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The present study reports the isolation of Clostridium perfringens from samples comprising of freshwater fish and fish products from Kolkata city of India, and determining their genotypes and antibiogram profile. A total of 102 samples consisting of intestinal and gill samples from fresh water fish (n=69) and fish products including fish pickles, fish curry and fried fish (n=33) were collected randomly from retail shops and restaurants. On cultural isolation and biochemical characterization, 24 (23.52%) samples [17 (24.63%) from fresh water fish (n=69) and 07 (21.21%) from fish products (n=33)] were presumptively identified as C. perfringens positive. The genotyping of the recovered C. perfringens isolates was done by amplifying species specific 16S rRNA gene and four major lethal toxin genes viz., alpha toxin gene (cpa), beta toxin gene (cpb), epsilon toxin gene (εtx) and iota toxin gene (ιtx). Apart from these, enterotoxin gene (cpe) and beta2 toxin gene (cpb2) were also targeted. In PCR assays, all the 24 (100%) isolates [17 (70.83%) from fresh water fish and 07 (29.17%) from fish products] were found to harbor species specific 16S rRNA and cpa toxin gene, however, 17 (70.83%) cpa positive isolates [12 (70.58%) from fresh water fish and 05 (71.42%) from fish products] were also found to harbor additional cpb2 toxin gene, while none of the isolates were found to be positive for cpb, εtx, ιtx and cpe genes. Based on these results, all the isolates were confirmed as C. perfringens type A (containing only alpha toxin gene). On antibiotic sensitivity testing, 76.47% of the isolates were found to be multidrug resistant with ciprofloxacin and amoxicillin/clavulanic acid as being the most sensitive drugs. Report regarding isolation and molecular characterization of C. perfringens from fish and fish products especially from Kolkata does not exist as well as from other regions of India are very scanty. The present findings suggest that fish may be considered as a potential source of C. perfringens type A infection to human populations through food chain and the high antibiotic resistance observed may pose serious public health concerns. Further detailed molecular epidemiological and antibiogram studies are suggested for designing and adapting appropriate prevention and control strategies for countering this important pathogen and its food-borne zoonotic concerns. [ABSTRACT FROM AUTHOR]

The article presents a study that determined the presence of virulence genes and enterotoxigenicity status in antibiotic resistant and sensitive isolates of Staphylococcus aureus from buffalo mastitis cases. The study recovered isolates of S. aureus from 75 buffaloes with clinical-mastitis of different periurban herds. It tested the isolates for antimicrobial susceptibility against penicillin, cephotaxime, ciprofloxacin, and amoxyclav.

Aim:  To assess the extent of Listeria monocytogenes in causation of human spontaneous abortions by isolation methods and PCR analysis for the presence of virulence-associated genes. Methods and Results:  A total of 305 samples comprising blood, urine, placental bits, faecal and vaginal swabs were collected from 61 patients with spontaneous abortions. Listeria spp. were isolated from 10 samples collected from nine (14·8%) patients. Confirmation of these isolates was based on biochemical tests, haemolysis on blood agar, CAMP test, phosphatidylinositol-specific phospholipase C (PI-PLC) assay followed by in vivo pathogenicity tests and multiplex PCR to detect virulence-associated genes ( prfA , plcA , hlyA , actA and iap). Three isolates were confirmed as L. monocytogenes. Of these, two isolates turned out to be pathogenic and found to posses all five genes. However, the remaining two haemolytic L. monocytogenes isolates lacking the plcA gene and activity in the PI-PLC assay were found to be nonpathogenic by in vivo tests. Conclusions:  The occurrence of pathogenic L. monocytogenes in cases of spontaneous abortions was 3·3%. It seems that the plcA gene and its expression have an important role as essential virulence determinants in pathogenic Listeria spp. Significance and Impact of the Study:  The recovery of pathogenic L. monocytogenes isolates from cases of spontaneous abortion indicates the significance of listeric infection in pregnant women. [ABSTRACT FROM AUTHOR]

Q fever (coxiellosis), caused by Coxiella burnetii, is an emerging or re-emerging zoonotic disease of public health significance and with worldwide distribution. As a causal agent of the one among the 13 global priority zoonoses, having the infectious dose as low as one bacterium, C. burnetii has been regarded as an obligate intracellular bacterial pathogen. The agent has been classified as a Group B bioterrorism agent by the Centre for Disease Control and Prevention (CDC), and the disease is included in the World Organisation for Animal Health (OIE) list of notifiable diseases. It is mainly transmitted through airborne route in humans and animals. Isolation of C. burnetii, using standard routine laboratory culture techniques was impossible until formulation of axenic-based medium. However, it is still to be included among routinely isolated laboratory pathogen, accounting prolonged incubation period (~7 days) and requirement of specific oxygen concentration (2.5% O 2 ). Therefore, indirect diagnostic tools have been mainly used for its diagnosis. So far serology has been mostly used for testing for C. burnetii infection. The detection of C. burnetii DNA by PCR in various clinical samples have also been widely used. The disease has remained largely under-reported, underdiagnosed and as a masked zoonosis; and therefore, needs to be explored through well-planned scientific studies for knowing its true status and likely it impact in humans and animals by employing state-of-the-art diagnostics, identifying its diverse and new host range, as well as risk factors involved in different geo-climatic, behavioural and social settings as well as risk groups. Here, we reviewed the current approaches used for the detection of C. burnetii infection in humans and animals at the population and individual level., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The present study evaluated intracellular antibacterial efficacy of two short-chain cationic antimicrobial peptides (AMPs) namely, Cecropin A (1-7)-Melittin and lactoferricin (17-30) against three field strains of multi-drug resistant Salmonella Enteritidis. Initially, antimicrobial ability of both the AMPs was evaluated for their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against multi-drug resistant S. Enteritidis strains. Besides, the AMPs were evaluated for its in vitro stability (high-end temperatures, proteases, physiological concentrations of cationic salts and pH) and safety (haemolytic assay in sheep erythrocytes; cytotoxicity assay in murine macrophage RAW 264.7 cell line and human epithelioma HEp-2 cell line and beneficial gut lactobacilli). Later, a time-kill assay was performed to assess the intracellular antibacterial activity of Cecropin A (1-7)-Melittin and lactoferricin (17-30) against multi-drug resistant S. Enteritidis in RAW 264.7 and HEp-2 cells. The observed MBC values of Cecropin A (1-7)-Melittin and lactoferricin (17-30) against multi-drug resistant S. Enteritidis (128 μM; 256 μM) were generally twice or four-fold greater than the MIC values (64 μM). Further, both the AMPs were found variably stable after exposure at high-end temperatures (70 °C and 90 °C), protease treatment (trypsin, proteinase K, lysozyme), higher concentration of physiological salts (150 mM NaCl and 2 mM MgCl 2 ) and hydrogen ion concentrations (pH 4.0 to 8.0). Both the AMPs were found non-haemolytic on sheep erythrocytes, revealed minimal cytotoxicity in RAW 264.7 and HEp-2 cells, and was tested safe against beneficial gut lactobacilli (L. acidophilus and L. rhamnosus). Intracellular bacteriostatic effect with both cationic AMPs against multi-drug resistant S. Enteritidis was evident in RAW 264.7 cells; however, in both the cell lines, the significant bactericidal effect was not observed (P > 0.05) with both cationic AMPs understudy against multi-drug resistant S. Enteritidis. Based on the results of the present study, both the cationic AMPs understudy may not be useful for the intracellular elimination of multi-drug resistant S. Enteritidis; hence, further studies such as conjugation of these AMPs with either cell-penetrating peptides (CPP) and/or nanoparticles (NPs) are warranted., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Coxiella burnetii is one of the most contagious pathogen associated with Q fever in humans, while, ruminants act as important source of infection for humans. In the present cross sectional study, a total of 464 samples were collected from 218 goats comprising of 218 sera, 218 blood and 28 milk from various parts of Chhattisgarh and Odisha region, India. Besides, environmental (33; soil- 4, faecal- 10, feed-6, drainage water- 6, drinking water- 7) and rodent (38) samples were also collected from the premises of the animals. Human sera samples (93) were collected from same sampling area comprised of workers at an organized dairy farm (43), and farmers (50). The samples were subjected to PCR targeting the trans and com1 genes and detection of antibodies using commercial ELISA kits. An overall 14.22% (95% CI: 10.2-19.47%) of the goat samples were positive using either PCR or ELISA. While, by using PCR and ELISA, 11.93% (26/218) and 9.63% (21/218) of the samples were positive for C. burnetii. A higher seropositivity (46.24%; 95% CI: 36.46-56.32%) was observed for antibodies against C. burnetii in samples collected from humans. None of the human, environmental and rodent samples were positive for C. burnetii using PCR. This seems to be the first cross sectional study to focus the hidden threat of coxiellosis among goat population and associated risk factors in India., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

We explored and evaluated for the first time colorimetric nitrocefin assay in conjunction with the double disc test and PCR assay. We suggested the use of nitrocefin assay for rapid screening of ESBL-production by Enteroaggregative Escherichia coli., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A novel multiplex PCR assay was developed to identify genus Listeria, and discriminate Listeria monocytogenes and its major lineages (LI, LII, LIII). This assay is a rapid and inexpensive subtyping method for screening and characterization of L. monocytogenes., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The in vitro and in vivo antimicrobial effects of Lactobacillus plantarum and Lactobacillus acidophilus were evaluated individually and synergistically against multidrug-resistant enteroaggregative Escherichia coli (MDR-EAEC). In vitro evaluation of each probiotic strain when co-cultured with MDR-EAEC isolates revealed a reduction in MDR-EAEC counts (eosin-methylene blue agar) in a dose- and time-dependent manner: probiotics at a dose rate of 10(10) CFU inhibited MDR-EAEC isolates at 72 h post-inoculation (PI), whereas at lower concentrations (10(8) and 10(9) CFU) MDR-EAEC isolates were inhibited at 96 h PI. The synergistic antimicrobial effect of both probiotic strains (each at 10(10) CFU) was highly significant (P < 0.01) and inhibited the growth of MDR-EAEC isolates at 24 h PI. For in vivo evaluation, weaned mice were fed orally with 10(7) CFU of MDR-EAEC. At Day 3 post-infection, treated mice were fed orally with the probiotic strains (each at 10(10) CFU). Compared with the control, post-treatment a significant (P < 0.01) reduction in MDR-EAEC counts was observed in faeces by Day 2 and in intestinal tissues of treated mice by Days 3 and 4 as evidenced by plate count (mean 2.71 log and 2.27 log, respectively) and real-time PCR (mean 1.62 log and 1.57 log, respectively) methods. Histopathologically, comparatively mild changes were observed in the ileum and colon from Days 3 to 5 post-treatment with probiotics; however, from Day 6 the changes were regenerative or normal. These observations suggest that these probiotic strains can serve as alternative therapeutics against MDR-EAEC-associated infections in humans and animals., (Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

In the present study, Salmonella isolates (n=40) recovered from clinical, food, poultry and environmental sources were characterized for serotype identification, genetic diversity and biofilm formation capability. Serotype identification using multiplex PCR assay revealed six isolates to be Salmonella Typhimurium, 14 as Salmonella Enteritidis, 11 as Salmonella Typhi, and the remaining nine isolates unidentified were considered as other Salmonella spp. Most of the Salmonella isolates (85%) produced biofilm on polystyrene surfaces as assessed by microtitre plate assay. About 67.5% isolates were weak biofilm producers and 17.5% were moderate biofilm producers. There was no significant difference in biofilm-forming ability among the Salmonella isolates recovered from different geographical regions or different sources. Among the genetic methods, Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR revealed greater discriminatory power (DI, 0.943) followed by pulsed field gel electrophoresis (PFGE) (DI, 0.899) and random amplification of polymorphic DNA (RAPD) PCR (DI, 0.873). However, composite analysis revealed the highest discrimination index (0.957). Greater discrimination of S. Typhimurium and S. Typhi was achieved using PFGE, while ERIC PCR was better for S. Enteritidis and other Salmonella serotypes. A strong positive correlation (r=0.992) was observed between biofilm formation trait and clustered Salmonella isolates in composite genetic analysis., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The present study describes the utility of a chromosomal associated fimbrial subunit gene (fimA) for screening 'typical' as well as 'atypical' Enteroaggregative Escherichia coli (EAEC) by PCR and its possible role as a promising molecular marker for rapid detection of 'typical' and 'atypical' EAEC pathotype., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In the present study, a total of 158 blood samples from 148 bovines and 10 dogs having a history of reproductive disorders were screened for Coxiella burnetii by trans-PCR method. In case of bovines, 6.08% (9/148) blood samples comprised of 4.54% (4/88) cattle and 8.33% (5/60) buffaloes turned out to be positive for C. burnetii DNA while all the samples from dogs (10) were found negative. Of the 9 PCR-positive bovine blood samples, the organism could be isolated only from 3 cases of buffaloes by chick embryo inoculation method. Further, to predict the homology and genetic diversity, the recovered C. burnetii isolates designated as Y1, Y3 and Y7 were partially sequenced for IS1111 gene. On phylogenetic analysis, Y3 and Y7 isolates clustered to a common node away from Y1 isolate. This study may enlighten the nature of circulating C. burnetii isolates in different parts of the world. To the best of our knowledge, this appears to be the first report describing phylogenic analysis of C. burnetii isolates based on IS1111 gene sequence., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The study describes a rapid approach for detection of common enteric bacterial pathogens, which involves partial amplification of the 16S rRNA gene by PCR using a colony from selective medium followed by restriction enzyme (RE) digestion using the EcoRI, HindIII and SalI enzymes. On the basis of RE digestion analysis different genera namely, Escherichia, Salmonella, Shigella, Vibrio, Campylobacter, Arcobacter, Yesinia and Listeria were differentiated., (© 2013.)

Listeria monocytogenes is a foodborne pathogen that can cause serious invasive illness, mainly in certain well-defined high-risk groups, including elderly and immunocompromised patients, pregnant women, newborns and infants. In India, this pathogen has been isolated from humans, animals and foods. The incidence of Listeria is generally comparable to those reported elsewhere in the world. In humans, maternal/neonatal listeriosis is the most common clinical form reported. Among animal populations, spontaneous abortions, subclinical mastitis, meningoencephalitis and endometritis were the commonest forms reported. The disease largely remains undiagnosed and under reported. From reported analyses of a variety of foods for Listeria, milk and milk products, meat and meat products, seafood and vegetables have been reported to be contaminated in India. The legal framework for microbiological safety of foods against microbes including L. monocytogenes is summarised. The epidemiological studies would help in understanding of the sources of infection and persistence and their risk assessment, routes of transmission, clinical forms and allow for better management of the infection., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Listeria monocytogenes is a foodborne pathogen associated with severe diseases in humans and animals. The genotypic analysis of 17 L. monocytogenes isolates recovered from humans in India during 2006-2009 using multiplex serotyping PCR allowing serovar predictions, conventional serology and by pulsed field gel electrophoresis (PFGE) is presented. The isolates were recovered from patients exhibiting various clinical conditions. A multiplex-PCR based serotyping assay revealed 88·24% (15/17) of the strains belonging to the serovar group 4b, 4d, 4e and 11·76% (2/17) to the serovar group 1/2b, 3b. Conventional serology indicated that 13 (76·47%) L. monocytogenes isolates to be of serotype 4b, 2 (11·76%) serotype 4d, and 2 (11·76%) serotype 1/2b. Ten ApaI and nine AscI pulsotypes were recognized among the 17 human isolates. PFGE analysis allowed discrimination among isolates of the same serotype and among isolates from the same sampling areas or those isolated from different areas. Thus, PFGE together with multiplex-PCR serotyping allows rapid discrimination of L. monocytogenes strains. In addition, the predominance of L. monocytogenes serotype 4b is of concern, as this serotype has been most frequently associated with human listeriosis outbreaks.

The occurrence of Coxiella burnetii in animals with reproductive disorders was studied. A total of 920 samples (genital and faecal swabs, milk, urine and serum) were collected from cows (88), buffaloes (33), sheep (43) and goats (53) with a history of reproductive disorders and screened for C. burnetii by a PCR assay targeting the repetitive transposon-like region of C. burnetii (trans-PCR), real-time PCR, indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA) and isolation method. The overall prevalence of Q fever in animals with the history of reproductive disorders turned out to be 13.82%. The species-wise prevalence of Q fever among animals was observed to be 12.78% in cattle, 16.66% in buffaloes, 11.04% in sheep and 6.13% in goats. In comparison to IFA, the highest sensitivity (85.18%) was shown by both PCR assays followed by ELISA (74.07%) and isolation method (14.81%) whereas, isolation method was the most specific (100%) followed by both PCR assays (99.47%) and ELISA (98.44%). The high excretion rate of pathogen particularly in milk observed in the study posses a potential public health threat from infected animals., ((c) 2008 Elsevier Ltd. All rights reserved.)

Listeria spp. was isolated from 19.8% of animals with a history of reproductive disorders. A total of 333 faecal, genital swab and blood samples from 111 animals (cattle, buffaloes, sheep and goats) were subjected to PCR to detect virulence-associated genes (prfA, plcA, hlyA, actA and iap) and pathogenicity testing by the phosphatidylinositol phospholipase-C (PI-PLC) assay, and by mouse and chick embryo inoculation. One isolate of Listeria ivanovii recovered from a genital swab from a sheep was found to be pathogenic. Virulence assessment was then carried out on two L. ivanovii and 29 Listeria monocytogenes isolates from various sources using these assays. Haemolytic L. monocytogenes isolates lacking the plcA gene and PI-PLC activity were deemed non-pathogenic when assessed by mouse and chick embryo inoculation tests, in spite of having the hlyA gene. The results suggested that the PI-PLC and PCR assays are reliable in vitro alternatives to in vivo pathogenicity tests for L. monocytogenes., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Clinical samples (n=725) were collected from bovines (n=243) which were positive for mastitis using the California mastitis test (CMT) and somatic cell count (SCC). The clinical samples comprising blood (n=239), milk (n=243), and faecal swabs (n=243) were examined for the presence of pathogenic Listeria spp. Isolation of the pathogen was done using selective enrichment in University of Vermont Medium and plating onto Dominguez-Rodriguez isolation agar. Confirmation of the isolates was based on biochemical tests and Christie, Atkins, Munch-Petersen (CAMP) test followed by pathogenicity testing. Pathogenicity of the isolates was tested by phosphatidylinositol-specific phospholipase C (PI-PLC) assay as well as in vivo tests namely, chick embryo and mice inoculation tests. The isolates were subjected to PCR assay for five virulence-associated genes, plcA, prfA, hlyA, actA and iap. Listeria spp. were isolated from 12 (1.66%) samples. Of these 4 (0.55%) and 1 (0.14%) were confirmed as Listeria monocytogenes and Listeria ivanovii, respectively. L. monocytogenes and L. ivanovii were recovered from milk samples (2) and faecal (3) of mastitic cattle (3) and buffaloes (2). L. monocytogenes recovered from the milk of mastitic cattle and L. ivanovii from the faecal swab of buffalo turned out to be pathogenic. However, the remaining three hemolytic isolates exhibiting positive CAMP test turned out to be negative in PI-PLC assay, chick embryo and mice inoculation. L. monocytogenes and L. ivanovii isolates characterized as pathogenic by PI-PLC assay and in vivo pathogenicity tests were found to possess all the five virulence-associated genes and three genes, plcA, prfA and actA respectively. The remaining three hemolytic but non-pathogenic L. monocytogenes isolates were negative for plcA by PCR. It seems that the plcA gene and its expression (in the PI-PLC assay) have an important role as virulence determinants in pathogenic Listeria spp. In conclusion, the PI-PLC assay and virulence genes targeted PCR (plcA, prfA and hlyA genes for L. monocytogenes and plcA, prfA and actA genes for L. ivanovii) hold a good promise as rapid and reliable in vitro alternatives to in vivo pathogenicity tests.

The isolation of pathogenic Listeria spp. in faecal samples of captive wild animals was studied. Isolation of the pathogen was attempted from the samples by selective enrichment in University of Vermont Medium and plating onto Dominguez-Rodriguez isolation agar, PALCAM agar and modified McBride Listeria agar. Pathogenicity of the isolates was tested by Christie, Atkins, Munch Petersen test, phosphotidylinositol-specific phospholipase C assay, mice inoculation test and chick embryo bioassay. Listeria monocytogenes was isolated from eight (16%) of 50 faecal samples from six different mammals and one bird. Out of eight isolates, one isolate from jackal proved to be pathogenic by all the pathogenicity testing assays. PCR amplification of virulence genes suggested that the isolate was potentially pathogenic.

Listeria monocytogenes, a gram-positive, facultative intracellular pathogen was isolated from buffaloes with a history of reproductive disorders and polymerase chain reaction (PCR) analyses for the presence of virulence-associated genes were conducted. A total of 530 samples of faecal, nasal, vaginal swabs and blood samples from 135 buffaloes were screened. The prevalence of L. monocytogenes and other Listeria spp. was found to be 4.4 and 7.4%, respectively. All isolates were subjected to PCR for virulence-associated genes (prfA, plcA, hlyA, actA and iap) and to pathogenicity testing by the phosphatidylinositol phospholipase C (PI-PLC) assay and mice and chick-embryo inoculation. All L. monocytogenes isolates were hemolytic and positive for the hlyA gene. One L. monocytogenes isolate possessed all five virulence-associated genes and was also positive in the PI-PLC assay as well as in the in vivo pathogenicity tests. The remaining hemolytic L. monocytogenes isolates lacking the plcA gene and PI-PLC assay activity were, however, non-pathogenic via mice and chick-embryo inoculation tests, in spite of having the hlyA gene. The detection of multiple virulence-associated genes, in combination with in vitro pathogenicity tests, must be performed to identify pathogenic L. monocytogenes.

The kinetics of antibody production against phosphatidylinositol-specific phospholipase C (PI-PLC) and the isolation pattern of Listeria monocytogenes from bacteriological samples were studied following oral infection of buffalo calves with 3 x 10(9) cells each of pathogenic L. monocytogenes. Antibodies to PI-PLC appeared by 4-8 days post infection (PI), with a peak between days 7 and 16 PI, when tested by indirect plate-ELISA. Subsequently, antibody titres in all the animals declined and became undetectable on days 26-35 PI onwards until the study concluded on day 211 PI. Dot-ELISA could detect the antibodies to PI-PLC 1-2 days earlier and at higher titres as compared to plate-ELISA. L. monocytogenes could be recovered from faeces, nasal swabs and haemocultures from days 2 to 33, days 2 to 21 and days 11 to 17 PI, respectively. Antibodies to PI-PLC were detected during the course of active infection but their titres declined sharply once animals became culturally negative. Sonicated antigen elicited the highest delayed-type hypersensitivity response, followed by PI-PLC and listeriolysin O.

The isolation of pathogenic Listeria spp. in bacteriological samples, and anti-phosphatidylinositol-specific phospholipase C (anti-PIPLC) antibodies in sera of buffaloes were studied. Isolation of the pathogen was attempted from the samples by selective enrichment in University of Vermont Medium and plating onto Dominguez-Rodriguez isolation agar. Pathogenicity of the isolates was tested by Christie, Atkins, Munch Petersen test and mice incoulation test. Listeria spp. and L. monocytogenes were isolated from 8.8 and 2.4%, and 4.8 and 1.6% of 125 each meat and blood samples, respectively. Out of the 125 samples each of feacal, nasal and vaginal swabs from buffaloes 8 and 4%, 13.6 and 2.4%, and 6.4 and 2.4% were positive for Listeria spp. and L. monocytogenes, respectively. L. ivanovii was confirmed from 0.8% vaginal sample. A total of 125 serum samples were tested by phosphatidylinositol-specific phospholipase C (PIPLC) based indirect ELISA of which 4.0% turned out to be seropositive.

Listeriosis is an important bacterial zoonosis caused by the intracellular pathogen Listeria monocytogenes. The disease has been reported in animals from the Indian subcontinent, usually in the form of sporadic cases but occasionally as outbreaks. Cases of listeriosis arise mainly from the ingestion of contaminated food. Listeriosis has been reported to cause encephalitis, abortion, mastitis, repeat breeding and endometriosis in animals. Listeric infections occur in children and women with a poor obstetric history. The epidemiological aspects and pathogenesis of listeriosis in animals and humans are not yet fully understood. This review offers comprehensive information on experimental studies and field cases in animals and on cases of human listeriosis. There are also sections on isolation from foods, diagnosis and treatment in humans and animals.

The occurrence of Listeria monocytogenes in meat and milk samples, and antilisteriolysin O (ALLO) antibodies in sera of buffaloes were studied. Isolation of the pathogen was attempted from the samples by selective enrichment in University of Vermont Medium and plating onto Dominguez-Rodriguez isolation agar. The pathogenicity of the isolates was tested by Christie, Atkins, Munch Petersen test and mouse inoculation test. Of 167 meat samples 2.4 and 10.17% were positive for L. monocytogenes and Listeria sp., respectively. Of the 64 milk samples 6.25 and 26.13% were positive for L. monocytogenes and Listeria sp., respectively. A total of 284 serum samples were tested by listeriolysin O (LLO)-based indirect enzyme-linked immunosorbent assay of which 25.35% were found to be seropositive. The culture positivity for L. monocytogenes and detection of ALLO did not show any agreement (kappa = 0.035). The prevalence of pathogenic L. monocytogenes in milk and meat and the occurrence of anti-LLO antibodies is of concern from the public health point of view.