Successful treatment of peritoneal nocardiosis caused by Nocardia paucivorans in a dog

CASE HISTORY

A 7-year-old neutered female Labrador Retriever from Hesse (Germany) was referred for evaluation of peritoneal nodular masses identified by the referring veterinarian during an investigation for a 2-month history of lethargy.

CLINICAL FINDINGS AND TREATMENT

Ultrasonographic examination of the abdomen showed multiple cavernous nodules in the intra-abdominal fat and greater omentum surrounded by free fluid. These findings were suspicious of steatitis and fatty tissue necrosis in the cranial abdomen. Cytologic and microbiological analysis of fine-needle aspirates of the fatty tissue and abdominal fluid revealed septic pyogranulomatous inflammation caused by Nocardia paucivorans. The septic abdomen indicated surgical management was appropriate and a celiotomy was performed, which revealed an inflammed mass attached by fibrous tissue to the spleen, stomach and liver. All abnormal tissue including parts of the greater omentum and the spleen, were removed and samples taken for histopathology and microbial culture. Following surgery, the dog was treated with amoxicillin/clavulanic acid. After initially improving, the dog's condition deteriorated 3 months later. Based on ultrasonographic and cytologic findings, and bacterial culture, recurrence of peritoneal nocardiosis was confirmed. In a second celiotomy, multiple inflammatory mass lesions inflammed masses in the remaining greater omentum were removed. After surgery, antimicrobial therapy was changed to trimethoprim/sulfamethoxazole for a 10-month period. No recurrence of clinical signs was reported 6, 12 and 27 months after the initial surgery.

DIAGNOSIS

Peritonitis caused by Nocardia paucivorans.

CLINICAL RELEVANCE

To our knowledge, this is the first published report of canine infection with Nocardia paucivorans and the first case of peritoneal nocardiosis successfully treated in a dog. This report indicates that reducing the microbial burden by surgical debridement of affected tissues and peritoneal lavage followed by long-term treatment with a suitable antimicrobial may be an effective treatment for peritoneal nocardiosis in dogs.

Development of a hierarchical typing approach for Mycobacterium avium subsp. paratuberculosis (MAP) and characterization of MAP field cultures from Central Germany

AIMS

Development of a novel hierarchical Mycobacterium avium subsp. paratuberculosis (MAP) typing approach and characterization of MAP field cultures in Central Germany.

METHODS AND RESULTS

By combining single nucleotide polymorphisms (SNPs) and mycobacterial interspersed repetitive unit-variable number tandem repeat, we developed a highly discriminating and phylogenetically accurate hierarchical MAP typing approach. Moreover, a novel stepwise workflow was employed to reduce the number of SNP reactions required making the typing approach more affordable. MAP field cultures (n = 142) from dairy herds in Central Germany were classified as cattle type and showed a high level of heterogeneity. Intra-herd multiple genotypes were evident in (13-25%) of the investigated herds.

CONCLUSIONS

The hierarchical MAP typing approach proved to be useful in fine discrimination between MAP cultures within limited geographical regions. This could potentially be used in unravelling MAP transmission chains in the respective regions. The observed heterogeneity in some herds is assumed to be due to either multiple introductions through inter-herd trade or intra-herd evolution over time.

SIGNIFICANCE AND IMPACT OF THE STUDY

Future MAP epidemiological studies will benefit from the advantages of the novel hierarchical typing approach. The SNP number reduction approach employed here could be extrapolated for other analogous pathogens.

Intestinal displacements in older harbour and grey seals

Intestinal displacements including volvulus, torsion and invagination have been reported in various terrestrial and marine mammals. We conducted pathological investigations on 157 seals that had either stranded on the coasts of the North or Baltic Sea between 1996 and 2015 (115 harbour seals, >19 mo old; 21 grey seals, >13 mo old) or died while in human care (18 harbour seals, >19 mo old; 3 grey seals, >13 mo old). Intestinal displacements were found in 23% of the examined free-living harbour seals, in 5% of the stranded grey seals and in 17% of the harbour seals in human care. Intestinal volvulus, found in 24 cases, was characterized by twisting of the intestine along the mesenteric axis (180-540°) resulting in vascular obstruction and haemorrhagic infarction. In harbour seals, the sex ratio of individuals suffering from volvulus tended to be biased towards females during April to June, suggesting an elevated risk for pregnant females around birth time. Invagination was detected in 11 cases, 5 of which suffered from additional volvulus. Pathological findings associated with intestinal volvulus and invagination were sero-haemorrhagic effusions in the abdominal cavity. Enteritis, parasitic infection with gastric nematodes and intestinal acanthocephalans and bacterial infection with predominantly Clostridium perfringens and Escherichia coli were observed in most of the affected animals. In total, 30 investigated harbour and grey seals suffered from intestinal displacements. Pregnant females seemed to be more vulnerable around birth time. Causes of intestinal displacements remain undetermined, but are likely multifactorial.

Occurrence of anthropozoonotic parasitic infections and faecal microbes in free-ranging sperm whales (Physeter macrocephalus) from the Mediterranean Sea

Sperm whales (Physeter macrocephalus) are the largest toothed whales and only living member of family Physeteridae. Present survey represents first report on cultivable faecal microbes and gastrointestinal helminths and protozoans infecting free-ranging sperm whales inhabiting Mediterranean Sea waters surrounding Balearic Archipelago, Spain. Twenty-five individual sperm whale scat samples, including one calf, were collected without disturbance of animals during the summer of 2016. Parasitological diagnostic methods, such as sodium acetate acetic formalin (SAF) method, carbol fuchsin-stained faecal smears, Giardia/Cryptosporidium coproantigen ELISAs and an Anisakis-specific PCR were applied for further identification. Five bacterial genera, i.e. Acinetobacter, Clostridium, Enterococcus, Staphylococcus and Streptococcus, and one fungus namely Cladosporium were identified. Parasitological infections included seven different parasite species with some of them bearing anthropozoonotic potential. Thus, four of these parasites were zoonotic, i.e. Anisakis, Balantidium, Diphyllobothriidae gen. sp. and Giardia. Additionally, Zalophotrema curilensis eggs, spirurid-like eggs and Cystoisospora-like oocysts were identified. Molecular characterization identified Anisakis physeteris as the species infecting these whales. This survey provides first records on occurrence of two zoonotic enteropathogenic protozoan parasites (Giardia and Balantidium) and of facultative pathogenic bacteria (Clostridium and Enterococcus) in sperm whales. Presented data should be considered as a baseline study for future monitoring surveys on anthropozoonotic pathogens affecting free-living sperm whale populations and enhance investigations on possible impact on public health as well as on isolated Mediterranean sperm whale subpopulation.

Lactococcus lactis, causative agent of an endocarditis valvularis and parietalis thromboticans in the allis shad, Alosa alosa (L.)

Since the 1940s, the anadromous allis shad, Alosa alosa (L.), has suffered population declines throughout its distribution range in Europe. In context of EU-LIFE projects for the reintroduction of the allis shad in the Rhine system, a comprehensive study was started in 2012 to investigate infectious diseases occurring in allis shad. In course of the study, 217 mature and young-of-the-year allis shad originating from the wild population from the Gironde-Garonne-Dordogne system (GGD-system) and the Rhine system as well as 38 allis shad from the breeding population were examined by use of bacteriological and histological methods. In 2012 and 2014, an endocarditis valvularis thromboticans caused by a coccoid bacterium was detected in 16% and 25% of mature allis shad originating from the GGD-system. Results of microbiologic examinations, including biochemical characteristics, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence analysis, revealed Lactococcus lactis as causative agent of this infection. This is the first report of an endocarditis valvularis and parietalis thromboticans caused by Lactococcus lactis in fish. Possible sources of infection as well as the impact for the reintroduction programme are discussed.

Determinants for persistence of Pseudomonas aeruginosa in hospitals: interplay between resistance, virulence and biofilm formation

Pseudomonas aeruginosa (Pa) is one of the major bacterial pathogens causing nosocomial infections. During the past few decades, multidrug-resistant (MDR) and extensively drug-resistant (XDR) lineages of Pa have emerged in hospital settings with increasing numbers. However, it remains unclear which determinants of Pa facilitated this spread. A total of 211 clinical XDR and 38 susceptible clinical Pa isolates (nonXDR), as well as 47 environmental isolates (EI), were collected at the Heidelberg University Hospital. We used RAPD PCR to identify genetic clusters. Carriage of carbapenamases (CPM) and virulence genes were analyzed by PCR, biofilm formation capacity was assessed, in vitro fitness was evaluated using competitive growth assays, and interaction with the host's immune system was analyzed using serum killing and neutrophil killing assays. XDR isolates showed significantly elevated biofilm formation (p < 0.05) and higher competitive fitness compared to nonXDR and EI isolates. Thirty percent (62/205) of the XDR isolates carried a CPM. Similarities in distribution of virulence factors, as well as biofilm formation properties, between CPM+ Pa isolates and EI and between CPM- and nonXDR isolates were detected. Molecular typing revealed two distinct genetic clusters within the XDR population, which were characterized by even higher biofilm formation. In contrast, XDR isolates were more susceptible to the immune response than nonXDR isolates. Our study provides evidence that the ability to form biofilms is an outstanding determinant for persistence and endemic spread of Pa in the hospital setting.

A colibacillosis outbreak in farmed red-legged partridges (Alectoris rufa)

Colibacillosis in different forms is responsible for significant economic losses in the poultry industry worldwide. Escherichia coli strains frequently implicated in poultry disease are designated as avian pathogenic E. coli (APEC). Natural infections and disease due to APEC have been described in wild birds, but not as yet in red-legged partridges. During an outbreak in an experimental partridge farm, 23 of 43 1-day-old chicks belonging to the same batch died. Putative APEC strains were detected and isolated both in cloacal swabs and in tissues originating from the same individuals and from different birds showing similar clinical signs. This is the first study that identifies APEC strains linked to a colibacillosis outbreak in farmed red-legged partridges, and also confirms the importance of farmed partridges as fecal carriers and potential spreaders of APEC.

Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective

The possible zoonotic spread of antimicrobial-resistant bacteria is controversial. This review discusses global molecular epidemiological data combining both analyses of the chromosomal background, using multilocus sequence typing (MLST), and analyses of plasmid (episomal) extended-spectrum β-lactamase (ESBL)/AmpC genes in Escherichia coli present in humans and animals. For consideration of major epidemiological differences, animals were separated into livestock and companion animals. MLST revealed the existence of ESBL-producing isolates thoughout the E. coli population, with no obvious association with any ancestral EcoR group. A similar distribution of major ESBL/AmpC types was apparent only in human isolates, regardless of their geographical origin from Europe, Asia, or the Americas, whereas in animals this varied extensively between animal groups and across different geographical areas. In contrast to the diversity of episomal ESBL/AmpC types, isolates from human and animals mainly shared identical sequence types (STs), suggesting transmission or parallel micro-evolution. In conclusion, the opinion that animal ESBL-producing E. coli is a major source of human infections is oversimplified, and neglects a highly complex scenario.

Examining an outlier: molecular diversity in the cirripedia

Despite the typical assumption in studies of mitochondrial diversity that such data are useful for approximating population size and demography, studies of sequence diversity in mitochondrial DNA across the Metazoa have shown a surprising excess of rare alleles, a pattern associated either with strong selection or population growth. Previous work has shown that this bias toward an excess of rare alleles is typical across the Crustacea, and in particular, in the Cirripedia (barnacles). Here, we directly evaluate sequence data from studies of barnacle populations to ensure that inclusion of cryptic species is not the cause of this pattern. The results shown here reinforce previous studies that suggest caution in interpreting such patterns of allele frequencies, as they are likely to be influenced both by demographic changes and selection.

Impact of Escherichia coli vaccine on parent stock mortality, first week mortality of broilers and population diversity of E. coli in vaccinated flocks

In the present investigation 20,000 broiler parents were vaccinated during rearing with Nobilis Escherichia coli vaccine and were placed in two out of four identical houses, with the remaining two houses on the same farm accommodating 20,000 unvaccinated control birds. During the production period a total of 335 dead birds (including 171 vaccinated and 164 control birds) randomly selected from the four houses were subjected to post-mortem examination. Although the overall mortality between the vaccinated and control flocks did not differ, mortality due to E. coli infections made up only 8.2% in vaccinated birds compared with 24.6% in unvaccinated birds. All E. coli isolates recovered from internal organs were assigned to the same phylogenetic group (B2), but a major genetic diversity was outlined by multilocus sequence typing. Only a single isolate was demonstrated to harbour a gene encoding the P-fimbriae variant F11, a key component of the Nobilis vaccine. Significant differences in average first week mortality, calculated average weight at 38 days and food conversion rate among broiler flocks originating from vaccinated and control birds, respectively, were not found. Further investigations are needed to explain the protection observed and the impact on the genetic diversity of E. coli.

Ciprofloxacin compared with doxycycline for nongonococcal urethritis. Ineffectiveness against Chlamydia trachomatis due to relapsing infection

We compared 7-day regimens of ciprofloxacin in dosages of 750 and 1000 mg twice daily with doxycycline 100 mg twice daily for the treatment of nongonococcal urethritis in 178 men enrolled in a prospective, randomized, double-blind trial. The overall clinical response was comparable in the three treatment groups at both 2 and 4 weeks after therapy. However, among patients who initially had cultures positive for chlamydia, Chlamydia trachomatis was reisolated within 4 weeks after treatment in none of 10 doxycycline-treated patients, in 11 (52%) of 21 patients treated with 750 mg of ciprofloxacin twice daily, and in six (38%) of 16 patients treated with 1000 mg of ciprofloxacin twice daily. Each of the recurrent strains was identical in serotype to the original infecting strain. We conclude that ciprofloxacin in dosages as high as 2 g daily is inadequate for treatment of chlamydial urethritis in men, often resulting in relapsing infections.

[Epidemiology and clinical aspects of non-A, non-B hepatitis (author's transl)]

Among 288 patients with acute viral hepatitis investigated between 1970 and 1976 29 (10%) had non-A, non-B hepatitis. In 9 of these 29 patients posttransfusion hepatitis was proven, the remaining 20 patients had sporadic infections. The incubation period of posttransfusion hepatitis was 2--8 weeks in 7 patients and 12 and 16 weeks in the two other patients. Transaminases changed monophasically in 22 patients, bi- or multiphasic in 7. The disease took a subicteric course in a quarter of all cases. Out of the 29 patients 17 were followed up for 2 to 7 years, one or more recurrence occurred in 9 patients, usually within the first two years after onset of the disease. Five of these 9 patients had a biphasic rise of transaminases during the acute stage. The almost complete absence of autoantibodies in the course of the acute phase might be evidence of increased suppressor cell activity favouring a chronic course. Non-organ-specific autoantibodies were only rarely observed and were completely absent in patients with posttransfusion hepatitis.