Marjoram extract down-regulates the expression of Pasteurella multocida adhesion, colonization and toxin genes: A potential mechanism for its antimicrobial activity
Introduction
Pasteurella multocida (P. multocida) is an important Gram-negative pathogen associated with a spectrum of animal diseases. Strains of P. multocida are designated into 5 capsular serogroups (A, B, D, E or F) and 16 lipopolysaccharides (LPS) somatic serotypes (1–16) [1]. Certain serotypes of P. multocida can cause pasteurellosis in rabbits (snuffles) resulting in considerable economic losses in rabbit production units [2]. The outcome of infections caused by P. multocida is influenced by the complex interactions of several hosts and pathogen-specific attributes [3]. The polysaccharide capsule and LPS are of major importance as virulence factors contributed in the pathogenesis of P. multocida in the host [4]. However, many other putative virulence determinants are related to pathogenicity including fimbriae, adherence and colonization factors, iron regulating and acquisition proteins, extracellular enzymes, exotoxins and a variety of outer membrane proteins [5].
Despite using the antimicrobial therapy as the most effective tool for controlling the infectious diseases caused by P. multocida, the used antibiotic agents are failing to bring an end to many infections due to the advent of MDR pathogens, which is recognized as an alarming threat to effective treatment and prevention of bacterial infections in humans and animals [6]. Increased resistance of P. multocida isolates to tetracyclines, erythromycin, trimethoprim/sulfamethoxazole, chloramphenicol, ciprofloxacin and cefotaxime antimicrobials was previously reported with the emergence of multidrug-resistant (MDR) strains [[7], [8], [9]]. In contrary, studies in France [10], Japan [11] and Hungry [12] demonstrated that cefotaxime, ciprofloxacin, tetracyclines and chloramphenicol were active drugs against P. multocida and recommended their use in pasteurellosis treatment. The undesirable effects and the high costs of antimicrobials administration still need to be considered in control of pasteurellosis. Thus, there is a dire need for developing alternative prophylactic strategies to combat the infections caused by these resistant strains. Currently, considerable researchers have evoked rekindled attentions towards the medicinal strength of some higher plants as a reasonable source for finding novel antimicrobial compounds [13], which have resulted in the development of alternative plant-based antimicrobial drugs with least side effects as compared to commercial antibiotics.
Indeed, few studies to date have focused on the antibacterial aspects of medicinal plants against P. multocida strains that target their cellular viability [14]. However, it is not yet known whether these anti-virulence potentials could be attributed to alterations of bacterial genes` expressions. This modulation of transcription can lead to subtle changes in the physiology of bacterial cell populations with consequences for their collective behaviors and thereby controlling pasteurellosis [15]. Considering the virulence and the MDR patterns within different strains of P. multocida [6], the informed selection of the virulence factors to be targeted for prevention of the struggle with infections caused by resistant P. multocida strains becomes vital. To the best of our knowledge, there is hardly any available report on the induced expression patterns of herbal oil extracts in P. multocida.
Over the last few decades, the use of natural compounds such as medicinal plants has gained attention due to increasing concerns about the safety of synthetic chemicals and emerging antibiotic resistance in bacteria. The current in vitro study is, therefore, the first to evaluate the antimicrobial activities of five common herbal oil extracts against MDR and virulent P. multocida isolates recovered from naturally infected rabbits suffering from respiratory diseases in Egypt giving a new safe approach for its treatment as a bio-control agent. In addition, the focus of this study was targeted to estimate the impact of the effective medicinal extract at the molecular level through the application of a wide scale genomic analysis using specific real-time quantitative reverse transcription PCR (real-time qRT-PCR) assay to investigate the expression levels of five critical virulence-associated genes putatively involved in modulating the pathogenesis of P. multocida.
Section snippets
Bacterial isolates
Sixteen field bacterial isolates recovered from 200 rabbits were used in this study. They were previously isolated from clinical samples consisting of nasal swabs (3) from live rabbits with a clinical evidence of snuffles and lung tissue samples (13) those were collected from dead rabbits at different localities in Sharkia Governorate, Egypt. These isolates were definitively identified on the basis of standard laboratory findings [16]. For reliable and specific detection, the identity of P.
Characteristics of P. multocida isolates
Standard conventional laboratory tests and PCR amplification of kmt1 gene were used for confirmation of the isolates as P. multocida. In capsular PCR assays, all the isolates amplified a product of approximately 1044 bp, which is a specific product for serogroup A.
Pasteurella multocida experimental infection
Pathogenicity tests were performed for the 16 P. multocida field isolates obtained from naturally infected rabbits. After being intranasally inoculated with P. multocida isolates, 12 rabbits died within 24 h postinfection with the
Discussion
The existence of antimicrobial resistance among P. multocida isolates considers a big problem in the veterinary medical field, specifically in rabbit industry. The implication of this problem can result in increasing the treatment cost, prolongation of illness due to treatment failure and it sometimes can lead to death. In this study, efforts were exerted to find an effective and safe antimicrobial(s) from natural sources such as herbal extracts with focusing on exploring their effects on the
Conflict of interest statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed a potential conflict of interest.
Acknowledgments
The authors would like to thank Dr. Hala I Mahmoud, Animal Wealth Development Department, Faculty of Veterinary Medicine, Zagazig University, Egypt for her help in the statistical analysis of the data.
References (53)
- et al.
Virulence genes and antimicrobial susceptibility in Pasteurella multocida isolates from calves
Vet. Microbiol.
(2013) - et al.
The world of subinhibitory antibiotic concentrations
Curr. Opin. Microbiol.
(2006) - et al.
Experimental study of the pathogenicity of Pasteurella multocida capsular type B in rabbits
J. Comp. Pathol.
(2015) - et al.
Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method
Methods.
(2001) - et al.
Virulence gene profiling and antibiotic resistance pattern of Indian isolates of Pasteurella multocida of small ruminant origin
Comp. Immunol. Microbiol. Infect. Dis.
(2015) - et al.
Virulence genes and antimicrobial resistance of Pasteurella multocida isolated from poultry and swine
Braz. J. Microbiol.
(2016) - et al.
Occurrence of virulence-associated genes in Pasteurella multocida isolates obtained from different hosts
Microb. Pathog.
(2016) - et al.
Prevalence of different OmpH-types among Pasteurella multocida isolated from lungs of calves with respiratory problems
Microb. Pathog.
(2017) - et al.
Identification of Pasteurella multocida virulence genes in a septicemic mouse model using signature-tagged mutagenesis
Microb. Pathog.
(2000) - et al.
Antimicrobial resistance in bovine respiratory disease pathogens: measures, trends, and impact on efficacy
Vet. Clin. North Am. Food Anim. Pract.
(2010)
In vitro susceptibility of Pasteurella multocida subspecies multocida strains isolated from swine to 42 antimicrobial agents
Zentralbl. Bakteriol.
Synergistic effect of thymol and carvacrol combined with chelators and organic acids against Salmonella typhimurium
J. Food Prot.
Inhibition of verocytotoxigenic Escherichia coli in model broth and rumen systems by carvacrol and thymol
Int. J. Food Microbiol.
In vitro control of multiplication of some food-associated bacteria by thyme, rosemary and sage isolates
Food Control
A natural history of botanical therapeutics
Metabolism
A compendium of antibiotic-induced transcription profiles reveals broad regulation of Pasteurella multocida virulence genes
Vet. Microbiol.
Capsular serotyping of Pasteurella multocida from various animal hosts - a comparison of phenotypic and genotypic methods
Trop. Biomed.
Pasteurella: pathogenesis of bacterial infections in animals
Pathog. Bact. Infect. Anim.
Profiling of virulence associated genes of Pasteurella multocida isolated from cattle
Vet. Res. Commun.
In vitro and in vivo pathogenicity studies of Pasteurella multocida strains harbouring different ompA
Vet. Res. Commun.
Occurrence of virulence factors and antimicrobial resistance in Pasteurella multocida strains isolated from slaughter cattle in Iran
Front. Microbiol.
Virulence gene profiles of Pasteurella multocida strains isolated from cattle and buffalo
Vet. Arh.
Phenotypic characteristics of Pasteurella multocida isolated from commercial chickens affected by fowl cholera in Jos, Nigeria
Niger. J. World’s Poult. Res.
Isolation, Identification and Antibiogram of Pasteurella multocida Isolates of Rabbits sunffing from Pasterllosis
Int. J. Agro Vet. Med. Sci.
Antimicrobial susceptibility of Pasteurella multocida isolated from swine and poultry
Acta Vet. Hung.
Antimicrobial resistance in Pasteurella and Mannheimia: epidemiology and genetic basis
Vet. Res.
Cited by (26)
Insights into growth-promoting, anti-inflammatory, immunostimulant, and antibacterial activities of Toldin CRD as a novel phytobiotic in broiler chickens experimentally infected with Mycoplasma gallisepticum
2022, Poultry ScienceCitation Excerpt :Moreover, tilmicosin was superior in controlling MG infection in broiler chickens (Abd El-Hamid et al., 2019a). Recently, there is rapid development of resistant strains to the currently utilized antimicrobials (Abd El-Hamid and Bendary, 2015; Ammar et al., 2021a, 2022) due to the prolonged, excessive and uncontrolled usage of antimicrobials in humans and animals, especially in developing countries (Ammar et al., 2015, 2016a, b, 2021b, c; Abd El-Aziz et al., 2018; Abd El-Hamid et al., 2019b), which amplified the need for utilizing novel alternative antimicrobials from medicinal plants (Elmowalid et al., 2019; Ibrahim et al., 2019; Abd El-Hamid et al., 2019c) to control avian mycoplasmosis (Awad et al., 2019). Interestingly, medicinal plants such as essential oils (EOs), have antimicrobial, anti-inflammatory, and immunostimulant properties via minimizing the bacterial loads and modifying the expression of virulence and pro- and anti-inflammatory cytokines-related genes (Abd El-Hamid et al., 2021; Bendary et al., 2021).
Dietary cinnamaldehyde nanoemulsion boosts growth and transcriptomes of antioxidant and immune related genes to fight Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus)
2021, Fish and Shellfish ImmunologyCitation Excerpt :The virulence factors in S. agalactiae including CPS and those drive adhesion, colonization, invasion, immune evasion and toxicity [4] can be interfered to attenuate its pathogenicity. Recent efforts in the discovery of promising anti-virulence therapy focused on attenuation of bacterial pathogenesis by interfering with their virulence factors as new targets for attenuation [73–75]. The present study is the first proving the antipathogenic efficacy of CNE against S. agalactiae associated with fish infections.
A review on the application of herbal medicines in the disease control of aquatic animals
2020, AquacultureCitation Excerpt :Moreover, some ingredients of herbal medicine not only have antibacterial and antiviral effects, but also immune-promoting effects, which can significantly enhance the disease resistance of animals and improve their immune function (Lin and Panzer, 1994; Cutter, 2000; Alagawany et al., 2019a). Such medicines can be used to treat many viral, bacterial, and metabolic diseases that are difficult to treat using chemical drugs and antibiotics (Li and Peng, 2013; Alagawany et al., 2019b; Abd El-Hamid et al., 2019). Given the frequent occurrence of disease in the aquaculture industry and the environmental deterioration caused by the resulting treatments, the use of chemicals and antibiotics is increasingly restricted by governments and, thus, herbal feed additives have become a focus of research and development.
- 1
Both authors contributed equally to this manuscript.