaged the cell walls and membranes of E. coli (at 50 × MIC) and S. aureus (at 10 × MIC). Compared with the control, the activity of the extracellular alkaline phosphatase and β-galactosidase and concentrations of soluble protein in E. coli and S. aureus were significantly increased (all P &lt; 0.01), and the activity of ATP in S. aureus was significantly increased (P &lt; 0.01); however, no significant change in ATP activity in E. coli was observed (P &gt; 0.05). These results suggest that quercetin has potential as an alternative antibiotic feed additive in animal production.


2020 ◽  
Vol 13 (2) ◽  
pp. 166-180
Author(s):  
Bashige Chiribagula V ◽  
Bakari Amuri S ◽  
Okusa Ndjolo Philippe ◽  
Kahumba Byanga J ◽  
Duez P ◽  
...  

Dialium angolense is used in Bagira for its various medicinal properties particularly in the management of infectious diseases. In this study, the methanol and aqueous extracts of leaves and fruits were evaluated for their in vitro antioxidant and antimicrobial properties and their in vivo toxicity on Cavia porcellus. The major phytochemical classes of extracts were screened using standard in-tube reactions. The antimicrobial study was tested on Candida albicans, Escherichia coli, Salmonella typhi, Staphylococcus aureus and Streptococcus pneumoniae using agar well diffusion and dilution methods, while the antioxidant activity was evaluated by a DPPH assay. For the acute toxicity study, animals (6/group) were orally given in a single dose 5000, 1000 or 15000 mg of extract/kg body weight (BW) then observed for 14 days. In sub-acute toxicity assays, 150 or 300 mg/kg BW/day were orally given, and animals observed for 28 days. Total phenolics and total flavonoids contents ranged 1.19 to 1.61 mg GAE.g-1 and 0.45 to 1.01 mg QEg-1, respectively. The extracts presented antioxidant activity with IC50 ranging 4.9 to 6.9 µg/mL. The minimal inhibitory concentration (MIC) on tested strains ranged from 1.9 to 500 µg/mL with the aqueous extract of fruits as a most active extract: MIC=1.9 µg/mL on E. coli and C. albicans. No signs of toxicity were noted during the acute and sub-acute toxicity assessments, suggesting a maximal tolerate doses (MDT) and LD50 > 15000 mg/kg BW. This study highlights the antioxidant and antimicrobial activities of Dialium angolense and suggests that further studies be directed towards the isolation of active compounds.


1970 ◽  
Vol 2 (2) ◽  
pp. 99-102 ◽  
Author(s):  
MA Rahman ◽  
MA Samad ◽  
MB Rahman ◽  
SML Kabir

Avian salmonellosis (AS), avian colibacillosis (AC) and avian pasteurellosis (AP) have been recognized as important bacterial diseases in poultry associated with morbidity and mortality in Bangladesh. The causative agents of these three diseases were isolated (5 isolates / disease) from dead chickens submitted for diagnosis at the BRAC Poultry Disease Diagnostic Centre, Gazipur during the period from January to December 2002. Five isolates of each of the Salmonella pullorum, Escherichia coli and Pasteurella multocida were evaluated against eight antibiotic containing disc which included ciprofloxacin, gentamicin, ampicillin, chloramphenicol, erythromycin, tetracycline, cephradine and penicillin G. Erythromycin in S. pullorum and Ciprofloxacin both in the E. coli and P. multocida were found highest sensitive, gentamicin, chloramphenicol, cephradine were found moderately sensitive to S. pullorum, gentamicin, tetracycline, erythromycin and ampicillin were found moderately sensitive to E. coli, and gentamicin ampicillin, cephradine and penicillin G were moderately sensitive to P. multocida. Therapeutic trials against experimentally produced S. pullorum, E. coli and P. multocida infection in three groups of broiler chickens showed that cephradine against S. pullorum and ciprofloxacin against both in E. coli and P. multocida were found highly effective both in vitro and in vivo studies, therefore, cephradine against salmonellosis and ciprofloxacin against colibacillosis and pasteurellosis are effective drugs of choice which could be used to control morbidity and mortality in poultry caused by these diseases.Key words: antibiotic sensitivity; salmonellosis; colibacillosis; pasteurellosis, broiler chickensdoi: 10.3329/bjvm.v2i2.2538Bangl. J. Vet. Med. (2004). 2 (2): 99-102


2000 ◽  
Vol 348 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Jörg P. MÜLLER ◽  
Jörg OZEGOWSKI ◽  
Stefan VETTERMANN ◽  
Jelto SWAVING ◽  
Karel H. M. VAN WELY ◽  
...  

CsaA from the Gram-positive bacterium Bacillus subtilis has been identified previously as a suppressor of the growth and protein-export defect of Escherichia coli secA(Ts) mutants. CsaA has chaperone-like activities in vivo and in vitro. To examine the role of CsaA in protein export in B. subtilis, expression of the csaA gene was repressed. While export of most proteins remained unaffected, export of at least two proteins was significantly reduced upon CsaA depletion. CsaA co-immunoprecipitates and co-purifies with the SecA proteins of E. coli and B. subtilis, and binds the B. subtilis preprotein prePhoB. Purified CsaA stimulates the translocation of prePhoB into E. coli membrane vesicles bearing the B. subtilis translocase, whereas it interferes with the SecB-mediated translocation of proOmpA into membrane vesicles of E. coli. The specific interaction with the SecA translocation ATPase and preproteins suggests that CsaA acts as a chaperone that promotes the export of a subset of preproteins in B. subtilis.


1999 ◽  
Vol 181 (7) ◽  
pp. 2118-2123 ◽  
Author(s):  
Mitsuhiro Itaya ◽  
Akira Omori ◽  
Shigenori Kanaya ◽  
Robert J. Crouch ◽  
Teruo Tanaka ◽  
...  

ABSTRACT Two genes encoding functional RNase H (EC 3.1.26.4 ) were isolated from a gram-positive bacterium, Bacillus subtilis 168. Two DNA clones exhibiting RNase H activities both in vivo and in vitro were obtained from a B. subtilis DNA library. One (28.2 kDa) revealed high similarity to Escherichia coli RNase HII, encoded by the rnhB gene. The other (33.9 kDa) was designated rnhC and encodes B. subtilisRNase HIII. The B. subtilis genome has anrnhA homologue, the product of which has not yet shown RNase H activity. Analyses of all three B. subtilis genes revealed that rnhB andrnhC cannot be simultaneously inactivated. This observation indicated that in B. subtilis both thernhB and rnhC products are involved in certain essential cellular processes that are different from those suggested by E. coli rnh mutation studies. Sequence conservation between the rnhB and rnhC genes implies that both originated from a single ancestral RNase H gene. The roles of bacterial RNase H may be indicated by the singlernhC homologue in the small genome ofMycoplasma species.


2015 ◽  
Vol 197 (11) ◽  
pp. 1952-1962 ◽  
Author(s):  
Katherine A. Black ◽  
Patricia C. Dos Santos

ABSTRACTThe 2-thiouridine (s2U) modification of the wobble position in glutamate, glutamine, and lysine tRNA molecules serves to stabilize the anticodon structure, improving ribosomal binding and overall efficiency of the translational process. Biosynthesis of s2U inEscherichia colirequires a cysteine desulfurase (IscS), a thiouridylase (MnmA), and five intermediate sulfur-relay enzymes (TusABCDE). TheE. coliMnmA adenylates and subsequently thiolates tRNA to form the s2U modification.Bacillus subtilislacks IscS and the intermediate sulfur relay proteins, yet its genome contains a cysteine desulfurase gene,yrvO, directly adjacent tomnmA. The genomic synteny ofyrvOandmnmAcombined with the absence of the Tus proteins indicated a potential functionality of these proteins in s2U formation. Here, we provide evidence that theB. subtilisYrvO and MnmA are sufficient for s2U biosynthesis. A conditionalB. subtilisknockout strain showed that s2U abundance correlates with MnmA expression, andin vivocomplementation studies inE. coliIscS- or MnmA-deficient strains revealed the competency of these proteins in s2U biosynthesis.In vitroexperiments demonstrated s2U formation by YrvO and MnmA, and kinetic analysis established a partnership between theB. subtilisproteins that is contingent upon the presence of ATP. Furthermore, we observed that the slow-growth phenotype ofE. coliΔiscSand ΔmnmAstrains associated with s2U depletion is recovered byB. subtilis yrvOandmnmA. These results support the proposal that the involvement of a devoted cysteine desulfurase, YrvO, in s2U synthesis bypasses the need for a complex biosynthetic pathway by direct sulfur transfer to MnmA.IMPORTANCEThe 2-thiouridine (s2U) modification of the wobble position in glutamate, glutamine, and lysine tRNA is conserved in all three domains of life and stabilizes the anticodon structure, thus guaranteeing fidelity in translation. The biosynthesis of s2U inEscherichia colirequires seven proteins: the cysteine desulfurase IscS, the thiouridylase MnmA, and five intermediate sulfur-relay enzymes (TusABCDE).Bacillus subtilisand most Gram-positive bacteria lack a complete set of biosynthetic components. Interestingly, themnmAcoding sequence is located adjacent toyrvO, encoding a cysteine desulfurase. In this work, we provide evidence that theB. subtilisYrvO is able to transfer sulfur directly to MnmA. Both proteins are sufficient for s2U biosynthesis in a pathway independent of the one used inE. coli.


2019 ◽  
Author(s):  
Chem Int

New copper complexes, [Cu(phen)2(Thy)]2Cl and [Cu(phen)2(Ad)]2Cl (phen = 1,10-phenantroline, Ad (Adenine, a purine nucleobase) and Thy (Thymine, a pyrimidine nucleobase)), were synthesized and characterized by atomic absorption spectroscopy (AAS), conductivity measurement, UV-visible and infrared (IR) techniques. The complexes were tested for their antimicrobial activity against two gram positive and two gram negative bacterial strains. The results of in vitro antimicrobial activities were compared with the commercially available antimicrobial agents (ciprofloxacin and chloramphenicol). This comparative study has demonstrated that [Cu(phen)2(Thy)]2Cl inhibited the growth of methicillin resistant Staphylococcus aureous (MRSA), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) better than chloramphenicol by 11.25%, 19.41% and 25.35%, respectively. It also showed better activities than ciprofloxacine on MRSA and K. pneumoniae by 2.50% and 12.13%, respectively. Similarly, [Cu(phen)2(Ad)]2Cl demonstrated better inhibitions than chloramphenicol against MRSA, E. coli and K. pneumoniae by 11.24%, 2.48% and 9.06%, respectively. Therefore, after in vivo cytotoxicity investigations, these complexes could be considered as potential antimicrobial agents.


Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 944-956 ◽  
Author(s):  
Johanna C. Karst ◽  
Anne-Emmanuelle Foucher ◽  
Tracey L. Campbell ◽  
Anne-Marie Di Guilmi ◽  
David Stroebel ◽  
...  

Characterization of ‘unknown’ proteins is one of the challenges of the post-genomic era. Here, we report a study of Bacillus subtilis YdiB, which belongs to an uncharted class of bacterial P-loop ATPases. Precise deletion of the ydiB gene yielded a mutant with much reduced growth rate compared to the wild-type strain. In vitro, purified YdiB was in equilibrium among different forms, monomers, dimers and oligomers, and this equilibrium was strongly affected by salts; high concentrations of NaCl favoured the monomeric over the oligomeric form of the enzyme. Interestingly, the ATPase activity of the monomer was about three times higher than that of the oligomer, and the monomer showed a K m of about 60 μM for ATP and a V max of about 10 nmol min−1 (mg protein)−1 (k cat ∼10 h−1). This low ATPase activity was shown to be specific to YdiB because mutation of an invariant lysine residue in the P-loop motif (K41A) strongly attenuated this rate. This mutant was unable to restore a normal growth phenotype when introduced into a conditional knockout strain for ydiB, showing that the ATPase activity of YdiB is required for the in vivo function of the protein. Oligomerization was also observed with the purified YjeE from Escherichia coli, a YdiB orthologue, suggesting that this property is shared by all members of this family of ATPases. Importantly, dimers of YdiB were also observed in a B. subtilis extract, or when stabilized by formaldehyde cross-linking for YjeE from E. coli, suggesting that oligomerization might regulate the function of this new class of proteins in vivo.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Yukun Zeng ◽  
Zuxin Gong ◽  
Binbin Wu ◽  
Wenchao Guan ◽  
Shenyi Yu ◽  
...  

Abstract Background Avian leukosis viruses (ALVs) are important contagious suppressive factors of chicken immunity and growth performance, resulted in enormous economic loss. Although virus eradication programs are applied in breeder flocks, ALVs are still widespread globally. Therefore, other valuable adjunct to reduce the negative effect of ALVs should be considered. Bursin-like peptide (BLP) showed remarkable immunomodulatory effects, whereas their influence on ALV-infected avian groups has not been reported. Here, a designed hybrid BLP was expressed in E. coli. The purified BLP was injected subcutaneously weekly in SPF chickens congenitally infected with a natural ALV strain. Then the influences of this BLP on the growth performance, immune response and virus titer of ALV-infected chickens were determined. Results This BLP injection significantly improved the body weights of ALV-infected birds (P < 0.05). BLP injection significantly enhanced organ index in the BF in ALV-infected birds (P < 0.05). The weekly injection of BLP significantly lengthened the maintenance time of antibodies against Newcastle disease virus (NDV) attenuated vaccine of ALV-infected birds (P < 0.05) and boosted the antibody titer against avian influenza virus (AIV) H5 inactive vaccine of mock chicken (P < 0.05). BLP injection in mock chickens enhanced the levels of serum cytokines (IL-2, IL-4 and interferon-γ) (P < 0.05). Surprisingly, the novel BLP significantly inhibited expression of the ALV gp85 gene in the thymus (P < 0.05), kidney (P < 0.05) and bursa of Fabricius (BF) (P < 0.01) of ALV-infected chickens. Both viral RNA copy number and protein level decreased significantly with BLP (50 μg/mL) inoculation before ALV infection in DF1 cells (P < 0.05). Conclusions This is the first report investigating the influence of BLP on the growth and immunity performance of chickens infected by ALV. It also is the first report about the antiviral effect of BLP in vivo and in vitro. This BLP expressed in E. coli showed potential as a vaccine adjuvant, growth regulator and antiretroviral drug in chickens to decrease the negative effects of ALV infection.


2016 ◽  
Vol 60 (7) ◽  
pp. 4283-4289 ◽  
Author(s):  
Bo Ma ◽  
Chao Niu ◽  
Ying Zhou ◽  
Xiaoyan Xue ◽  
Jingru Meng ◽  
...  

ABSTRACTThanatin (THA) displays potent antibiotic activity, especially against extended-spectrum-β-lactamase (ESBL)-producingEscherichia colibothin vitroandin vivo, with minimal hemolytic toxicity and satisfactory stability in plasma. However, the high cost of thanatin significantly limits its development and clinical application. To reduce the cost of peptide synthesis, a formulation of cyclic thanatin (C-thanatin) called linear thanatin (L-thanatin) was synthesized and its activity was evaluatedin vivoandin vitro. Results showed that C-thanatin and L-thanatin MICs did not differ against eight Gram-negative and two Gram-positive bacterial strains. Furthermore, the survival rates of ESBL-producing-E. coli-infected mice were consistent after C-thanatin or L-thanatin treatment at 5 or 10 mg/kg of body weight. Neither C-thanatin nor L-thanatin showed toxicity for human red blood cells (hRBCs) and human umbilical vein endothelial cells (HUVECs) at a concentration as high as 256 μg/ml. Results of circular dichroism spectroscopy indicated that the secondary structure of L-thanatin is extremely similar to that of C-thanatin. Membrane permeabilization and depolarization assays showed that C-thanatin and L-thanatin have similar abilities to permeabilize the outer and inner membranes and to induce membrane depolarization in ESBL-producingE. coli. However, neither of them caused significant HUVEC membrane permeability. These findings indicate that the two peptides have similar effects on bacterial cell membranes and that the disulfide bond in thanatin is not essential for its antimicrobial activitiesin vivoandin vitro. L-thanatin is thus a promising low-cost peptide candidate for treating ESBL-producingE. coliinfections.


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