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Blood culture is considered the gold standard test for documenting bacteraemia in patients with suspected bacterial sepsis in veterinary and human medicine. However, blood culture often fails to yield bacterial growth even though the clinical picture is strongly suggestive of bacterial sepsis, or contaminating organisms can overgrow the true pathogen, making accurate diagnosis and appropriate management of this life-threatening condition very challenging. Methodology for collecting blood cultures in equine medicine, and even in human hospitals, is not standardised, and many variables can affect the yield and type of microorganisms cultured. Microbiological culture techniques used in the laboratory and specific sample collection techniques, including volume of blood collected, aseptic technique utilised, and the site, timing and frequency of sample collection, all have substantial impact on the accuracy of blood culture results. In addition, patient-specific factors such as husbandry factors, the anatomical site of the primary infection, and changing microflora in different geographic locations, also can impact blood cultures. Thus, blood cultures obtained in practice may not always accurately define the presence or absence of, or specific organisms causing, bacteraemia in horses and foals with suspected sepsis. Erroneous blood culture results can lead to inappropriate antimicrobial use, which can result in poor outcomes for individual patients and contribute to the development of antimicrobial resistance in the patient's microflora and the environmental microcosm. This review summarises current indications and methodology, and specific factors that may be optimised, for equine blood culture, with particular focus on available literature from neonatal foals with suspected bacterial sepsis. To standardise and optimise blood culture techniques in horses and foals, future research in this area should be aimed at determining the optimal volume of blood that should be collected for culture, and the ideal site, timing, and frequency of sample collection., (© 2022 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

The newly emerging tissue microbiota hypothesis suggests that bacteria found in blood and tissues play a role in host health, as these bacterial communities have been associated with various noncommunicable diseases such as obesity, liver disease, and cardiovascular disease. Numerous reports have identified bacteria in the blood of healthy finfish, indicating bacteremia may not always indicate disease. Current research priorities in aquaculture include the development of technologies and practices that will allow for an effective reduction in antibiotic use for the prevention and treatment of disease. Overall, a better understanding of fish health is needed, particularly among species selected for commercial-scale production. This study investigated blood characteristics of cultured Red Drum Sciaenops ocellatus with the tissue microbiota hypothesis in mind. Bacterial assemblages within the blood were characterized using next-generation sequencing and compared with other various blood characteristics, including innate immune function enzymes, between two fish cohorts reared in aquaculture. A total of 137 prokaryotic operational taxonomic units (OTUs) were identified from the blood of Red Drum. Microbiota diversity and structure varied greatly among individuals, for which the number of OTUs ranged from 4 to 58; however, predicted metagenomic function was highly similar between individuals and was dominated by the metabolism of carbohydrates and amino acids and membrane transport. Communities were dominated by Proteobacteria, followed by Bacteroidetes, Firmicutes, and Actinobacteria. The most commonly identified genera included Acinetobacter, Bacillus, Corynebacterium, and Pseudomonas. Three genera previously identified as containing marine fish pathogens were detected: Corynebacterium, Pantoea, and Chryseobacterium. A subset of bacterial OTUs were positively correlated with superoxide dismutase activity and negatively correlated with lysozyme activity, indicating a relationship between blood microbiota and the innate immune system. The results of this study provide further evidence for the tissue microbiota hypothesis and demonstrate the potential for these bacterial communities to be linked to immunological characteristics often used as biomarkers for fish health., (© 2018 American Fisheries Society.)

Northern ireland disease surveillance, july to september 2017 Bibersteinia trehalosi causing septicaemic pasteurellosis in lambsAbortion due to Streptococcus pluranimalium in cattleLymphoma in cattleAcute fasciolosis in sheepErysipelas in pigsMarek's disease in chickens., (British Veterinary Association.)

This study aims to investigate the bacteria involved in equine omphalitis and their susceptibility to antimicrobial drugs, and consequently to provide guidelines concerning the most suitable treatment protocol in accordance with the clinical, ultrasound and laboratory findings. Forty foals aged between one and 30 days were evaluated in the course of this investigation. An ultrasound examination of all umbilical remnants was carried out carefully in all foals; umbilical swabs were collected for bacteriological examination, and blood samples were collected for blood culture from 19 foals with fever and abnormal blood values. Bacterial omphalitis was observed in 95 per cent of foals and bacterial septicaemia was diagnosed in 11 cases. Enterobacteria and coccoid Gram-positive bacteria were isolated more frequently than Serratia marcescens, Pantoea agglomerans and Trueperella pyogenes Omphalectomy was performed in 77.5 per cent of the foals examined; the remainder were treated only medically with antimicrobial drugs as recommended by antibiotic susceptibility testing performed for all bacteria isolated. Antibiotic therapy was successful in all foals that only received medical treatment; nevertheless, omphalectomy was performed in most cases particularly in situations of clinical decline despite antibiotic therapy and when involvement of umbilical vein, fever and joint disorders were observed., (British Veterinary Association.)

Background: Transient bacteraemia can occur during tooth extraction in humans, and dogs and can lead to severe infectious sequelae. Several case reports describe distant site infections following equine tooth extraction, but the occurrence of bacteraemia during dental surgery has not been evaluated in the horse., Objectives: To determine if transient bacteraemia occurs during tooth extraction in horses, describe isolated organisms and compare these with those found in the diseased teeth., Study Design: Prospective, observational study., Methods: Blood was collected aseptically for blood culture before, during and after oral extraction of incisor, canine or cheek teeth from 20 adult horses undergoing dental extraction that had not received antimicrobial agents for at least 4 weeks prior to surgery. Bacteria found in blood cultures were compared with those found in swab samples obtained from the extracted teeth., Results: Eighteen of 20 horses had positive blood cultures at one or more time points. Streptococcus spp., Actinomyces spp., Fusobacterium spp. and Prevotella spp. were most commonly found. Bacterial genera isolated from swab samples of extracted teeth largely corresponded with those identified in blood cultures., Main Limitations: This study was limited by its use of only conventional bacterial culture, the lack of statistical analysis to explore associations between gingiva score and the occurrence of bacteraemia, and the lack of an age-matched control group of horses not undergoing exodontia., Conclusions: Transient bacteraemia of oral origin commonly occurs during dental extraction in horses. As none of the horses developed complications associated with bacteraemia during the observation period after surgery, the significance of this bacteraemia remains uncertain. The Summary is available in Chinese - see Supporting Information., (© 2016 EVJ Ltd.)

Reasons for Performing the Study: Neonatal sepsis is a common problem in foals and is a primary cause of death in the post natal period. Transient bacteraemia and subsequent host responses have not been described in the equine neonate., Objectives: The primary objective of this study was to determine if transient bacteraemia occurs in foals within the first 72 h of life. Additional objectives included description of bacterial organisms associated with transient bacteraemia and concurrent cytokine gene expression in healthy foals., Study Design: Prospective observational study in healthy foals., Methods: Blood was aseptically collected for bacterial culture from observed spontaneously born foals at birth and 1, 2, 3, 4, 8, 12, 24, 48 and 72 h following birth. Samples taken at birth, 4, 12, 24, 48 and 72 h were analysed for interferon gamma (IFNγ), interleukin (IL)-1, IL-2, IL-6, IL-8, IL-10, IL-18 and monocyte chemotactic protein 1 (MCP1) cytokine gene expression quantified by RT-PCR., Results: Bacteria were cultured from 9 of 70 samples submitted for blood culture. The positive samples were from 4 of the 7 foals, all of which remained healthy throughout and subsequent to the study. All positive blood cultures were from blood samples obtained at 12 h of age or earlier and IL-10 elevation coincided with positive blood cultures in healthy foals. Cytokine gene expression fluctuated with age., Conclusions: Positive blood cultures suggest transient bacteraemia may occur in healthy foals early in the post natal period. Age corrected normal values may be necessary to interpret cytokine concentration in diseased populations., (© 2014 EVJ Ltd.)

In dogs with idiopathic acute haemorrhagic diarrhoea syndrome (AHDS), a serious loss of intestinal mucosal barrier integrity occurs. However, the incidence of bacterial translocation in dogs with idiopathic AHDS is not known. Thus, the objectives of this prospective study were to identify the incidence of bacteraemia, to evaluate the frequency of septic events and the influence of bacteraemia on various clinical and laboratory parameters, duration of hospitalisation and survival of dogs with idiopathic AHDS. The study included 87 dogs with idiopathic AHDS. Twenty-one healthy dogs served as control group. To evaluate clinical significance of bacterial translocation, blood culture results were compared between patients and controls. Clinical and laboratory parameters were compared between patients with positive and negative blood cultures. There was no significant difference in either incidence of bacteraemia between patients with idiopathic AHDS (11 per cent) and controls (14 per cent) or in severity of clinical signs, laboratory parameters, duration of hospitalisation or mortality between blood culture-positive and culture-negative dogs with idiopathic AHDS. The results of this study suggest that the incidence of bacteraemia in dogs with idiopathic AHDS is low and not different from that of healthy control dogs. Bacteraemia does not influence the clinical course or survival and thus antibiotic treatment is not indicated to prevent sepsis., (British Veterinary Association.)

Reasons for Performing Study: The incidence and implications of positive blood cultures in mature horses with diarrhoea is unknown. The diagnosis of bacteraemia may alter treatment and prognosis., Hypothesis: The proportion of horses with diarrhoea that are blood culture positive is higher than previously assumed and a positive blood culture has a negative impact on survival., Methods: Blood cultures were taken at admission and 24 h after admission from 31 mature horses with diarrhoea., Results: Nine (29%) horses were blood culture positive within 24 h of admission. Organisms isolated included Corynebacterium spp. (n = 6), Streptococcus spp. (n = 2), Pantoea agglomerans (n = 1), Gram-negative rod (n = 1), Bacillus spp. (n = 1) and yeast (n = 1). Horses with positive blood cultures were significantly less likely to survive. Prior treatment with antimicrobial drugs had no significant effect on blood culture status. Horses with positive blood cultures had a significantly higher heart rate, packed cell volume (PCV) and plasma potassium concentration at admission, and a higher PCV and lower total plasma protein concentration 24 h after admission., Conclusions: Positive blood cultures occur more frequently than previously reported, and may have a negative impact on survival in horses with diarrhoea., Potential Relevance: Results of blood cultures may be useful in formulating a prognosis for horses with diarrhoea. Further research is required to determine the effect of antimicrobial treatment on outcome.

Blood culture is a diagnostic tool used in confirming bacterial disease in teleostean and elasmobranch fishes. Unlike teleosts, elasmobranchs have a normal microflora in multiple organs, but their blood has generally been considered to be sterile. In regular exams of elasmobranchs conducted at a public aquarium, occasional blood samples have tested positive on culture. This finding prompted a blood culture survey of healthy captive and wild elasmobranchs (sharks and stingrays), which showed that 26.7% of all animals were positive. Stingrays alone showed a 50% occurrence of positive blood cultures, although the total number of animals was low and freshwater species were included in this number. When elasmobranchs other than stingrays were evaluated according to metabolic category, pelagic animals had a higher percentage of positive cultures than nonpelagic animals (38.7% versus 13.9%). These results indicate that a single positive blood culture without other corroborating diagnostics is not sufficient to confirm septicemia in elasmobranchs.

Reasons for Performing Study: Treatment for bacteraemia in foals must be started before the identity of the causative organism is known. Information aiding selection of effective antimicrobials should improve outcome., Objectives: To describe differences in clinical and clinicopathological data and outcome in foals with bacteraemia due to different classes of bacteria., Methods: Records of foals with a positive blood culture, age < 10 days and presenting to a university hospital 1995-2004, were reviewed. Bacterial culture results, subject details, historical information, physical examination findings at admission and clinicopathological data generated during the first 48 h of hospitalisation were analysed. Results from foals with Gram-positive or Gram-negative organisms, single or mixed organism bacteraemias, and with bacteraemia due to 3 commonly isolated organisms were compared., Results: Eighty-five foals met the inclusion criteria. Gram-negative organisms (n = 59) Gram-positive organisms (n = 13) or multiple organisms (n = 19) were cultured from individual foals. Foals with Gram-negative bacteraemia had lower total white blood cell and lymphocyte counts at admission than did those from which only Gram-positive bacteria were cultured. Mixed organism bacteraemia was associated with tachycardia, increased serum concentrations of sodium, chloride and urea nitrogen, acidosis, respiratory distress, recumbency on admission and nonsurvival. Actinobacillus spp. infections were associated with leucopenia, neutropenia, lymphopenia and depression on hospital admission., Conclusions and Potential Relevance: Recognising particular patterns of clinical and clinicopathological findings associated with infection with specific groups of bacteria may, in the future, aid antimicrobial selection and influence prognosis in bacteraemic foals.

An adult male binturong, Arctictis binturong, which had been anorexic and lethargic for seven days became acutely dyspnoeic and died under anaesthesia. A postmortem examination revealed left ventricular hypertrophy with a thrombus occluding the left ventricular chamber. Histological findings included moderate to severe multifocal, vasculocentric myocardial degeneration and necrosis with fibrosis replacing myocardiocytes. Escherichia coli and Proteus mirabilis were grown on cultures. The animal's serum vitamin E and selenium levels were considered adequate. The aetiology of the chronic myocardial changes could not be determined.

A 24-hour-old Hackney ony filly developed signs of weakness, depression and a poor suck reflex, with harsh lung sounds over both fields, and a 48-hour-old Arabian colt from a normal birth which had sucked vigorously developed loose stools and became depressed, weak and anorectic. Both foals had serum IgG concentrations greater than 800 mg/dl, but each had a severe neutropenia with a left shift, and blood cultures from both of them yielded Actinobacillus suis. The A suis isolates had different antimicrobial susceptibility patterns and, in the case of the Arabian, the isolate was resistant to commonly used broad spectrum antimicrobial agents.

In December 1991, an outbreak of Streptococcus bovis septicaemia occurred in a Belgian pigeon loft where 25 male and 25 female racing pigeons were housed. The main clinical signs included inability to fly and poor breeding results. None of the female pigeons and only one male pigeon was able to fly. Nine affected pigeons were necropsied. Histologically a tenosynovitis of the tendon of the deep pectoral muscle was observed in most of them and S bovis was isolated from the canalis triosseus or the shoulder joints of five of the nine pigeons. The pigeons were successfully treated with ampicillin administered in the drinking water for seven days.

A novel composite hypertonic solution for intravenous use was tested in two experimental models, one of endotoxic shock and one of shock linked with dehydration, both in anaesthetised calves. Endotoxic shock was induced with Escherichia coli lipopolysaccharide and was characterised by a low cardiac output, hypoxaemia, acidosis and anuria. Treatment with a small volume of the solution increased cardiac output, improved oxygen carriage, corrected acidosis and stimulated renal function. Experimental dehydration in calves was induced by intraperitoneal mannitol and frusemide diuresis, and was characterised by reduced circulating plasma volume, acidosis and poor peripheral perfusion. Treatment with the new solution corrected the acidosis and stimulated peripheral circulation significantly better than treatment with hypertonic or isotonic saline alone, and also expanded the calves' plasma volume. The new solution was also compared with conventional fluid therapy in clinical small animal practice. Twenty cats and dogs with clinical shock were treated with either small volumes of the hypertonic solution or large volumes of isotonic fluids. The animals treated with small volumes of the hypertonic solution responded better than the animals treated with large volumes of isotonic fluid.

Escherichia coli isolated from farm animals in England and Wales between 1986 and 1991 were examined for their serogroup, fimbrial adhesin and toxin production, and resistance to antimicrobial drugs. Among the 3595 porcine isolates the more common serogroups were O149, O8, O138, O147 and O157. The F4(K88) adhesin was detected in 21 per cent of the cultures, whereas the other adhesins were never present in more than 3 per cent during any year, although there was an upward trend in the prevalence of the F6(987P) antigen. The heat labile enterotoxin was produced by more than 17 per cent of the cultures usually in association with the F4 antigen. The other toxins, heat stable (STa), verocytotoxin (VT) and cytotoxic necrotising factor (CNF) were produced by 5.3, 4.7 and 6.8 per cent of the cultures, respectively. Among the 1383 bovine cultures the more common serogroups were O8, O101 and O17. The F5(K99) adhesin was detected in 9.1 per cent of the cultures, usually in association with STa production. The toxins STa, VT and CNF were produced by 4.4, 2.8 and 8.3 per cent of the cultures, respectively. Among the 407 ovine isolates the more common serogroups were O8, O101 and O78, and 11 per cent of the cultures produced the F5(K99) antigen. The toxins STa, VT and CNF were produced by 1.5, 6.1 and 9.1 per cent of the cultures, respectively. In the case of the 402 poultry isolates the more common serogroups were O78, O2 and O8, which are usually associated with colisepticaemia. Resistance to antibiotics was common, particularly among the bovine isolates.

This study investigated the number of blood culture-positive cattle among 215 animals clinically suspected of having bacterial endocarditis. For animals that were necropsied, the sensitivity, specificity and predictive value of the diagnosis of endocarditis were calculated on the basis of the isolation of the causative bacteria from blood. Furthermore, it was investigated whether the glutaraldehyde coagulation time, total leucocyte count, per cent neutrophil granulocytes, pulse rate and duration of disease could help to discriminate endocarditis from other diseases. Among 138 animals necropsied the sensitivity, specificity and predictive value of blood cultivation were 70.7 per cent, 93.8 per cent and 89.1 per cent, respectively. None of the other measurements could be used to discriminate between endocarditis and non-endocarditis cases.

Fourteen mares and their foals were attended at parturition. After mare-foal bonding, 8 colostrum-deprived (CD) foals were removed from their dams, deprived of colostrum, and provided with an alternative milk source for the first 24 h of life. The mares were milked out every 2-4 h during this period to remove colostrum, after which the CD foals were returned to their mares and allowed to nurse. Six colostrum-fed (CF) foals were allowed to suck colostrum in the normal manner. Foal serum IgG concentration was determined by single radial immunodiffusion (means, CD = 0 mg/dl; CF = 1,508 mg/dl). Accepted methods were used to minimise infections in the neonatal foals. Of the 8 CD foals, 7 demonstrated clinical signs of sepsis. Septicaemia was confirmed in 5 of the 7 septicaemic CD foals by ante-mortem blood culture or by culture of tissue at necropsy. Organisms isolated included: Actinobacillus equuli, Escherichia coli, undifferentiated coliforms, Pseudomonas spp., and Actinomyces pyogenes. Clinically ill foals were treated with antimicrobial drugs, intravenous fluid therapy, flunixin meglumine, and anti-endotoxin hyperimmune serum. Three septicaemic CD foals survived. Four of 7 septicaemic CD foals died or were destroyed. Post-mortem lesions included bacterial embolic pneumonia, glomerulonephritis/nephritis, lymphoid depletion/atrophy, splenic and lymphoid necrosis, hepatitis, septic arthritis, and systemic bacterial embolism. None of the CF foals became septicaemic. One CF foal had foal heat diarrhoea and 1 CF foal had a serum IgG concentration of 160 mg/dl (i.e. failure of passive transfer), but both foals were otherwise normal.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of hypoxia and azotaemia on the pharmacokinetics of amikacin were evaluated in 20 full-term neonatal critically ill foals which required 24-h supportive care, antibiotics and dextrose-supplemented polyionic fluids given intravenously, nasal insufflation with oxygen and nutritional supplementation. There was no association between sepsis score or survival and pharmacokinetic parameters. Concurrent hypoxia and azotaemia were associated with significantly decreased clearance and increased peak and trough serum concentrations of amikacin; however, peaks or troughs did not exceed toxic values. Derangements in serum peak, trough and clearance values, which were present on admission, persisted over the 6-day duration of this study. Daily monitoring of serum amikacin concentration revealed a tendency to underdose (particularly in foals receiving aggressive fluid therapy), which necessitated increasing the dose/kg body weight (9-12 mg/kg) and increasing the dose interval (10-12 h) in 40% (8/20) of the cases, so that blood concentrations of amikacin could be maintained within the target range of 3-15 micrograms/ml. Amikacin-induced nephrotoxicity was not indicated by conventional laboratory testing, nor was it strongly suspected after examination of post mortem lesions.

The efficacy of amoxycillin in the control of laboratory induced Aeromonas salmonicida infection in Atlantic salmon parr was investigated. When given in the diet at a dose rate of 80 mg per kg bodyweight it was effective against both a moderate and severe challenge (with mortality rates in untreated groups of 75 per cent and 45 per cent). At 40 mg per kg it was effective against the moderate challenge only. The plasma levels in these regimens were 1.25 micrograms per ml and 0.3 to 0.6 micrograms per ml and the minimum inhibitory concentration of the challenge strain of A salmonicida was 0.6 micrograms per ml. The potential of the Charm radiobioassay system in detecting antibiotic residues in fish tissue was studied. The level of amoxycillin in muscle and bone from fish in mid-treatment at 80 mg per kg was 0.32 micrograms per ml. After a 12 day withdrawal period at 18 degrees C no residue was detected within the 0.005 micrograms per ml limit of this test.

A female black rhinoceros calf developed significant hypoglycemia (blood glucose, 30 mg/dL) and hypothermia (97 degrees F) within 48 hours of birth and refused to nurse. Normal gestation of the black rhinoceros is 15 months, but elongated hoof slippers and low birth weight (30 kg) suggested prematurity in this calf. Clinical symptoms of neonatal sepsis including lassitude and poor sucking continued in spite of the aggressive use of antibiotics, and the calf required mechanical ventilatory support on day 7. Nutritional support including enteral gavage feedings (Pedialyte/4 ounces of SMA [Wyeth Ayerst] with sucraflox) had been instituted and was supplemented with total parenteral nutrition on day 5. Central venous access was obtained via a jugular cutdown. The total parenteral nutrition included appropriate electrolytes and vitamins for the neonatal calf but did not include trace elements. The use of total parenteral nutrition by our zoos for therapeutic purposes is increasing. Experience with total parenteral nutrition in exotic animals such as the black rhinoceros is limited, yet this may be an important therapeutic modality in these animals, particularly those in danger of extinction.