Cleaning and disinfection programs against Campylobacter jejuni for broiler chickens: productive performance, microbiological assessment and characterization

Implementation of biosecurity measures according to legislation in intensive poultry production: An overview across 22 EU and non-EU countries

Biosecurity implementation in poultry production is essential for maintaining flock health and preventing diseases. Regulatory frameworks play a key role in standardising biosecurity practices and ensuring compliance among stakeholders. However, there is limited information on how biosecurity measures (BMs) are legally enforced across different European countries. This study aimed to identify which BMs are mandated by legislation and/or other regulatory frameworks in 22 EU and non-EU countries for intensive poultry production. Using a participatory approach involving poultry experts from these 22 countries, data collection and validation were conducted through a questionnaire covering eleven biosecurity categories and comprising 56 BMs. The survey was carried out between December 2022 and December 2023. The number of BMs mandated by legislation for all poultry species varied considerably across countries. Turkey (52), Ukraine (46), and Slovakia (38) had the highest numbers, whereas Denmark, Sweden, and Finland had none. The most regulated BMs included rodent control programs, cleaning and disinfection after each production cycle, and physical or natural farm barriers. Conversely, the least regulated BMs included farm-exclusive personnel and external silo loading, with no regulations concerning keeping other farm animals, poultry species, or pets. Broiler and layer farming were subjected to more compulsory BMs than other poultry species. Additionally, twelve countries reported BMs under other regulatory frameworks, with Serbia (55), Turkey (53), and Poland (49) having the highest numbers, while Sweden (27), Finland (26), and Norway (25) had the lowest. The most regulated BMs included designated clothing and footwear, hygiene locks, and clean house surroundings. The least regulated BMs were related to silo loading, manure collection, and a parking area outside the farm. There was considerable variation in the number and type of BMs mandated by legislation across countries, likely influenced by each country's perceived disease risk. These findings highlight the importance of establishing a harmonized biosecurity framework at the European level to address regulatory heterogeneity and enhance disease prevention in poultry production.

Using plasma-activated water for decontamination of Salmonella spp. on common building surfaces in poultry houses

Plasma-activated water (PAW) has been shown to have antimicrobial properties, making it a promising tool for surface decontamination. This study evaluated the ability of PAW generated from high voltage atmospheric cold plasma to remove Salmonella from common surfaces (stainless steel (SS), polyvinyl chloride (PVC), concrete, and wood) found in poultry houses. PAW was generated by exposing distilled water to atmospheric cold plasma in 80% humid air at 90 kV and 60 Hz for 30 min. The resulting PAW contained 1120 ppm of nitrate and 1370 ppm of hydrogen peroxide, with a pH of 1.83. PAW was then applied to coupons of SS, PVC, wood, and concrete surfaces inoculated with 7-8 log10 CFU of cocktail of Salmonella spp. (S. Typhimurium, S. Newport, S. Montevideo, and S. Enteritidis). PAW effectively reduced Salmonella levels on SS and PVC surfaces to below the detection limit within 30 s. On wood surfaces, a longer treatment time of 7.5 min was required to achieve a maximum reduction of 2.63 log10 CFU, likely due to the porosity of the wood limiting PAW contact with the bacteria. On concrete surfaces, the reduction in Salmonella levels was only 0.98 log10 CFU. This was likely due to the greater surface roughness and high alkalinity, which neutralized the PAW species.

The Global Challenge of Campylobacter: Antimicrobial Resistance and Emerging Intervention Strategies

Antimicrobial resistance (AMR) in Campylobacter species, particularly C. jejuni and C. coli, poses a significant public health threat. These bacteria, which are commonly found in livestock, poultry, companion animals, and wildlife, are the leading causes of foodborne illnesses, often transmitted through contaminated poultry. Extensive exposure to antibiotics in human and veterinary medicine creates selection pressure, driving resistance through mechanisms such as point mutations, horizontal gene transfer, and efflux pumps. Resistance to fluoroquinolones, macrolides, and tetracyclines complicates treatment and increases the risk of severe infections. Drug-resistant Campylobacter is transmitted to humans via contaminated food, water, and direct contact with animals, highlighting its zoonotic potential. Addressing this challenge requires effective interventions. Pre-harvest strategies like biosecurity and immune-based methods reduce bacterial loads on farms, while post-harvest measures, including carcass decontamination and freezing, limit contamination. Emerging approaches, such as bacteriocins and natural antimicrobials, offer chemical-free alternatives. Integrated, multidisciplinary interventions across the food chain are essential to mitigate AMR transmission and enhance food safety. Sustainable agricultural practices, antimicrobial stewardship, and innovative solutions are critical to curbing Campylobacter resistance and protecting global public health. Our review examines the dynamics of antimicrobial resistance in Campylobacter and presents current strategies to mitigate Campylobacter-related AMR, offering valuable insights for antimicrobial control in the poultry industry.

A systematic review and meta-analysis of the sources of Campylobacter in poultry production (preharvest) and their relative contributions to the microbial risk of poultry meat

A systematic review and meta-analysis were conducted to idetnify the relative contributions of the sources of Campylobacter in poultry live production to Campylobacter prevalence of broiler meat. The keywords of Campylobacter, prevalence, live production, and broiler were used in Google Scholar to address the research interest. A total of 16,800 citations were identified, and 63 relevant citations were included in the meta-analysis after applying predetermined inclusion and exclusion criteria. A generalized linear mixed model approach combined with logit transformation was used in the current meta-analysis to stabilize the variance. The analysis revealed that Campylobacter is ubiquitous in the poultry house exterior environment including surroundings, wildlife, domestic animals, and farm vehicle, with a predicted prevalence of 14%. The recovery of Campylobacter in the interior environment of the poultry house is far less abundant than in the exterior, with a prevalence of 2%, including litter, water, insects, mice, feed, and air. A lack of evidence was observed for vertical transmission due to the day-old chicks being free of Campylobacter from 4 studies identified. Live birds are the predominant carrier of Campylobacter, with a predicted prevalence of 41%. Transportation equipment used for live haul had an overall prevalence of 39%, with vehicles showing a predicted prevalence of 44% and crates with a predicted prevalence of 22%. The results of this meta-analysis highlight the need to implement effective biosecurity measures to minimize the risk of Campylobacter in poultry meat, as human activity appears to be the primary factor for Campylobacter introduction.

Biosecurity and water, sanitation, and hygiene (WASH) interventions in animal agricultural settings for reducing infection burden, antibiotic use, and antibiotic resistance: a One Health systematic review

Prevention and control of infections across the One Health spectrum is essential for improving antibiotic use and addressing the emergence and spread of antibiotic resistance. Evidence for how best to manage these risks in agricultural communities-45% of households globally-has not been systematically assembled. This systematic review identifies and summarises evidence from on-farm biosecurity and water, sanitation, and hygiene (WASH) interventions with the potential to directly or indirectly reduce infections and antibiotic resistance in animal agricultural settings. We searched 17 scientific databases (including Web of Science, PubMed, and regional databases) and grey literature from database inception to Dec 31, 2019 for articles that assessed biosecurity or WASH interventions measuring our outcomes of interest; namely, infection burden, microbial loads, antibiotic use, and antibiotic resistance in animals, humans, or the environment. Risk of bias was assessed with the Systematic Review Centre for Laboratory Animal Experimentation tool, Risk of Bias in Non-Randomized Studies of Interventions, and the Appraisal tool for Cross-Sectional Studies, although no studies were excluded as a result. Due to the heterogeneity of interventions found, we conducted a narrative synthesis. The protocol was pre-registered with PROSPERO (CRD42020162345). Of the 20 672 publications screened, 104 were included in this systematic review. 64 studies were conducted in high-income countries, 24 studies in upper-middle-income countries, 13 studies in lower-middle-income countries, two in low-income countries, and one included both upper-middle-income countries and lower-middle-income countries. 48 interventions focused on livestock (mainly pigs), 43 poultry (mainly chickens), one on livestock and poultry, and 12 on aquaculture farms. 68 of 104 interventions took place on intensive farms, 22 in experimental settings, and ten in smallholder or subsistence farms. Positive outcomes were reported for ten of 23 water studies, 17 of 35 hygiene studies, 15 of 24 sanitation studies, all three air-quality studies, and 11 of 17 other biosecurity-related interventions. In total, 18 of 26 studies reported reduced infection or diseases, 37 of 71 studies reported reduced microbial loads, four of five studies reported reduced antibiotic use, and seven of 20 studies reported reduced antibiotic resistance. Overall, risk of bias was high in 28 of 57 studies with positive interventions and 17 of 30 studies with negative or neutral interventions. Farm-management interventions successfully reduced antibiotic use by up to 57%. Manure-oriented interventions reduced antibiotic resistance genes or antibiotic-resistant bacteria in animal waste by up to 99%. This systematic review highlights the challenges of preventing and controlling infections and antimicrobial resistance, even in well resourced agricultural settings. Most of the evidence emerges from studies that focus on the farm itself, rather than targeting agricultural communities or the broader social, economic, and policy environment that could affect their outcomes. WASH and biosecurity interventions could complement each other when addressing antimicrobial resistance in the human, animal, and environmental interface.

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain-farm to fork-of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.

Situational analysis on fluoroquinolones use and characterization of high-level ciprofloxacin-resistant Enterococcus faecalis by integrated broiler operations in South Korea

Fluoroquinolones are classified as "critically important antimicrobials for human medicine"; however, their extensive use in livestock poses a significant health risk to humans as it leads to the rapid spread of antimicrobial resistance. This study confirmed that 40.0%-71.4% of the farms in three of the five integrated broiler operations were administered ciprofloxacin (CIP). Moreover, preventive purposes (60.9%), veterinarian prescriptions (82.6%), drinking water route (100%), and 1 to 3 days (82.6%) of age were significantly highest (P < 0.05). 194 high-level ciprofloxacin-resistant (HLCR) Enterococcus faecalis (E. faecalis) were found in 65 of 74 farms, and of which, the prevalence of qnrA (63.9%), tetM (60.3%), ermB (64.9%), blaz (38.7%), and catA (34.0%) was significantly highest (P < 0.05). 154 (79.4%) isolates showed MDR, and the distribution of MDR was significantly differences among the operations (P < 0.05). All HLCR E. faecalis possessed double mutations in gyrA and parC, and S83I/S80I (90.7%) mutations were most commonly identified. Interestingly, the distribution of isolates with MICs ≥ 512 for both CIP and moxifloxacin was significantly higher in CIP-administered farms (56.5%) than in non-CIP-administered farms (41.4%) (P < 0.05). Also, the prevalence of strong or moderate biofilm formers in HLCR E. faecalis was significantly higher than that of weak and no biofilm formers (P < 0.05). HLCR E. faecalis were heavily distributed in the broiler farms in Korea; therefore, it is necessary to minimize the prevalence of resistant bacteria via structural management regulations such as cleaning and disinfection of farm environments.

Drug resistance analysis of three types of avian-origin carbapenem-resistant Enterobacteriaceae in Shandong Province, China

Animal-derived Enterobacteriaceae bacteria such as Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), and Klebsiella pneumoniae (K. pneumoniae) are important food-borne zoonotic bacilli that exist widely in the broiler-breeding industry. Although carbapenem antibiotics are considered to be the last line of defense against multidrug-resistant bacteria, carbapenem-resistant Enterobacteriaceae (CRE) break through them. In our study, we therefore, examined the prevalence of CRE and characteristics of antimicrobial resistance in 6 conventional broiler-fattening farms in Shandong Province, China. Our study revealed isolation rates of 3.57% (6/168) for carbapenem-resistant E. coli, 10% (5/50) for carbapenem-resistant P. mirabilis, and 3.03% (1/33) for carbapenem-resistant K. pneumoniae. All 12 CRE bacterial strains showed varying degrees of resistance to 27 antibiotics in 8 classes and were multidrug-resistant. The rate of the strains containing bla_NDM genes, at 91.67% (11/12), was especially high. Among other results, the carrying rate of integrons in CRE bacteria was 91.67% (11/12), and 2 strains carried both class I and class II integrons, which accelerated the lateral transmission of resistant bacteria. Our first-ever finding of the 3 CRE bacteria E. coli, P. mirabilis, and K. pneumoniae on the same broiler farm suggests that poultry-derived CRE strains may pose a risk to humans. Moreover, our findings from surveillance can inform current understandings of the prevalence and characteristics of multidrug-resistant CRE in Shandong Province and, in turn, help to curb threats to food safety and public health and better prevent and control infectious zoonotic diseases.

The Use of Disinfectant in Barn Cleaning Alters Microbial Composition and Increases Carriage of Campylobacter jejuni in Broiler Chickens

To maintain food safety and flock health in broiler chicken production, biosecurity approaches to keep chicken barns free of pathogens are important. Canadian broiler chicken producers must deep clean their barns with chemical disinfectants at least once annually (full disinfection [FD]) and may wash with water (water wash [WW]) throughout the year. However, many producers use FD after each flock, assuming a greater efficacy of more stringent cleaning protocols, although little information is known regarding how these two cleaning practices affect pathogen population and gut microbiota. In the present study, a crossover experiment over four production cycles was conducted in seven commercial chicken barns to compare WW and FD. We evaluated the effects of barn cleaning methods on commercial broiler performance, cecal microbiota composition, Campylobacter and Salmonella occurrence, and Campylobacter jejuni and Clostridium perfringens abundance, as well as on short-chain fatty acid (SCFA) concentrations in the month-old broiler gut. The 30-day body weight and mortality rate were not affected by the barn cleaning methods. The WW resulted in a modest but significant effect on the structure of broiler cecal microbiota (weighted-UniFrac; adonis P = 0.05, and unweighted-UniFrac; adonis P = 0.01), with notable reductions in C. jejuni occurrence and abundance. In addition, the WW group had increased cecal acetate, butyrate, and total SCFA concentrations, which were negatively correlated with C. jejuni abundance. Our results suggest that WW may result in enhanced activity of the gut microbiota and reduced zoonotic transmission of C. jejuni in broiler production relative to FD in the absence of a disease challenge. IMPORTANCE We compared the effects of barn FD and WW methods on gut microbial community structures and pathogen prevalence of broiler chickens in a nonchallenging commercial production setting. The results revealed that barn cleaning methods had little impact on the 30-day body weight and mortality rate of broiler chickens. In addition, the FD treatment had a subtle but significant effect on the broiler cecal microbiota with increased abundances of Campylobacter and decreased SCFA concentrations, which would support the adoption of WW as a standard practice. Thus, compared to FD, WW can be beneficial to broiler chicken production by inhibiting zoonotic pathogen colonization in the chicken gut with reduced cost and labor of cleaning.

Effects of a dietary direct-fed microbial and Ferulago angulata extract on growth performance, intestinal microflora, and immune function of broiler chickens infected with Campylobacter jejuni

Colonization of the gastrointestinal tract by potentially pathogenic bacteria and their shedding in animal feces is a fundamental factor for both animal health and human food safety. This study was conducted to evaluate the efficacy of salinomycin (Sal), direct-fed microbial (DFM), and Ferulago angulata hydroalcoholic extract (FAE) against Campylobacter jejuni in broiler chickens in a 6-week pilot-scale study. A total of six hundred and seventy two 1-day-old broiler chickens were equally divided into 6 groups (each consisting of 8 replicates of 14 birds): negative control (NC; untreated and uninfected); positive control (PC; untreated, infected with C. jejuni); PC + Sal; PC + DFM; PC + 200 mg/kg of FAE (FAE200); or PC + 400 mg/kg of FAE (FAE400). All these groups (except NC) were challenged with C. jejuni on day 15. The results showed that all experimental treatments improved (P < 0.05) average daily gain compared with the PC group, and the best value was observed in the NC and FAE400 groups throughout the entire experimental period (day 1-42). The overall feed conversion ratio and mortality rate, as well as the population of C. jejuni (day 24 and 42) and Coliforms (day 42) in the ileum and cecum, were higher (P < 0.05) in broiler chickens fed with the PC diet than for chickens in the other groups, except those in the FAE200 group. Immune responses revealed that among challenged birds, those that were fed diets DFM and FAE400 had significantly higher IgG (day 24 and 42), IgA (day 24), IL-6 (day 24), and gamma interferon (day 24 and 42) concentrations than the PC group. In conclusion, dietary FAE, especially at a high level of inclusion in broiler diet (400 mg/kg), could beneficially influence the immune status, as well as improve growth performance and intestinal microflora under Campylobacter challenge, which was comparable to those of Sal and DFM supplements.

Assessment of the Effectiveness of Pre-harvest Meat Safety Interventions to Control Foodborne Pathogens in Broilers: a Systematic Review

Purpose of Review

Ensuring broilers’ meat safety is a priority to policy makers, producers, and consumers. This systematic review aims to update the recent knowledge on pre-harvest interventions to control main foodborne pathogens in broilers and to assess their effectiveness.

Recent Findings

A total of 815 studies were retrieved from PubMed® and Web of Science for 13 pathogens. In total, 51 studies regarding Campylobacter spp., Salmonella spp., VTEC, ESBL-AmpC Escherichia coli, and Clostridium perfringens were included in this review.

Summary

Research mostly focused on Salmonella spp. and Campylobacter spp. Biosecurity and management interventions had mixed outcomes, while the effectiveness of feed additives, though intensively researched, remains controversial. Research on other pathogens (i.e. ESBL-AmpC E. coli/Salmonella, and Toxoplasma gondii) was scarce, with publications focusing on epidemiology and/or on source-attribution studies. This is also true regarding research on Listeria monocytogenes, Bacillus cereus, Clostridium botulinum, Clostridium perfringens, and Staphylococcus aureus as these are frequently controlled by post-harvest interventions. Overall, studies on recent developments of novel pathogen-specific immunisation strategies are lacking.

Longitudinal monitoring of multidrug resistance in Escherichia coli on broiler chicken fattening farms in Shandong, China

The extensive use of antibiotics has, in recent years, caused antimicrobial resistance and multidrug resistance in Escherichia coli to gradually develop into a worldwide problem. These resistant E. coli could be transmitted to humans through animal products and animal feces in the environment, thereby creating a problem for bacterial treatment for humans and animals and resulting in a public health issue. Monitoring the resistance of E. coli throughout the broiler fattening period is therefore of great significance for both the poultry industry and public health. In this longitudinal study, samples were taken from 6 conventional broiler fattening farms in Shandong Province, China, at 3 different times within 1 fattening period. The overall isolation rate of E. coli was 53.04% (375/707). Antibiotic resistance was very common in the E. coli isolated from these farms, and differed for different antibiotics, with ampicillin having the highest rate (92.86%) and cefoxitin the lowest (10.12%). Multidrug resistance was as high as 91.07%. More importantly, both the resistance rate of E. coli to the different drugs and the detection rate of drug resistance genes increased over time. The mobile colistin resistance (mcr-1) gene was detected in 24.40% of the strains, and these strains often carried other drug resistance genes, such as those conferring aminoglycoside, β-lactamase, tetracycline, and sulfonamide resistance. Antimicrobial resistance and drug resistance genes in E. coli were least common in the early fattening stage. The individual detection rates of sul1, sul3, aacC4, aphA3, and mcr-1 were significantly lower (P < 0.05) for the early fattening stage than for the middle and late stages. The rational use of antibiotics, in conjunction with the improvement of the breeding environment during the entire broiler fattening cycle, will be helpful in the development of the poultry industry and the protection of public health.

Prevalence of and Risk Factors for Campylobacter spp. Colonization of Broiler Chicken Flocks in Greece

The prevalence and risk factors for Campylobacter spp. colonization of broiler flocks and broiler carcass contamination in Greek slaughterhouses were investigated. Over a 14-month period, a pool of 10 ceca and 5 neck skin samples from chicken carcasses were collected from each of 142 batches of broiler flocks slaughtered in 3 different slaughterhouses. Information on potential risk factors for Campylobacter infection in broilers was collected by an on-farm interview and linked according to the Campylobacter contamination status of broiler flocks and differences in farm characteristics and management practices identified from questionnaires. Campylobacter spp. was isolated from 73.94% and 70.42% of ceca (95% CI 65.92-80.94) and carcasses (95% CI 62.19-77.78), respectively. A significant correlation (p < 0.001) between the presence of Campylobacter spp. in broiler ceca and contamination of carcasses was found, suggesting the spread of the microorganism on the skin of carcasses during the slaughtering procedure. A multiple logistic regression showed the disinfection of the poultry house being conducted by unskilled personnel (odds ratio [OR] ¼ = 3.983) as a significant risk factor (p < 0.05) and the use of straw litter as bedding material (OR ¼ = 0.170) and closure of windows during the intervals of production cycles (OR ¼ = 0.396) as significant protective factors (p < 0.05) for broiler flock contamination. These results are important and help further the understanding of the epidemiology of Campylobacter spp. derived from poultry in Greece.

Effect of probiotic preparations (EM) on productive characteristics, carcass composition, and microbial contamination in a commercial broiler chicken farm

This experiment evaluated the effect of Pro-Biotyk (Em-15) and EMFarma™ probiotics on body weight, feed intake and conversion, carcass traits, and microbial contamination in a poultry house. The probiotic preparations caused a nonsignificant increase in body weight (42 days), feed intake, and feed conversion ratio (1-42 days) and a nonsignificant decrease in chicken mortality from 4 weeks of rearing. Chickens exposed to probiotics did not differ significantly in preslaughter body weight, carcass weight, dressing percentage, and the content of carcass components. The carcasses from experimental chickens had a lower percentage of breast muscle, leg muscle, abdominal fat, and neck, as well as a higher percentage of skin with subcutaneous fat, wings, and remainder of carcasses compared with the carcasses from control birds. The probiotic preparations used in this study were highly effective as auxiliary disinfectants.

Characterization and Phylogenetic Analysis of Campylobacter Species Isolated from Paediatric Stool and Water Samples in the Northwest Province, South Africa

Antibiotic-resistant Campylobacter could adversely affect treatment outcomes, especially in children. We investigated the antibiotic susceptibility profiles, virulence potentials and genetic relatedness of Campylobacter spp. from paediatric and water samples in the North West Province, South Africa. Overall, 237 human and 20 water isolates were identified using culture and real-time polymerase chain reaction (PCR). The antibiotic susceptibility profiles were determined using the disk diffusion method. Gradient strips were used to determine the minimum inhibitory concentration of each antibiotic. Antibiotic resistance (gryA, tetO and 23S rRNA 2075G and 2074C) and virulence (cadF and ciaB) genes were also investigated using PCR. A phylogenetic tree to ascertain the clonality between water and clinical isolates was constructed using MEGA 7. Overall, 95% (water) and 64.7% (human) of the isolates were resistant to at least one antibiotic tested. The highest resistance was against clarithromycin (95%) for water and ampicillin (60.7%) for human isolates. The 23S rRNA 2075G/2074C mutation was the most expressed resistance gene. Phylogenetic reconstruction revealed eight intermixed clades within water and human Campylobacter isolates. This study suggests the possible circulation of potentially pathogenic antibiotic-resistant Campylobacter in the Northwest Province, South Africa with drinking water being a possible vector for disease transmission in this area.

Formaldehydes in Feed and Their Potential Interaction With the Poultry Gastrointestinal Tract Microbial Community-A Review

As antibiotics continue to be phased out of livestock production, alternative feed amendments have received increased interest not only from a research standpoint but for commercial application. Most of the emphasis to date has focused on food safety aspects, particularly on lowering the incidence of foodborne pathogens in livestock. Several candidates are currently either being examined or are already being implemented in commercial settings. Among these candidates are chemical compounds such as formaldehyde. Formaldehyde has historically been used to inhibit Salmonella in feeds during feed processing. Currently, there are several commercial products available for this purpose. This review will cover both the historical background, current research, and prospects for further research on the poultry gastrointestinal tract and feeds treated with formaldehyde.

Field Interventions Against Colonization of Broilers by Campylobacter

Poultry accounts for a high proportion of human campylobacteriosis cases, and the problem of Campylobacter colonization of broiler flocks has proven to be intractable. Owing to their broad host range and genetic instability, Campylobacter organisms are ubiquitous and adaptable in the broiler farm environment, colonizing birds heavily and spreading rapidly after introduction into a flock. This review examines strategies to prevent or suppress such colonization, with a heavy emphasis on field investigations. Attempts to exclude Campylobacter via enhanced biosecurity and hygiene measures have met with mixed success. Reasons for this are becoming better understood as investigations focus on houses, ventilation, biosecurity practices, external operators, and compliance, among other factors. It is evident that piecemeal approaches are likely to fail. Complementary measures include feed and drinking water treatments applied in either preventive or suppressive modes using agents including organic acids and their derivatives, also litter treatments, probiotics, prebiotics, and alterations to diet. Some treatments aim to reduce the number of Campylobacter organisms entering abattoirs by suppressing intestinal colonization just before slaughter; these include acid water treatment or administration of bacteriophages or bacteriocins. Experimental vaccines historically have had little success, but some recent subunit vaccines show promise. Overall, there is wide variation in the control achieved, and consistency and harmonization of trials is needed to enable robust evaluation. There is also some potential to breed for resistance to Campylobacter. Good and consistent control of flock colonization by Campylobacter may require an as-yet undetermined combination of excellent biosecurity plus complementary measures.

Effect of Different Disinfectants on Bacterial Aerosol Diversity in Poultry Houses

To better understand the effect of different disinfectants on the types and quantities of microorganisms in a broiler chicken house, five different types of disinfectants, including ozone, available chlorine, quaternary ammonium salt, glutaraldehyde, and mixed disinfectant, were used. The broiler house microbial communities were analyzed by high-throughput sequencing combined with air sampling. The results showed that the concentrations of airborne aerobic bacteria in the empty broiler houses after application of different disinfectants were significantly reduced compared to a house untreated with disinfectant (P < 0.05 or P < 0.01), and the number of inhalable particles of airborne aerobic bacteria sharply decreased after disinfection. Of the five disinfectants, the mixed disinfectant had the best disinfection efficacy on the total microbial communities (P < 0.05). A total of 508,143 high-quality sequences were obtained by high-throughput sequencing, which identified 1995 operational taxonomic units. In total, 42 phyla and 312 genera were identified. The structures of airborne microbial communities in the broiler houses after the different disinfectants were applied differed. In the house treated with the mixed disinfectant, the microbial communities containing opportunistic pathogens, such as Escherichia-Shigella, Bacillus, and Pseudomonas, had the lowest abundance, with a significant decrease compared to the house untreated with disinfectant. The alpha diversity index showed low diversity of the microbial communities in the house treated with mixed disinfectant. In contrast to the other four disinfectants, only a small amount of bacteria was detected in the air sample in the house treated with the mixed disinfectant; specifically, only four phyla were found (Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes). The mixed disinfectant produced a positive effect on disinfection for four phyla; however, it didn’t thoroughly eliminate them. At genus level, Bacillus, Arenimonas, and Shinella could not be detected in the house treated with the mixed disinfectant, but were detected in houses treated with other disinfectants. The high-throughput sequencing results revealed that the combination of multiple disinfectants exhibited a good disinfection efficacy and that this technique could disinfect the air of broiler houses. These results will help guide the development of a reasonable program for broiler house disinfection.