Quantification of wildlife visits to pig farms via camera traps in Japan.

Infectious diseases in livestock not only cause significant economic losses but also affect food security. Although wildlife may be involved in these infectious diseases by serving as reservoirs, research has primarily focused on livestock and related species. Moreover, while these species represent a potential threat in wildlife-borne infectious diseases, comprehensive surveys of the presence of various species are limited. In this study, we aimed to quantitatively investigate the occurrence of various mammals and birds at three pig farms in Japan. We conducted camera trap surveys from October 15, 2020, to March 24, 2022, and determined the relative abundance index inside and outside the sanitary control zone. Wild boar (Sus scrofa), sika deer (Cervus nippon), and Japanese serow (Capricornis crispus) were photographed only outside the sanitary control zone. In contrast, small and medium-sized mammals, such as feral cats (Felis catus), raccoons (Procyon lotor), and rodent species (Muridae), and birds, such as the rufous oriental turtle dove (Streptopelia orientalis) and crows of the genus Corvus, were photographed both inside and outside the sanitary control zone. This comprehensive quantitative evidence suggests that various mammals and birds may be in indirect contact with livestock, highlighting the need to improve biosecurity at livestock farms. Moreover, while fences are effective against large mammals, they are inefficient against small to medium-sized mammals and birds. Therefore, the results of this study provide important insights into enhancing biosecurity on livestock farms by strengthening physical fencing, disinfecting clothing and equipment, and complying with standards of hygiene management.

Assessing mammal fence crossing and local fence management in relation to classical swine fever spread in Japan.

Infectious diseases at the wildlife-livestock-human interface have become a crucial issue, and evidence-based measures are growing increasingly important. One countermeasure against animal diseases in wildlife is using fencing to contain and reduce disease spread and transmission rates between wild populations; however, quantitative assessments on fencing are rare. Moreover, existing research on fencing has highlighted knowledge gaps on the social and ecological aspects relevant to the use and design of fences. To control the spread of classical swine fever, fences were installed from the east to west in Gifu Prefecture, Japan, by March 2019, with the aim of restricting wild boar movement. To clarify the process of installation and maintenance of the fences, we conducted semi-structured interviews with prefectural government officers in Gifu Prefecture. Additionally, we installed infrared-triggered cameras at fence locations with and without gaps to evaluate the fence permeability of mammals. We used a generalized linear mixed model to evaluate the relationship between the presence of gaps and the relative abundance and permeability of each mammal. Our findings showed that the occurrence of gaps was inevitable during the installation and management of wide-area perimeter fence in Japan, partly because of social factors. For example, fences could not be installed on roads that were frequently used by residents and were not adequately maintained owing to budgetary reasons in some cases. Analysis of footage from the infrared-triggered cameras revealed that several mammal species crossed the fence at gaps and even had the ability to cross the gapless parts of the fences. Wild boars crossed through the gaps regularly. It is possible that Sika deer, Japanese serows, raccoons, Japanese badgers, raccoon dogs, Japanese macaques, and feral cats crossed through fence gaps because their relative abundance was high at gap locations. In contrast, Japanese hares slipped through the fence mesh rather than crossing through the gaps. In conclusion, we suggest that coordination and collaboration among related parties, a sufficient supply of fence materials, and securing a budget for fence maintenance are important for fence installation and maintenance. Furthermore, as fence gaps are inevitable, technical development of countermeasures for these gaps could be effective.

The potential negative impacts of the classical swine fever virus on wild boar population in Gifu prefecture, Japan.

There is a possibility that classical swine fever (CSF) virus outbreak has negative impacts on wild boar. To adequately manage native wild boar populations, wildlife managers need to gather the field data on wild boar and implement population management practices. We aimed to report the relative abundance index of wild boar before and after this outbreak. Our results showed that relative abundance index declined from 2017 (8.88 wild boars/100 trap days) to 2019 (2.03 wild boars/100 trap days), because of the negative impact of this virus and continuous culling programs. Although the eradication risk from the synergistic effect is low, wildlife managers need to consider the relationship between the trade-off between the risk of CSF and the conservation ecology risk of native species eradication.

Clonal Spread of Quinolone-Resistant Escherichia coli among Sika Deer (Cervus nippon) Inhabiting an Urban City Park in Japan.

The emergence and dissemination of resistance to clinically important antimicrobials in wild animals is of great concern. The aim of our study was to reveal the prevalence and intraspecies dissemination of quinolone-resistant Escherichia coli (QREC) in sika deer (Cervus nippon) in Nara Park, a famous tourist spot in Japan. Fecal samples were collected from 59 wild deer in Nara Park between July and October 2018. We isolated QREC using deoxycholate-hydrogen sulfide-lactose agar containing nalidixic acid and subjected it to antimicrobial susceptibility testing. The mutations in the quinolone resistance-determining region (QRDR) of the gyrA and parC genes of the isolates were analyzed and fragment patterns of genomic DNA were compared by pulsed-field gel electrophoresis (PFGE). A total of 105 QREC isolates were obtained from 41 deer (70%). All isolates had mutations within the QRDR. Other than quinolone resistance, QREC isolates also showed resistance to various other antimicrobial agents. The QREC isolates were classified into 15 PFGE clusters, of which seven were observed in multiple deer. Our results suggest clonal transmission of QREC in a high-density deer population. Spread of QREC in deer inhabiting a tourist location could have potential impact on public health.

Application of long-term collected data for conservation: Spatio-temporal patterns of mortality in Japanese serow.

Monitoring the mortality of wildlife provides basic demographic information to support management plan preparation. The utility of mortality records for conservation measures was investigated in the Japanese serow, focusing on temporal trends and spatial distribution. Using the mortality records of Japanese serow from 2006 to 2018 in Gifu prefecture, cause-specific mortality was categorized into five groups (disease, accident, vehicle collision, parapoxvirus infection, and unknown), and the sex ratios were examined. A state space model was used to analyze the time series for the monthly mortalities, and kernel estimation was used for the spatial distribution of the parapoxvirus infection. Land cover type around the detection point was also reported. Disease, accident, and vehicle collision mortality were similar, and 30% of mortality was of anthropogenic origin. The number of mortality records for males was higher, and the larger home range of males could account for this. The state space model showed moderate increases in monthly mortalities over time and a seasonal variation with the highest level in spring and lowest in winter. Land cover analysis demonstrated a temporal increase in the proportion of human settlement areas, suggesting the change of the Japanese serow habitat. The proximity of Japanese serow to human settlements contributed to increase in mortality records. The point pattern analysis indicated spatial clustering for parapoxvirus infection in the area where an epidemic had occurred in the past. Several measures are recommended; however, mortality records can help develop improved conservation plan.

Monitoring relative abundance index and age ratios of wild boar (Sus scrofa) in small scale population in Gifu prefecture, Japan during classical swine fever outbreak.

Although the first cases of classical swine fever were reported in 2018, no studies have explored this impact on wild boar populations in Japan. Comparing the relative abundance indices and age ratios in the wild boar population before and after the outbreak, we investigated the impact of classical swine fever virus on wild boar population dynamics in August 2017-December 2019. Relative abundance indices declined from 2017 to 2019 drastically, while there were no significant differences in age ratios throughout the study period. Consequently, wildlife managers should consider that wild boars continue to contract classical swine fever virus, and they should intensively implement countermeasures in agricultural lands and in pig farms, in addition to wild boar population management.

Possible transmission of Sarcoptes scabiei between herbivorous Japanese serows and omnivorous Caniformia in Japan: a cryptic transmission and persistence?

BACKGROUND: Two transmission patterns of Sarcoptes scabiei in host mammal communities have been reported based on microsatellite-level genetic studies in the last two decades. While one involves restrictions among different host taxa, the other is associated with predator-prey interactions between different host taxa. In contrast to these observations, the present study reports a possible irregular case of transmission of S. scabiei between herbivorous Japanese serow and omnivorous Caniformia mammals in Japan, though under very weak predator-prey relationships. METHODS: DNA from 93 Sarcoptes mites isolated from omnivorous Caniformia (such as the domestic dog, raccoon dog, raccoon and Japanese marten), omnivorous Cetartiodactyla (wild boar) and herbivorous Cetartiodactyla (Japanese serow) in Japan were analyzed by amplifying nine microsatellite markers. Principal components analyses (PCA), Bayesian clustering analyses using STRUCTURE software, and phylogenetic analyses by constructing a NeighborNet network were applied to determine the genetic relationships among mites associated with host populations. RESULTS: In all the analyses, the genetic differentiation of Sarcoptes mites from wild boars and Japanese serows was observed. Conversely, considerably close genetic relationships were detected between Caniformia-derived and Japanese serow-derived mites. Because the predator-prey interactions between the omnivorous Caniformia and herbivorous Japanese serow are quite limited and epidemiological history shows at least a 10-year lag between the emergence of sarcoptic mange in Japanese serow and that in Caniformia, the transmission of S. scabiei from Caniformia to Japanese serow is highly suspected. CONCLUSIONS: The close genetic relationships among mites beyond Host-taxon relationships and without obvious predator-prey interactions in Caniformia and Japanese serow deviate from previously reported S. scabiei transmission patterns. This type of cryptic relationship of S. scabiei populations may exist in local mammalian communities worldwide and become a risk factor for the conservation of the remnant and fragmented populations of wild mammals.

An immunohistochemical study on testicular steroidogenesis in the Sunda porcupine (Hystrix javanica).

In the testes of the Sunda porcupine (Hystrix javanica), the expression of the steroidogenic acute regulatory protein (StAR) and steroidogenic enzymes, such as cytochrome P450 side chain cleavage (P450scc), 3ß-hydroxysteroid dehydrogenase (3ß-HSD), cytochrome P450 17α-hydroxylase (P450c17) and cytochrome P450 aromatase (P450arom), was immunohistochemically examined to clarify the location of steroidogenesis. In this study, complete spermatogenesis (spermiogenesis) was observed in the testes of the examined Sunda porcupine, and spermatozoa of the Sunda porcupine had a spatulate sperm head unlike that of rats and mice which has an apical hook. On immunostaining of StAR, P450scc, 3ß-HSD, P450c17 and P450arom, immunoreactivity for all proteins was only detected in the Leydig cells and not observed within the seminiferous tubules, suggesting that the Leydig cells can synthesize both androgen and estrogen from cholesterol in the Sunda porcupine testes.

Serological and histological evaluation of species-specific immunocontraceptive vaccine antigens based on zona pellucida 3 in the small Indian mongoose (Herpestes auropunctatus).

The small Indian mongoose (Herpestes auropunctatus) was introduced to Japanese islands and has impacted on the island's biodiversity. Population control has been attempted through capturing but its efficiency has rapidly declined. Therefore, new additional control methods are required. Our focus has been on the immunocontraceptive vaccines, which act in an especially species-specific manner. The amino-acid sequence of the mongoose ovum zona pellucida protein 3 (ZP3) was decoded and two types of synthetic peptides (A and B) were produced. In this study, these peptides were administered to mongooses (each n=3) and the sera were collected to verify immunogenicity using ELISA and IHC. Treated mongoose sera showed an increasing of antibody titer according to immunizations and the antigen-antibody reactions against the endogenous mongoose ZP. In addition, IHC revealed that immune sera absorbed with each peptide showed a marked reduction in reactivity, which indicated the specificity of induced antibodies. These reactions were marked in peptide A treated mongoose sera, and the antibody titer of one of them lasted for at least 21 weeks. These results indicated that peptide A was a potential antigen, inducing autoantibody generation. Moreover, immunized rabbit antibodies recognized mongoose ZP species-specifically. However, the induction of robust immune memory was not observed. Also, the actual sterility effects of peptides remain unknown, it should be verified as a next step. In any case, this study verified synthetic peptides we developed are useful as the antigen candidates for immunocontraception of mongooses.

Molecular identification of the Cryptosporidium deer genotype in the Hokkaido sika deer (Cervus nippon yesoensis) in Hokkaido, Japan.

The protozoan Cryptosporidium occurs in a wide range of animal species including many Cervidae species. Fecal samples collected from the Hokkaido sika deer (Cervus nippon yesoensis), a native deer of Hokkaido, in the central, western, and eastern areas of Hokkaido were examined by polymerase chain reaction (PCR) to detect infections with Cryptosporidium and for sequence analyses to reveal the molecular characteristics of the amplified DNA. DNA was extracted from 319 fecal samples and examined with PCR using primers for small-subunit ribosomal RNA (SSU-rRNA), actin, and 70-kDa heat shock protein (HSP70) gene loci. PCR-amplified fragments were sequenced and phylogenetic trees were created. In 319 fecal samples, 25 samples (7.8 %) were positive with SSU-rRNA PCR that were identified as the Cryptosporidium deer genotype. Among Cryptosporidium-positive samples, fawns showed higher prevalence (16.1 %) than yearlings (6.4 %) and adults (4.7 %). The result of Fisher's exact test showed a statistical significance in the prevalence of the Cryptosporidium deer genotype between fawn and other age groups. Sequence analyses with actin and HSP70 gene fragments confirmed the SSU-rRNA result, and there were no sequence diversities observed. The Cryptosporidium deer genotype appears to be the prevalent Cryptosporidium species in the wild sika deer in Hokkaido, Japan.

Coexistence of two different genotypes of Sarcoptes scabiei derived from companion dogs and wild raccoon dogs in Gifu, Japan: The genetic evidence for transmission between domestic and wild canids.

Sarcoptes scabiei is the causal agent of sarcoptic mange in domestic/companion dogs (Canis lupus familiaris) and raccoon dogs (Nyctereutes procyonoides). Although there have been successful cases of experimental transmission of S. scabiei from mangy wild Canidae hosts to healthy dogs, and suspected cases of transmission between raccoon dogs and companion dogs, no clear-cut evidence has been obtained. In the present study, the genetic relationships between Sarcoptes mites from raccoon dogs and companion dogs living in the same region were elucidated.One hundred and thirty Sarcoptes mites from 22 raccoon dogs and 5 companion dogs were collected from the Gifu area in Japan. Using 9 microsatellite markers, the genotypes were compared, and the genetic structure of these mites was analyzed. In 6 pairs of companion dog- and raccoon dog-derived mites, 17 out of the 18 alleles analyzed were identical. Using a Bayesian approach, these 130 mites were separated into at least two groups, and companion dog- and raccoon dog-derived mites were segregated into both groups. In addition, comparatively large numbers of alleles at these loci were revealed by comparison with data from past studies. These results demonstrated that the host specificity at the 9 microsatellite-level could not be confirmed, strongly suggesting the transmission of Sarcoptes mites between raccoon dogs and companion dogs. This is the first report to provide a genetic evidence of Sarcoptes transmission between domestic and wild mammals in the natural environment. The possibility of a prior introduction of mites with novel genotypes (e.g., spillover of sarcoptic mange from domestic/companion dogs to raccoon dogs) could not be eliminated when considering the cause of the large number of alleles, and the coexistence of 2 mite groups in sympatric raccoon dogs and companion dogs in this local area.

Isolation and antimicrobial susceptibility of Plesiomonas shigelloides from great cormorants (Phalacrocorax carbo hanedae) in Gifu and Shiga Prefectures, Japan.

Plesiomonas shigelloides is a causal agent of gastroenteritis, sepsis and meningitis in humans. We examined the prevalence of P. shigelloides among great cormorants (Phalacrocorax carbo hanedae) in Japan and the antimicrobial susceptibility of isolates. P. shigelloides was isolated from 33 (47.8%) of 69 fecal samples from great cormorants in 2014. All 33 isolates were subjected to antimicrobial susceptibility testing using broth microdilution methods, which showed resistance to ampicillin (31 isolates, 93.9%), tetracycline (two isolates, 6.1%) and trimethoprim (one isolate, 3.0%). The high prevalence of P. shigelloides in the great cormorants implicates the possible microbiological risk to public health.

Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations.

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17ß and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17ß, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17ß after copulation.

Interaction of peptide-bound beads with lipopolysaccharide and lipoproteins.

We previously reported the generation of lipopolysaccharide (LPS)-binding peptides by phage display and chemical modification. Among them, a dodecapeptide designated Li5-025 (K'YSSSISSIRAC'; K' and C' denote d-lysine and d-cysteine, respectively) showed a high binding affinity for LPS and was resistant to protease digestion (Suzuki et al., 2010). In the current study, Li5-025-bound silica beads, hereafter referred to as P-beads, were generated and found to be devoid of LPS-neutralizing activity. Thus, LPS bound to the P-beads could be directly used in the Limulus amebocyte lysate (LAL) assay. P-beads bound LPS dissolved in solutions of ethanol, pH4, pH10, and 0.5M NaCl and LPS bound to the P-beads was quantitatively assayed. The sensitivity of this assay was observed to be approximately 0.1pg/mL LPS. P-beads bound LPS dissolved in antithrombin III (AT III) solution which is a strong inhibitor of activated factors C and B as well as the clotting enzyme in the LAL assay; the inhibitory effect of AT III was completely reversed upon washing the P-beads with 25% acetonitrile. This was employed as the first step for the detection of free LPS in plasma using the LAL assay. LPS added to human plasma at 0°C followed by application to the P-beads and subsequent washing with 25% acetonitrile resulted in low LPS activity as detected by the LAL assay. However, further washing of the P-beads with 0.1% Triton X100 in 25% acetonitrile resulted in high LPS activity. This is the first instance of quantitative detection of free LPS in plasma using the LAL assay, and the sensitivity of this method was observed to be 1pg/mL of LPS. The proteins eluted in the 0.1% Triton X-100 wash were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Two protein bands of 28kDa and 18kDa were predominantly observed. Mass spectrometry analysis revealed that the 28kDa and 18kDa bands corresponded to apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II), respectively. ApoA-I and apoA-II are components of high density lipoprotein (HDL). Thus, it is likely that the P-beads-bound LPS was sequestered by HDL, resulting in neutralization of its toxicity. This study showed that by using P-beads, free LPS in plasma can be quantitatively measured by the LAL assay at a concentration of 1pg/mL.

Detection of Rickettsia tamurae DNA in ticks and wild boar (Sus scrofa leucomystax) skins in Shimane Prefecture, Japan.

We used 24 wild boars trapped from December 2009 to January 2010 and a further 65 from July 2010 to August 2010 in Misato Town, Shimane Prefecture, Japan. We collected blood, spleens, skins and ticks from the wild boars, which were examined for rickettsial infections using polymerase chain reaction (PCR) primers for the genes rickettsial 17-kDa antigen and citrate synthase (gltA). We amplified Rickettsia tamurae AT-1 DNA from the tick Amblyomma testudinarium and from wild boar skins where ticks attached. Antibodies against spotted fever group Rickettsia were detected in wild boar sera using immunofluorescence, whereas blood and spleen samples contained no rickettsial DNA. This study suggests that wild boars have a role as an amplifier and a transporter of A. testudinarium, which harbor R. tamurae. One case of R. tamurae infection in humans was reported in Shimane Prefecture. Therefore, R. tamurae infections in humans might increase, if wild boar populations and their habitats expand.

Sex determination of sika deer (Cervus nippon yesoensis) using nested PCR from feces collected in the field.

We describe a method for determining the sex of sika deer (Cervus nippon yesoensis) from feces collected in the field. Using a nested polymerase chain reaction (nested PCR), partial sequences of the sex determination region of the Y chromosome (SRY) gene and X zinc finger protein (ZFX) gene were amplified. In 19 individuals with sex information, the correct sex was successfully detected and sequences of target amplicons were completely matched between muscle and feces from the rectum. Among 75 fecal samples collected noninvasively in the field, 68-71 samples (90.7-94.7%) yielded successful sex determinations. Using this technique, feces collected in the field would enhance the utility of genetic analysis. As a result, instead of biomaterials, these samples can serve as new or alternative materials. Finally, it can be expected that this technique will contribute to reveal in advanced detail of the population dynamics and genetic diversity that needed to carry out effective population control and to reduce the extinction risk of sika deer.

Genetic characteristics and antimicrobial resistance of Escherichia coli from Japanese macaques (Macaca fuscata) in rural Japan.

Escherichia coli was isolated from wild and captive Japanese macaques (Macaca fuscata) to investigate the risk of zoonotic infections and the prevalence of antimicrobial-resistant Escherichia coli in the wild macaque population in Shimokita Peninsula, a rural area of Japan. We collected 265 fresh fecal samples from wild macaques and 20 samples from captive macaques in 2005 and 2006 for E. coli isolation. The predominant isolates were characterized by serotyping, virulence gene profiling, plasmid profiling, pulsed-field gel electrophoresis (PFGE), and microbial sensitivity tests. In total, 248 E. coli strains were isolated from 159 fecal samples from wild macaques, and 42 E. coli were isolated from 17 samples from captive macaques. None of the virulence genes eae, stx, elt, and est were detected in any of the isolates. The relatedness between wild- and captive-derived isolates was low by serotyping, PFGE, and plasmid profiling. Serotypes O8:H6, O8:H34, O8:H42, O8:HUT, O103:H27, O103:HNM, and OUT:H27 were found in wild macaque feces; serotypes O157:H42 and O119:H21 were recovered from captive macaques. O-and H-serotypes of the 26 isolates were not typed by commercial typing antisera and were named OUT and HUT, respectively. Twenty-eight isolates had no flagellar antigen, and their H-serotypes were named HNM. Similarity of PFGE patterns between wild-derived isolates and captive-derived isolates was <70%. No plasmid profile was shared between wild-derived and captive-derived isolates. The prevalence of antimicrobial-resistant E. coli was 6.5% (n=62) in wild macaques, and these isolates were resistant to cephalothin. We conclude that wild Japanese macaques in Shimokita Peninsula were unlikely to act as a reservoir of pathogenic E. coli for humans and that antimicrobial-resistant E. coli in wild macaques may be derived from humans.

Evaluation of stored body fat in nuisance-killed Japanese black bears (Ursus thibetanus japonicus).

We evaluated the stored body fat of Japanese black bears (Ursus thibetanus japonicus) killed as nuisances in Gifu and Fukushima prefectures, Japan, during 2005-2007. We employed femur marrow fat (FMF), modified kidney fat index (mKFI), and abdominal subcutaneous fat (ASF) as indices for quantitative evaluation. We examined the basic characteristics of these indices, such as seasonality, age and sex dependency, and the quantitative relationship among them. mKFI and ASF increased towards the beginning of the denning period (December), while FMF was relatively stable throughout the sampling period (July-December). In cubs, all indices showed significantly lower values than in the older age classes. There seemed to be a catabolizing order between FMF and mKFI, but not between mKFI and ASF. We also evaluated the yearly change in the indices, and discussed its relevance to the incidence of bear intrusion into human residential areas. Bears nuisance-killed in summer (July-September) 2006 had a significantly larger amount of stored body fat than those killed in summer 2007, although the number of nuisance kills was larger in 2006 than in 2007. This suggests that poor nutritional condition is not a direct cause of bear intrusion.

Molecular design of LPS-binding peptides.

Lipopolysaccharide (LPS), a major constituent of the outer membrane of Gram-negative bacteria, is highly toxic and can cause sepsis or septic shock. Therefore, detection of LPS and the ability to neutralize its toxicity is important. We previously obtained a strong LPS-binding peptide, Li5-001, using the phage display method (Matsumoto et al., 2010. J. Microbiol. Methods. 82, 54-58). We modified the sequence the amino acid sequence of this peptide (KNYSSSISSIHAC), by replacing and deleting amino acids to obtain higher LPS-binding affinity and greater resistance to protease digestion. Consequently we obtained a dodecapeptide, Li5-025 (K'YSSSISSIRAC', K' and C' are D-forms of K and C, respectively) which showed a high affinity for LPS, approximately 1000 folds higher affinity than Li5-001 and Kd value of 0.01 nM. By replacing both N- and C-terminal amino acids from L-type to D-type, the peptide was rendered resistant to protease digestion without altering its overall binding capacity.

Lipopolysaccaride-binding peptides obtained by phage display method.

Lipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria. It has strong toxicity and might cause sepsis or septic shock. Thus early detection of LPS and neutralization of LPS toxicity are required. We obtained several new LPS-binding peptides using a phage display method. We synthesized 3 of these peptides and analyzed their binding affinity and capacity to LPS. One of these peptides, named Li5-001, showed high binding affinity to LPS and lipid A; the K(d) values were 10 and 1 nM, respectively. Li5-001 showed a high binding capacity to LPS, and was estimated to bind 130 ng LPS/mg, which is higher than that of polymyxin B (80 ng LPS/mg); however, its LPS-neutralizing activity was low. Li5-001 coupled with beads will be useful for eliminating endotoxin contamination from pharmaceuticals. Its low LPS-neutralizing activity allows to be used in the Limulus amebocyte lysate test without eluting LPS from the Li5-001 coupled beads.