Evaluating the liver abscess microbiota of beef cattle during a reduction in tylosin supplementation shows differences according to abscess size and fraction.

Liver abscesses (LA) resulting from bacterial infection in cattle pose a significant global challenge to the beef and dairy industries. Economic losses from liver discounts at slaughter and reduced animal performance drive the need for effective mitigation strategies. Tylosin phosphate supplementation is widely used to reduce LA occurrence, but concerns over antimicrobial overuse emphasize the urgency to explore alternative approaches. Understanding the microbial ecology of LA is crucial to this, and we hypothesized that a reduced timeframe of tylosin delivery would alter LA microbiomes. We conducted 16S rRNA sequencing to assess severe liver abscess bacteriomes in beef cattle supplemented with in-feed tylosin. Our findings revealed that shortening tylosin supplementation did not notably alter microbial communities. Additionally, our findings highlighted the significance of sample processing methods, showing differing communities in bulk purulent material and the capsule-adhered material. Fusobacterium or Bacteroides ASVs dominated LA, alongside probable opportunistic gut pathogens and other microbes. Moreover, we suggest that liver abscess size correlates with microbial community composition. These insights contribute to our understanding of factors impacting liver abscess microbial ecology and will be valuable in identifying antibiotic alternatives. They underscore the importance of exploring varied approaches to address LA while reducing reliance on in-feed antibiotics.

Liver abscess microbiota of feedlot steers finished in natural and traditional management programs.

Liver abscess etiology in feedlot steers involves the escape of bacteria from the digestive tract to form a polymicrobial abscess within or on the external surface of the liver. However, little is known about the effects of feedlot finishing systems on the microbial composition of the liver abscess purulent material. Liver abscesses were collected at the time of harvest from steers originating from a single feedlot managed in either a traditional program (which included tylosin phosphate supplementation) or a natural program (without tylosin phosphate supplementation). The purulent material of liver abscesses from traditionally managed steers (N = 53 abscesses) and that of naturally managed steers (N = 62 abscesses) was characterized using the V4 region of the 16S rRNA gene. Two phyla and three genera were found in greater than 1% relative abundance across all abscesses. The genus Fusobacterium was identified in all liver abscess samples and accounted for 64% of sequencing reads. Bacteroides and Porphyromonas genera accounted for 33% and 1% of reads, respectively. Trueperella was more likely to be found in the liver abscesses of naturally managed steers than traditionally managed steers (P = 0.022). Over 99% of the genus-level bacterial sequences observed across all liver abscesses belonged to Gram-negative genera. Bacteria known to colonize both the rumen and hindgut were identified within liver abscesses. No differences in alpha diversity or beta diversity were detected between liver abscess communities (between the two management programs or individual pens) when tested as richness, Shannon Diversity Index, or weighted UniFrac distances (P > 0.05). These results were consistent with previous identification of Fusobacterium necrophorum as the primary bacteriologic agent within liver abscesses and emphasized the relationship between the gastrointestinal microbiota and liver abscess formation. Though the microbiota of the liver abscess purulent material was similar between steers fed an antibiotic-free diet and those fed an antibiotic-containing diet from the same feedlot, divergence was detected in liver abscess communities with some being dominated by Fusobacterium and others being dominated by Bacteroides.

As feedlot cattle consume grain, the rumen becomes more acidic. If the lining of the digestive tract is damaged, bacteria that normally remain in the digestive tract can enter the body. Certain bacteria like Fusobacterium necrophorum are involved in the formation of liver abscesses. Feedlot cattle are commonly fed an antibiotic (tylosin phosphate) to reduce the occurrence of liver abscesses, but increasing scrutiny is placed on the antibiotic use. However, the effect of eliminating the antibiotic used to prevent liver abscesses on the bacterial communities involved in liver abscess formation is unknown. This study compared the bacteria found within liver abscesses of cattle fed tylosin phosphate with that of cattle not fed tylosin phosphate. All liver abscesses contained F. necrophorum, and Bacteroides was the second most commonly identified bacterium. Trace amounts of bacteria known to colonize the mouth and digestive tract were observed. Trueperella, a bacteria targeted by tylosin phosphate, was found more frequently in liver abscesses from cattle that received no antibiotic. While the core bacterial composition of the liver abscess was unaffected by antibiotic supplementation to feedlot steers, reduced Trueperella in liver abscesses from cattle-fed tylosin phosphate could be related to a reduction in liver abscess prevalence.

Effects of iron on the growth, biofilm formation and virulence of Klebsiella pneumoniae causing liver abscess.

BACKGROUND: Klebsiella pneumoniae is considered the most clinically relevant species of Enterobacteriaceae, known to cause severe infections including liver abscesses. To the best of our knowledge, a large proportion of iron in the human body is accumulated and stored in the liver. We hypothesize that increased iron availability is an important factor driving liver abscess formation and we therefore aim to understand the effects of iron on K. pneumoniae causing liver abscesses. RESULTS: All tested K. pneumoniae clinical isolates, including those isolated from liver abscesses and other abdominal invasive infection sites, grew optimally when cultured in LB broth supplemented with 50 µM iron and exhibited the strongest biofilm formation ability under those conditions. Decreased growth and biofilm formation ability were observed in all tested strains when cultured with an iron chelator (P < 0.05). The infection model of G. mellonella larvae indicated the virulence of liver abscess-causing K. pneumoniae (2/3) cultured in LB broth with additional iron was significantly higher than those under iron-restricted conditions (P < 0.05). The relative expression levels of the four siderophore genes (iucB, iroB, irp1, entB) in K. pneumoniae strains isolated from liver abscesses cultured with additional iron were lower than those under iron-restricted conditions (P < 0.05). CONCLUSIONS: It is suggested by our research that iron in the environment can promote growth, biofilm formation and enhance virulence of K. pneumoniae causing liver abscesses. A lower expression of siderophore genes correlates with increased virulence of liver abscess-causing K. pneumoniae. Further deeper evaluation of these phenomena is warranted.

Investigation of tylosin in feed of feedlot cattle and effects on liver abscess prevalence, and fecal and soil microbiomes and resistomes1.

Liver abscesses in feedlot cattle are detrimental to animal performance and economic return. Tylosin, a macrolide antibiotic, is used to reduce prevalence of liver abscesses, though there is variable efficacy among different groups of cattle. There is an increased importance in better understanding the etiology and pathogenesis of this condition because of growing concern over antibiotic resistance and increased scrutiny regarding use of antibiotics in food animal production. The objective of this study was to compare the microbiomes and antimicrobial resistance genes (resistomes) of feces of feedlot cattle administered or not administered tylosin and in their pen soil in 3 geographical regions with differing liver abscess prevalences. Cattle (total of 2,256) from 3 geographical regions were selected for inclusion based on dietary supplementation with tylosin (yes/no). Feces and pen soil samples were collected before harvest, and liver abscesses were identified at harvest. Shotgun and 16S rRNA amplicon sequencing were used to evaluate the soil and feces. Microbiome and resistome composition of feces (as compared by UniFrac distances and Euclidian distances, respectively) did not differ (P > 0.05) among tylosin or no tylosin-administered cattle. However, feedlot location was associated with differences (P ≤ 0.05) of resistomes and microbiomes. Using LASSO, a statistical model identified both fecal and soil microbial communities as predictive of liver abscess prevalence in pens. This model explained 75% of the variation in liver abscess prevalence, though a larger sample size would be needed to increase robustness of the model. These data suggest that tylosin exposure does not have a large impact on cattle resistomes or microbiomes, but instead, location of cattle production may be a stronger driver of both the resistome and microbiome composition of feces.

Thiazolidinediones and reduced risk of incident bacterial abscess in adults with type 2 diabetes: A population-based cohort study.

AIM: Previous research has suggested that peroxisome proliferator-activated receptor-gamma (PPAR-γ) may play an important role in immunomodulation. We aimed to examine the association between thiazolidinediones, PPAR-γ agonists and incidence of bacterial abscess among patients with type 2 diabetes. MATERIALS AND METHODS: This retrospective cohort study between 2000 and 2010 included 46 986 propensity (PS)-matched patients diagnosed with type 2 diabetes. We compared the incidence of bacterial abscess, including liver and non-liver abscesses, between patients treated with metformin plus a thiazolidinedione (M + T, N = 7831) or metformin plus a sulfonylurea (M + S, N = 39 155). Data were retrieved from a population-based Taiwanese database. We applied Cox proportional hazard regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), comparing M + T and M + S after PS matching. RESULTS: During a median follow-up of 4.5 years, the incidence rate of bacterial abscess was lower with M + T than with M + S treatment (1.89 vs 3.15 per 1000 person-years) in the PS-matched cohort. M + T was associated with a reduced risk of bacterial abscess (HRs after PS matching, 0.58; 95% CI, 0.42-0.80 for total bacterial abscess; 0.54; 95% CI, 0.28-1.07 for liver abscess; 0.59; 95% CI, 0.41-0.85 for non-liver abscess). Results did not change materially after accounting for unmeasured confounding factors using high-dimenional PS matching and differential censoring between regimen groups. Rosiglitazone and pioglitazone, in combination with metformin, produced similar reductions in risk of all abscess outcomes. CONCLUSION: We found that M + T may provide a protective benefit in reducing the incidence of bacterial abscesses. These findings merit further investigation.

The Changing Paradigm of Management of Liver Abscesses in Chronic Granulomatous Disease.

Background: Chronic granulomatous disease (CGD) is a rare genetic disorder causing recurrent infections. More than one-quarter of patients develop hepatic abscesses and liver dysfunction. Recent reports suggest that disease-modifying treatment with corticosteroids is effective for these abscesses. Comparison of corticosteroid therapy to traditional invasive treatments has not been performed. Methods: Records of 268 patients with CGD treated at the National Institutes of Health from 1980 to 2014 were reviewed. Patients with liver involvement and complete records were included. We recorded residual reactive oxygen intermediate (ROI) production by neutrophils, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase germline mutation status, laboratory values, imaging characteristics, time to repeat hepatic interventions, and overall survival among 3 treatment cohorts: open liver surgery (OS), percutaneous liver-directed interventional radiology therapy (IR), and high-dose corticosteroid management (CM). Results: Eighty-eight of 268 patients with CGD suffered liver involvement. Twenty-six patients with a median follow-up of 15.5 years (8.5-32.9 years of follow-up) had complete records and underwent 100 standard interventions (42 IR and 58 OS). Eight patients received a treatment with high-dose corticosteroids only. There were no differences in NADPH genotype, size, or number of abscesses between patients treated with OS, IR, or CM. Time to repeat intervention was extended in OS compared with IR (18.8 vs 9.5 months, P = .04) and further increased in CM alone (median time to recurrence not met). Impaired macrophage and neutrophil function measured by ROI production correlated with shorter time to repeat intervention (r = 0.6, P = .0019). Conclusions: Treatment of CGD-associated liver abscesses with corticosteroids was associated with fewer subsequent hepatic interventions and improved outcome compared to invasive treatments.

ESBL E coli and P. aeruginosa Resistance to Ceftolozane-Tazobactam in a Patient with a Liver Abscess. The Search for an Omnipotent Antibiotic Goes On!

Multi drug resistant (MDR) Pseudomonas aeruginosa and Extended- Spectrum-lactamase (ESBL) Enterobacteriaceae are becoming an increasing difficult clinical problem. Immediate resistance to some of the new antimicrobials such as ceftolozane/tazobactam is unusual and is due to a variety of mechanisms such as hyper-production of inactivating enzymes and gene mutation. In addition, previous antimicrobial administration is a well-recognized risk factor to develop resistance. We present a patient with a liver abscess where the organism was resistant to ceftolozane/tazobactam resulting in a poor clinical outcome.

Lactobacillus: the not so friendly bacteria.

We present a 65-year-old diabetic patient with a complex liver abscess and bacteraemia from Lactobacillus paracasei The abscess resulted in a prolonged hospital stay due to ongoing sepsis despite ultrasound-guided drainage and broad-spectrum antibiotics. Furthermore, the patient developed several secondary complications including a right-sided pleural effusion, an inferior vena cava thrombus and septic lung emboli. The abscess was eventually managed successfully with a prolonged course of antibiotics and multiple ultrasound-guided drainage procedures.To our knowledge, this is the first reported case of probiotic consumption, confirmed by strain identification, as the likely source of a liver abscess. Probiotic products have been widely used for many years and are advocated to the general public for their health benefits with no warning of side effects. Lactobacilli are one group of bacteria commonly used in these products. Although rare, complications have been reported. Susceptible patients, such as those who are immunocompromised, should be advised against excessive consumption.

Bacterial flora of liver abscesses in crossbred beef cattle and Holstein steers fed finishing diets with or without tylosin.

Holstein steers raised for beef production consistently have a higher prevalence and more severe form of liver abscesses than cattle of beef breeds. A study was conducted to compare bacterial flora of liver abscesses collected from multiple abattoirs from 4 groups of cattle, arranged in a 2 × 2 factorial design, consisting of crossbred cattle and Holstein steers, and each group fed a finishing diet supplemented with or without tylosin. A total of 383 liver abscess samples, consisting of 94 and 81 from crossbred cattle and 89 and 119 from Holstein steers fed finishing diets with or without tylosin, respectively, were subjected for anaerobic and aerobic bacterial isolations. The minimum inhibitory concentrations (MIC) of tylosin to the predominant bacterial species were determined. The likelihood chi-square test was performed to assess unadjusted differences in bacterial prevalence proportions between the 2 types of cattle (crossbred and Holstein steers) and feed type (tylosin or no tylosin). There was no interaction between cattle type and tylosin inclusion on the prevalence of any of the bacterial species isolated. Liver abscesses from Holstein steers yielded a higher total number of isolates compared to liver abscesses from crossbred cattle (1060 vs. 788). subsp. was isolated from all abscesses. The prevalence of subsp. was 19.1% and was not affected by the cattle type or tylosin. The prevalence of was higher ( < 0.01) in crossbred cattle (73.7%) compared to Holstein steers (29.8%). Also, the prevalence of was higher in abscesses from tylosin-fed (66.1%) cattle than no tylosin-fed cattle (35%). The overall prevalence of was 25.3% and was similar ( = 0.58) between cattle type, but the prevalence was lower ( < 0.01) in tylosin-fed (16.9%) compared to no tylosin-fed group (33%). Mean MIC of tylosin for and were similar across both cattle types and tylosin inclusion. Although bacterial flora of liver abscesses from Holstein steers appeared to be more diverse than that of crossbred cattle, there was no difference in the prevalence of the and and in fact, prevalence of was higher in crossbred than Holstein steers. Therefore, the difference in bacterial flora is not the likely reason for higher prevalence and severity of liver abscesses in Holstein steers than crossbred beef cattle.

Guillaine-barre syndrome; a rare complication of melioidosis. a case report.

BACKGROUND: Melioidosis caused by Burkholderia pseudomellei is an infection with protean clinical manifestations. Guillain-Barré syndrome [GBS] associated with melioidosis is very rare. CASE PRESENTATION: A 42-year-old woman with diabetes presented with abdominal pain, vomiting and intermittent fever for one month. Six months before presentation she had recurrent skin abscesses. Three months before presentation she had multiple liver abscesses which were aspirated in a local hospital. The aspirate grew "coliforms" resistant to gentamicin and sensitive to ceftazidime. On presentation she had high fever and tender hepatomegaly. Ultra Sound Scan of abdomen showed multiple liver and splenic abscesses. Based on the suggestive history and sensitivity pattern of the previous growth melioidosis was suspected and high dose meropenem was started. Antibodies to melioidin were raised at a titre of 1:10240. The growth from the aspirate of liver abscess was confirmed as Burkholderia pseudomellei by polymerase chain reaction [PCR]. After a week of treatment, patient developed bilateral lower limb weakness. Deep tendon reflexes were absent. There was no sensory loss or bladder/bowel involvement. Analysis of the cerebro-spinal fluid showed elevated proteins with no cells. There was severe peripheral neuropathy with axonal degeneration. A diagnosis of GBS was made and she was treated with plasmapharesis with marked improvement of neurological deficit. Continuation of intravenous antibiotics lead to further clinical improvement with normalization of inflammatory markers and resolution of liver and splenic abscess. Eradication therapy with oral co-trimoxazole and co-amoxyclav was started on the seventh week. Patient was discharged to outpatient clinic with a plan to continue combination of oral antibiotics for 12 weeks. At the end of 12 weeks she was well with complete neurological resolution and no evidence of a relapse. CONCLUSIONS: Guillaine Barre syndrome is a rare complication of melioidosis and should be suspected in a patient with melioidosis who develop lower limb weakness. Plasmapharesis can be successfully used to treat GBS associated with active melioidosis.

A case of hypermucoviscous Klebsiella pneumoniae liver abscess syndrome in an Iraqi male.

A 53-year-old man presented with fevers, productive cough and decreased appetite. He emigrated from Iraq 4 years ago. Chest x-ray revealed a left lung consolidation. Respiratory cultures and two sets of blood cultures grew out pan-susceptible Klebsiella pneumoniae Liver ultrasound revealed a 6.4-cm complex lesion in the left hepatic lobe. A biopsy of the liver lesion produced bloody purulent aspirate; abscess cultures yielded a highly viscous pan-susceptible K. pneumoniae Klebsiella pneumoniae liver abscess syndrome is a newly described invasive syndrome due to a hypermucoviscous phenotype associated with serotypes K1 and K2 of Klebsiella. Although it is more commonly endemic to the Asian-Pacific region, it has been increasingly reported as an emerging global disease. We present the first case of this syndrome in a patient of middle-eastern descent. We also present pictorial evidence of the microbe's unique viscous, muculent texture grown on agar.

Liver abscess in advanced hepatocellular carcinoma after sorafenib treatment.

Hepatocellular carcinoma (HCC) is a critical global health issue and the third most common cause of cancer-related deaths worldwide. The majority of patients who present HCC are already at an advanced stage and their tumors are unresectable. Sorafenib is a multi-kinase inhibitor of the vascular endothelial growth factor pathway and was recently introduced as a therapy for advanced HCC. Furthermore, studies have shown that oral sorafenib has beneficial effects on survival. However, many patients experience diverse side effects, and some of these are severe. Liver abscess development has not been previously documented to be associated with sorafenib administration in HCC. Here, we report the case of a HCC patient that developed a liver abscess while being treated with sorafenib.

[Cholangitis with hepatic microabscesses caused by Salmonella enterica serovar choleraesuis]. / Cholangitis mit hepatischen Mikroabszessen durch Salmonella enterica Serovar Choleraesuis.

HISTORY AND ADMISSION FINDINGS: A 71-year-old man was admitted to the emergency unit of another hospital with a mild gastroenteritis and high fever. On admission g-GT and C-reactive protein (CRP) levels were markedly elevated. Under nonspecific antibiotic therapy with ampicillin/sulbactam the fever persisted and for the first time, on day 5, the patient complained of right-sided abdominal pain. An increase in the laboratory values indicated cholestasis. After changing the antibiotics to ceftriaxon and metronidazole, acute cholangitis being suspected, the fever subsided immediately and the CRP level decreased. The patient was discharged after seven days of antibiotic treatment. But he was once more admitted after four weeks to another hospital because of severely reduced general condition and mild fever. He was transferred to our unit after two weeks. INVESTIGATIONS AND DIAGNOSIS: The test values indicated cholestasis and CRP was markedly elevated, while aminotransferase activity was slightly increased and normocytic normochromic anemia developed. Viral hepatitis, autoimmune and metabolic liver diseases, toxic liver damage, extrahepatic cholestasis and an endocarditis were excluded. Bile was aspirated by endoscopic retrograde cholangiopancreatography and added to blood culture bottles. Salmonella enterica serovar choleraesuis var. Kunzendorf was isolated. TREATMENT AND FURTHER COURSE: The patient was treated with ciprofloxacin, 2 x 250 mg by mouth for a total of five weeks. After 17 days of treatment no Salmonella bacteria were grown from a newly aspirated bile sample and the patient became free of fever. CONCLUSION: Salmonella infections do not always present as gastroenteritis. Bacteremia should be considered in the differential diagnosis of such infections. If cholangitis persists, the aspiration of bile for microbiological tests can be a rational diagnostic step and facilitates treatment. Prolonged administration of antibiotics is necessary to avoid relapse. and follow-up is very important when treatment is finished.

In vivo selection of OmpK35-deficient mutant after cefuroxime therapy for primary liver abscess caused by Klebsiella pneumoniae.

OBJECTIVES: The aim of the study was to characterize the genetic basis of beta-lactam resistance developed in clinical isolates of Klebsiella pneumoniae after exposure to cefuroxime. METHODS: Clinical features of two episodes of liver abscess caused by K. pneumoniae in a diabetic patient were reported. Four isolates (KP(1)/KP(2) and KP(3)/KP(4)) of K. pneumoniae were recovered from cultures of blood/pus in the first and second episodes, respectively. Laboratory investigation of the K. pneumoniae isolates included genotyping by PFGE, resistance gene analysis by PCR amplification and DNA sequencing, and outer membrane protein analysis by SDS-PAGE. RESULTS: KP(3) and KP(4) were recovered after a 21 day cefuroxime therapy and demonstrated identical genotypes to that of KP(1) and KP(2). However, compared with KP(1) and KP(2), emerging resistance to piperacillin, cefalotin, cefuroxime and cefoxitin was observed. The other antibiotics tested, except ampicillin, retained the same effectiveness against the four isolates, although increases (4- to 8-fold) in the MICs of cefotaxime, ceftriaxone, ceftazidime, cefepime, flomoxef and aztreonam were observed in KP(3) and KP(4). None of the isolates produced extended-spectrum beta-lactamases or plasmid-mediated AmpC beta-lactamases. Deficiency in the expression of an outer membrane protein (OmpK35) was observed in the cefuroxime-resistant isolates, KP(3) and KP(4). CONCLUSIONS: The increased resistance to cephalosporins in these clinical isolates of K. pneumoniae after exposure to cefuroxime might be related to the loss of OmpK35.

The importance of Bi-Digital O-Ring Test in the treatment of multiple hepatic abscesses: a case history.

The Bi-Digital O-Ring Test has been very useful in the identification of bacterial and viral infections, as well as other etiological agents, in difficult clinical cases. Case report of a patient with multiple hepatic abscesses (pylephlebitis induced hepatic abscess is the most difficult abscess to treat), in which the etiological agent was suggested through Bi-Digital O-Ring Test with excellent clinical evolution after modification of previously ineffective multi anti-microbial treatment is presented. 45 years old, female with a history of pain at right hypochondria for 15 days, with jaundice, oscillating fever and shivering. Computerized tomography showed liver with multiples nodules in the parenchyma with additional appendicitis. An appendectomy was performed with drainage of intra abdominal abscesses. Treatment with metronidazol, ceftazidim and amicacine was performed with no improvement while the general condition of the patient was deteriorating progressively in the following 3 weeks. Bi-Digital O-Ring Test was then performed to determine the etiological agent and the drug compatibility test among effective antimicrobial agents. Based on the Bi-Digital O-Ring Test, the main etiological agent was found to be Enterobacter aerogenes. Amongst the three antibiotics that were being used, only metronidazol was effective and the other 2 was cancelled its effect. Based on Bi-Digital O-Ring Test findings two new antibiotics (cefadroxil and imipenen), were added to metronidazol and additional cilantro tablets by Hayashibara, Japan was given, and Selective Drug Uptake Enhancement Method performed, with excellent clinical, laboratory testing and tomography improvement within 10 days. Bi-Digital O-Ring Test suggested the etiological agent, and effective and mutually compatible antibiotics for treating the abscesses which resulted in a good clinical evolution, characterized by relief of fever and reduction of the hepatic abscesses in a short period and followed complete disappearance of hepatic abscess.

Bacterial flora of liver abscesses in feedlot cattle fed tylosin or no tylosin.

Bacterial flora of liver abscesses from cattle fed tylosin or no tylosin and susceptibilities of the predominant bacterial isolates to tylosin and other antimicrobial compounds were determined. Abscessed livers were collected at slaughter from cattle originating from feedlots that had fed tylosin (n = 36) or no tylosin (n = 41) for at least 2 yr, and segments of livers with one or two intact abscesses were transported to the laboratory. Abscesses were cultured for anaerobic and facultative bacteria. Fusobacterium necrophorum, either as single culture or mixed with other bacteria, was isolated from all abscesses. The incidence of subsp. necrophorum, as part of the mixed infection, was lower (P < .05) in the tylosin group than in the no-tylosin group (33 vs 61%). However, the incidence of Actinomyces pyogenes was higher (P < .01) in the tylosin group than in the no-tylosin group (53 vs 10%). Totals of 119 F. necrophorum and 21 A. pyogenes isolates were used for determinations of susceptibilities to bacitracin, oxytetracycline, chlortetracycline, lasalocid, monensin, tylosin, tilmicosin, and virginiamycin. The minimum inhibitory concentrations (MIC) of antibiotics were determined with a broth microdilution method. The mean MIC of tylosin for F. necrophorum and A. pyogenes were not different between isolates from tylosin and no-tylosin groups. We concluded that continuous feeding of tylosin did not induce resistance in F. necrophorum or A. pyogenes. Also, the higher incidence of mixed infection of F. necrophorum and A. pyogenes in liver abscesses of tylosin-fed cattle suggests a potential synergistic interaction between the two organisms in causing liver abscesses.

[A patient with generalized actinomycosis]. / Een patiënt met een gegeneraliseerde actinomycose.

A 36-year-old man was admitted because of haemoptysis and weight loss. Despite elaborate investigations, including multiple biopsies of affected organs (pleura, lung, kidney and liver) no diagnosis was established. The patient refused further diagnostic procedures and left hospital for winti treatment in Surinam. He did not take the prescribed pheneticillin and returned after seven weeks in a very poor condition. The second admission was complicated by septic shock. Despite intensive treatment he died. On autopsy actinomycosis abscesses were found in lung, liver and kidney. Even when suspected, an infection with Actinomyces is difficult to diagnose. Without adequate treatment this infection can lead to life-threatening complications.