Research Note: Lyophilization of hyperimmune egg yolk: effect on antibody titer and protection of broilers against Campylobacter colonization

Abstract

Oral administration of antibodies is a promising strategy against various infectious diseases. Previously, it was demonstrated that passive immunization by providing hyperimmune egg yolk through the feed reduces Campylobacter jejuni colonization in broilers. Campylobacteriosis is the most commonly reported bacterial foodborne zoonosis worldwide, and poultry products are the number one origin of these bacteria for human infection. To date, no effective control measures exist to limit Campylobacter colonization in the chicken's intestinal tract. Here, the effect of lyophilization of hyperimmune egg yolk on protection of broilers against C. jejuni was investigated. During an in vivo trial, broiler chickens were prophylactically given feed with lyophilized hyperimmune or non-immunized egg yolk powder starting from day 1 after hatch. At day 11, broilers were inoculated with C. jejuni according to a seeder model. Five days later, all broilers were euthanized and cecal content was examined for C. jejuni colonization. No decrease in C. jejuni colonization was found. The freeze-drying resulted in a 16-fold decrease of the antibody titer in the yolk powder compared to the fresh yolks, presumably caused by structural changes in the antibodies. In conclusion, applying freeze-dried hyperimmune egg yolk failed to protect broilers against C. jejuni colonization, possibly because lyophilization affected the antibodies' functionality.

Avian campylobacteriosis, prevalence, sources, hazards, antibiotic resistance, poultry meat contamination, and control measures: a comprehensive review

“… Shanker et al (1986) discovered that unless C. jejuni was directly injected into albumin, natural colonization did not occur, even when C. jejuni -challenged eggshells were used. In addition, a number of investigations have failed to differentiate the identical genotypes of C. jejuni in parent farms and their chicken offspring ( Petersen et al, 2001 ; Vandeputte et al, 2020 ). The presence of anti- Campylobacter antibodies in the mother reduces both the vertical transmission and proliferation of the bacteria in newly hatched chickens ( Sahin et al, 2001 ).…”

IgY technology: Methods for developing and evaluating avian immunoglobulins for the in vitro detection of biomolecules

“…In general, eggs are collected weekly, starting 1 wk prior to the first immunization (pre-immune eggs), eggshells are washed or sanitized with 70% ethanol, and stored at 4℃ until further processed for IgY isolation. Lyophilization of egg yolk has also been reported, resulting in an easy-to-mix egg yolk powder with an extended shelf-life[ 45 ].…”

“…Useful information concerning earlier findings on the stability and storage conditions of IgYs has appeared in recent review articles[ 73 ]. Freeze-drying has been used to facilitate long storage of IgYs[ 74 ], though some researchers have reported that freeze-drying may lead to some loss of antigen-binding activity of IgY[ 45 ]. Lyophilization of proteins, including IgYs, induces freezing and dehydration stresses, which may result in protein structural changes or even unfolding[ 75 ].…”

“…Lyophilization of proteins, including IgYs, induces freezing and dehydration stresses, which may result in protein structural changes or even unfolding[ 75 ]. Therefore, the addition of cryoprotectants and lyoprotectants has been recommended to protect IgYs during lyophilization[ 45 ]. Our team has recently evaluated IgYs that were developed against a KLH-conjugate of the polypeptide prothymosin alpha many years ago and kept as lyophilized powder at -30 °C.…”

“…Nevertheless, it is a fast, easy, and low-cost technique that may provide useful information and has, therefore, been used by several researchers to evaluate immunoreactivity of IgYs[ 32 , 34 , 36 , 39 , 76 ]. In most cases, however, evaluation of IgY immunoreactivity involves determination of titer against the target antigen through non-competitive ELISAs (indicative references[ 32 , 35 , 45 , 76 , 78 ]). Moreover, other immunochemical characteristics of the isolated IgYs are assessed, such as putative cross-reactivity with various substances through competitive ELISAs (indicative references[ 31 , 36 , 39 ]).…”