Detection of multidrug-resistant bacteria in the nasal cavities and evaluation of sinus disorders in patients undergoing Le Fort I osteotomy

INTRODUCTION

Orthognathic surgery can lead to sinus alterations, including sinusitis, attributed to the exposure of maxillary sinuses during Le Fort I osteotomy. Furthermore, being a hospital-based procedure, there is potential risk of complications arising from bacteria prevalent in such environments. This study evaluated maxillary sinusitis occurrence and the presence of multidrug-resistant bacteria in the nasal cavity before and after orthognathic surgery.

METHODS

Ten patients with dentofacial deformities underwent Le Fort I osteotomy. Clinical evaluations using SNOT-22 questionnaire were performed, and nasal cavity samples were collected pre-surgery and 3-6 months post-surgery to quantify total mesophilic bacteria and detect Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. Cone Beam Computed Tomography (CBCT) was performed pre- and post-operatively, and the results were evaluated using the Lund-Mackay system. This study was registered and approved by the Research Ethics Committee of PUCRS (No. 4.683.066).

RESULTS

The evaluation of SNOT-22 revealed that five patients showed an improvement in symptoms, while two remained in the same range of interpretation. One patient developed post-operative maxillary sinusitis, which was not detected at the time of evaluation by SNOT-22 or CBCT. CBCT showed a worsening sinus condition in three patients, two of whom had a significant increase in total bacteria count in their nasal cavities. The Brodsky scale was used to assess hypertrophy in palatine tonsils, where 60% of the subjects had grade 1 tonsils, 20% had grade 2 and 20% had grade 3. None of the patients had grade 4 tonsils, which would indicate more than 75% obstruction. Two patients harboured S. aureus and K. pneumoniae in their nasal cavities. Notably, K. pneumoniae, which was multidrug-resistant, was present in the nasal cavity of patients even before surgery, but this did not result in maxillary sinusitis, likely due to the patients' young and healthy condition.

CONCLUSION

There was an improvement in signs and symptoms of maxillary sinusitis and quality of life in most patients after orthognathic surgery. However, some patients may still harbour multidrug-resistant bacteria, even if they are asymptomatic. Therefore, a thorough pre-operative assessment is essential to avoid difficult-to-treat post-operative complications.

Characterization of Aeromonas Isolates from Ornamental Fish: Species, Virulence Genes, and Antimicrobial Susceptibility

This study aimed to characterize 300 Aeromonas spp. strains isolated from 123 ornamental fish of 32 different species presenting with septicemia, skin lesions, and/or eye lesions. Within the 300 strains, 53.0% were identified as A. veronii, 41.3% as A. hydrophila, and 5.7% as A. caviae. Among the six virulence genes investigated, the most frequent were act (90.3%) and aer (79.3%). More than 50% of A. hydrophila strains were positive for all the studied genes. A total of 30 virulence profiles were identified, with the five main profiles identified comprising 75% of strains. Only five strains were negative for all genes and were identified as A. caviae and A. veronii. The antimicrobial susceptibility profile was performed for 234 strains, with sulfonamides presenting more than 50% of the resistance rates. Susceptibility was observed mainly for cephalosporins, aminoglycosides, chloramphenicol and piperacillin-tazobactam. Multidrug resistance was detected in 82.5% of the studied strains, including A. caviae with 100% multidrug resistance, and A. hydrophila with 90.9% multidrug resistance. The SE-AFLP analysis resulted in 66 genotypes of A. hydrophila, 118 genotypes of A. veronii, and 14 genotypes of A. caviae, demonstrating the greater heterogeneity of A. veronii and A. caviae. However, no direct correlation was observed between the genotypes and the strains' origins or virulence and resistance profiles.

Evaluation of clinical and subclinical endometritis impacts on the reproductive performance and milk production of dairy cows in Brazilian herds

Clinical endometritis (CE) and subclinical endometritis (SE) are two of the main uterine diseases in dairy cows during the puerperium period that can directly affect milk production and fertility in dairy herds. The first objective of this study was to investigate the effects of the CE and SE on the subsequent reproductive performance and milk production of dairy cows in Brazilian herds, and the second objective was to evaluate the reproductive performance and milk production of dairy cows according to the positive or negative isolation of bacteria in the uterine environment. A total of 279 lactating Holstein dairy cows (28-33 days in milk) from six commercial farms were studied. These were classified into three groups: healthy cows (without CE and SE, n = 161), cows with CE (vaginal discharge score = 3 and ≥18% PMNL, n = 83) and cows with SE (absence of signs of CE and >18% PMNL, n = 35). According to the presence of bacteria isolated from the uterine environment, the animals were classified as healthy cows (n = 161), CE cows with positive (n = 68) and negative (n = 15) bacterial isolation; and SE cows with positive (n = 21) and negative (n = 14) bacterial isolation. Cows with CE (20.5%) and SE (31.4%) had a lower (p < .05) conception rate at first AI than healthy cows (47.8%). Furthermore, both cows with CE (3.1) and SE (2.8) needed more service to become pregnant than healthy cows (1.7) and more days to be pregnant (50.3 days in CE and 43.1 days in SE than healthy group; p < .001). Cows with CE (23.8 kg) and SE (23.7 kg) produced less milk than healthy cows on the day of sampling (28.2 kg); however, milk production during 305 DIM of cows with CE and SE was not impaired when compared to healthy cows. The logistic regression showed that parity, body condition score, 305 days milk production, last calving (eutocia or dystocia), twin birth and stillbirth were not associated with the incidence of CE and SE. In addition, we highlight that cows with CE and SE, but with negative bacteria isolation, did not have reproductive performance and milk production impaired during the postpartum period. These results support that the use of antibiotics would not be beneficial in these cows, contributing to the strategic and rational use of antibiotic therapy on dairy farms.

Bacterial killing activity and lysozymes: A stable defence mechanism in stallion seminal plasma?

During insemination, bacterial contamination of the ejaculate can lead to reduced sperm quality and transmission of pathogens to the female, thus should be avoided. The semen of a variety of animal taxa possess antimicrobial properties against a wide range of bacterial species through antimicrobial molecules, such as lysozyme, but their variance and the factors influencing it are unknown for most species. In this study, the antibacterial defence (bacterial killing activity (BKA) against Escherichia (E.) coli and Staphylococcus (S.) aureus as well as lysozyme concentration) was studied in seminal fluid from two consecutive ejaculates of 18 stallions. All ejaculates showed BKA against the tested bacteria, which correlated between the two consecutive ejaculates (r_S  = 0.526, p = .025 for E. coli and r_S  = 0.656, p = .003 for S. aureus) and appeared to be stable over the tested period. The lysozyme concentration (LC) showed no significant correlation between the consecutive ejaculates (r_S  = 0.161, p = .681). However, LC had a positive correlation to the ratio of apoptotic spermatozoa within the ejaculates (r_S  = 0.426, p = .019). In contrast to other livestock (e.g., boar, bull), the BKA in stallion semen did not correlate significantly with the age of the animal nor sperm quality characteristics.

Antimicrobial Resistance and Virulence Factors of Proteus mirabilis Isolated from Dog with Chronic Otitis Externa

Otitis externa is among the most prevalent diseases in dogs. If the underlying cause is not addressed, bacterial reinfection becomes frequent, necessitating antibiotic administration for an extended period of time. Prolonged treatment promotes the emergence of antibiotic-resistant bacteria and increases the risk of their transmission from animals to humans. This study aimed to analyze the antibiotic resistance pattern of the emerging pathogen Proteus mirabilis to identify bacterial virulence and antibiotic selection. Samples were collected from randomly encountered dogs with chronic otitis externa. Thirty-two strains of P. mirabilis were isolated and identified, using MALDI-TOF. The Kirby-Bauer disk diffusion method was used to assess the antibiotic susceptibility of P. mirabilis to 11 antibiotics. The isolates (n = 32) were most resistant to cefazolin (75%), trimethoprim–sulfamethoxazole (72%), chloramphenicol (72%), amoxicillin–clavulanate (63%), ampicillin (59%), cefepime (56%), ciprofloxacin (53%), aztreonam (50%), ceftazidime avibactam (50%), gentamicin (22%), and amikacin (16%). Moreover, 75% of isolates were found to be multidrug-resistant bacteria. P. mirabilis was found to have a high resistance-pattern ratio. Although the exact cause is unknown, continuous antibiotic use is thought to be a major factor. We concluded that antibiotic use must be prudent and selective to prevent antibiotic resistance.

Causes of Sow Mortality and Risks to Post-Mortem Findings in a Brazilian Intensive Swine Production System

The present study was conducted to investigate the risk factors for post-mortem findings and causes of sow mortality. A post-mortem examination and microbiological investigation were conducted on 123 sows from a breeding herd with 15,000 dams. The mortality of spontaneous death in sows occurred mostly in the peripartum period (53%; p < 0.05). The spontaneous deaths were associated with heart failures, hemorrhagic and perforating gastric ulcers, and liver torsion, while in the euthanized sows, the post-mortem findings were associated with locomotor disorders. A higher body condition score (BCS ≥ 3.5) increased (p < 0.05) heart failure on the post-mortem examination. The excessive use of manual obstetric interventions increased sow deaths resulting from cervix/uterus ruptures and increased the odds of death (p < 0.05) due to metritis. Sow mortality had a multifactorial etiology. Infections were polymicrobial. The main microbial agents identified from a septic lesion in locomotor, genitourinary, and respiratory systems were Trueperella pyogenes, Escherichia coli, and Actinobacillus pleuropneumoniae, respectively. In conclusion, sow mortality involved multiple risk factors and several bacterial agents. These results indicate that better management practices can reduce sow mortality in swine production and increase sow welfare.

Vaginal microbiota signatures in healthy and purulent vulvar discharge sows

Purulent vulvar discharges, primarily caused by genito-urinary tract infections, are an important source of economic loss for swine producers due to sow culling and mortality. However, the agents that compose the vaginal microbiota of sows and their changes during infections are not well understood. The first goal of this study was to characterize and compare the vaginal bacterial content of healthy (HE, n = 40) and purulent vulvar discharge sows (VD, n = 270) by a culture-dependent method and MALDI-TOF MS identification. Secondly, we performed 16S rRNA targeted metagenomic approach (n = 72) to compare the vaginal microbiota between these groups. We found a wide variety of bacteria, with Proteobacteria, Firmicutes, and Bacteroidota being the most abundant phyla in both groups, as well as Escherichia-Shigella, Streptococcus, and Bacteroides at the genus level. Most agents identified in the sequencing method also grew in the culture-dependent method, showing the viability of these bacteria. Alpha diversity did not differ between HE and VD sows, regarding sample richness and diversity, but a beta-diversity index showed a different microbiota composition between these groups in two tested herds. ANCOM analysis revealed that Bacteroides pyogenes were more abundant in VD females and can be a marker for this group. Other agents also require attention, such as the Streptococcus dysgalactiae and Staphylococcus hyicus found in remarkably greater relative abundance in VD sows. Network analysis revealed important positive correlations between some potentially pathogenic genera, such as between Escherichia-Shigella, Trueperella, Streptococcus, Corynebacterium, and Prevotella, which did not occur in healthy sows. We conclude that the alteration of the vaginal microbiota between healthy and purulent vulvar discharge sows, although not extreme, could be due to the increase in the relative abundance of specific agents and to associations between potentially pathogenic bacteria.

Characterization of Salmonella enterica Contamination in Pork and Poultry Meat from São Paulo/Brazil: Serotypes, Genotypes and Antimicrobial Resistance Profiles

Salmonellosis is a zoonosis of major relevance to global public health. Here we present the assessment of Salmonella enterica contamination in pork and poultry meat sold at retail markets in São Paulo, Brazil. A total of 780 meat samples (386 poultry meat and 394 pork samples) were collected from 132 markets. From these, 57 samples (7.3%) were positive for S. enterica isolation, including 32 (8.3%) poultry meat and 25 (6.3%) pork samples. S. enterica isolates were further characterized for serotyping, antimicrobial resistance and genotyping by amplified fragment length polymorphism and pulsed field gel electrophoresis. Antimicrobial resistance analysis demonstrated two main profiles: pork isolates were more resistant to macrolides, β-lactams, tetracycline, phenicols, and fluoroquinolones, and poultry meat isolates presented higher resistance to fluoroquinolones, sulfonamides, tetracycline, and β-lactams. A total of 72.4% of poultry meat isolates were identified as S. Heidelberg, while most of pork isolates were S. Typhimurium (31.7%) and S. Give (16.7%). Genotyping resulted in most clusters consisting exclusively of pork or poultry meat, no cross-contamination was detected, and a tendency to differentiate isolates according to their serotypes and markets of origin. High resistance rates to critically important antimicrobials reinforce the importance of controlling Salmonella contamination in meat production chains.

Trueperella bernardiae bloodstream infection following onco-gynaecologic surgery and literature review

Trueperella bernardiae is a Gram-positive commensal bacillus of the human skin and oropharynx. It is known as an opportunistic human pathogen causing surgical wound, skin, and soft tissue, osteoarticular, and bloodstream infections (BSIs) with severe complications. We report a case of surgical wound related T. bernardiae BSI following onco-gynaecologic surgery together with a comprehensive literature review of T. bernardiae infections to alert clinicians about this emerging pathogen.

Neobenedenia melleni from reef ornamental fish species in a retailer of Southeastern Brazil and its possible role as a mechanical vector of bacterial infection

Annually, more than 2500 ornamental fish species are traded worldwide. Forty percent of these are from marine water. Some 98% of marine species are wild-caught from their natural habitat, and the majority subsequently exported. Wild fish frequently carry pathogens, which could induce diseases after the stress of capture. Neobenedenia melleni is a platyhelminth that mainly attaches to the skin and eyes of the host. It provokes dermal inflammation, epidermal loss, skin depigmentation, reduction in the number of mucous cells, and, consequently, decreased mucus protection, and declining immunological barriers. This makes fish susceptible to secondary infections. A total of 47 wild reef fish from a retailer were examined, suspected to be infected with ectoparasites. The morphological identification revealed N. melleni as a monogenean agent. One monogenean specimen was collected from the eye of each of the 40 fish analyzed to evaluate possible bacterial secondary infections using the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technique. The MALDI-TOF MS identified that 59% of monogenean collected from the eyes had bacteria, including some pathogenic to fish. This led us to believe that the ectoparasite can be a possible mechanical vector of pathogenic bacteria for fish culture and maintenance. The use of praziquantel as an antiparasitic agent is also discussed.

Assessment of the main pathogens associated with clinical and subclinical endometritis in cows by culture and MALDI-TOF mass spectrometry identification

Clinical endometritis (CE) and subclinical endometritis (SCE) are diseases that affect dairy cows during the puerperium, causing negative effects on the animals' milk production and fertility. The objective of this study was to assess the main bacteria related to cases of CE and SCE from uterine samples of dairy cows in Brazilian herds. Selective and differential media were used for isolation of aerobic and anaerobic bacteria and further MALDI-TOF mass spectrometry (MS) identification. A total of 279 lactating dairy cows with 28 to 33 d in milk from 6 commercial farms were evaluated. Initially, cows were classified in 3 groups: cytologic healthy cows (n = 161), cows with CE (n = 83), and cows with SCE (n = 35). Healthy animals presented 97 species, followed by the CE group with 53 identified species, and SCE cows presented only 21 bacterial species. We found a significantly higher isolation rate of Trueperella pyogenes in CE (26.5%) cows compared with healthy and SCE cows. Some anaerobic species were exclusively isolated from the CE group, even though they presented lower frequency. Interestingly, 18.1% of samples from CE cows and 40% of SCE cows were negative to bacterial isolation. Despite the use of culture-dependent methods instead of molecular methods, the present study enabled the identification of a complex community of 127 different species from 48 genera, composed of aerobic and anaerobic bacterial species among the 3 different animal groups. The method of sample collection, culture, and identification by MALDI-TOF MS were essential for the success of the analyses.

Quality of dialysis water and dialysate in hemodialysis centers: highlight for occurrence of non-fermenting gram-negative bacilli

AIMS

To evaluate the physicochemical and microbiological quality of dialysis water and dialysate samples from hemodialysis centers.

METHODS AND RESULTS

Samples were fortnightly collected from three hemodialysis centers in Bauru City, Brazil, between July/2017 and June/2018, at the stages of post-reverse osmosis, reuse and dialysate. Analyses included determination of conductivity, fluoride, nitrate and sulfate; test for total coliform bacteria; count of heterotrophic bacteria; count and identification of non-fermenting gram-negative bacilli (NFGNB); drug susceptibility test; biofilm formation capacity, and genetic similarity among some isolated NFGNB. Of the analyzed samples, only 4/72 (5.6%) had conductivity values ≥ 10 mS/cm, 4/216 (1.9%) presented total coliforms, and 1/216 (0.5%) had heterotrophic bacteria count > 100 CFU/mL. NFGNB were isolated from 99/216 (45.8%) samples, and the major identified microorganisms included Herbaspirillum aquaticum/huttiense, Brevundimonas aurantiaca, Cupriavidus metallidurans, Pseudomonas aeruginosa and Ralstonia insidiosa. Isolates of P. aeruginosa and Burkholderia cepacia complex were sensitive to most antimicrobials and, together with isolates of Ralstonia insidiosa and Ralstonia pickettii, showed strong biofilm formation capacity. Some isolates expressed the same electrophoretic profile on pulsed-field gel electrophoresis, indicating persistence of bacterial clones in the systems over time.

CONCLUSIONS

NFGNB were observed in several dialysis water and dialysate samples from all investigated centers, which may represent a risk to the health of patients.

SIGNIFICANCE AND IMPACT OF THE STUDY

Regular inclusion of actions for NFGNB control and monitoring in hemodialysis fluids are suggested for greater safety of the dialytic process.

Identification of Trueperella bernardiae isolated from peking ducks (Anas platyrhynchos domesticus) by phenotypical and genotypical investigations and by a newly developed loop-mediated isothermal amplification (LAMP) assay

Trueperella (T.) bernardiae is a well-known bacterial pathogen in infections of humans, rarely in animals. In the present study, five T. bernardiae isolates, isolated from five Peking ducks of four different farms, were identified by phenotypic properties, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and genotypically by sequencing the 16S ribosomal RNA (rRNA) gene, the superoxide dismutase A encoding gene sodA, and the glyceraldehyde-3-phosphate dehydrogenase encoding gene gap. In addition, the T. bernardiae isolates could be identified with a newly developed loop-mediated isothermal amplification (LAMP) assay based on the gyrase encoding housekeeping gene gyrA. All these tests clearly identified the T. bernardiae isolates to the species level. However, the detection of the specific gene gyrA with the newly designed LAMP assay appeared with a high sensitivity and specificity, and could help to identify this bacterial species in human and animal infections in future. The importance of the T. bernardiae isolates for the clinical condition of the ducks and for the problems at farm level remains unclear.

Clinical endometritis with Trueperella pyogenes reduces reproductive performance and milk production in dairy cows

The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms.

A case of prosthetic hip infection and abscess caused by Trueperella bernardiae

Trueperella bernardiae is a skin flora organism with few reported cases of pathology. Most cases have been described in urinary tract infections and skin and soft-tissue infections. We present the first known case of T. bernardiae as a causative agent of a prosthetic hip infection with subsequent hip abscess.

Characteristics of Aerococcus viridans isolated from porcine fetuses in Korean farms

Swine abortion caused by viruses as well as bacteria has caused many economic losses in domestic farms over the years; however, bacterial abortion has not yet been studied in Korea. Several bacterial species were isolated from aborted fetuses (n = 103) for which the cause of death was not viral abortion. Among them, we focused on Aerococcus viridans, which had the highest positive rate within three provinces (Gangwon, Jeonnam and Gyeongnam). A total of 16 isolates were identified as A. viridans by matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF MS), and 13 were characterized by both antibiotic resistance and 16S rRNA gene analysis. Based on antibiotic susceptibility testing result, eight antimicrobials could not effectively eliminate the present isolation (more than 40% of isolates can resist these antibiotics), while all except two strains were susceptible to trimethoprim/sulfamethoxazole. Molecular analysis indicated genetic variation among these strains. This study is the first report detecting A. viridans from aborted fetuses in Korean domestic farms.

Silent mutations in ribosomal protein genes are associated with high-risk clones of carbapenem-resistant Acinetobacter baumannii prevalent in Brazil

OBJECTIVES

To analyze the relationship of ribosomal protein mutations and clonality of high-risk clones Acinetobacter baumannii.

METHODS

Seventy-nine carbapenem-resistant A. baumannii were subjected to whole-genome sequencing (Illumina NextSeq), and codifying sequences of ribosomal proteins were extracted and screened for mutations. MALDI-TOF MS analysis (Bruker Biotyper) and Spectra data from MALDI-TOF was employed to generate a dendrogram based on principal component analysis (PCA) data. Clones were identified by Multilocus sequencing typing (MLST) based on WGS.

RESULTS

Ribosomal RNA protein sequences extracted from the genomes identified mutations that were associated with clonal complexes, but most of them were silent. PCA did not cluster the isolates according to their clonality identified by MLST.

CONCLUSIONS

By comparing the nucleotide and amino acid sequences of diversified A. baumannii, and Bruker Biotyper profiles, we showed that silent mutations in ribosomal RNA nucleotides are associated with clonal complexes, but since most of the mutations were silent, MALDI-TOF MS raw data was not a useful tool for typing the high-risk clones of this species.

Main bacterial species causing clinical disease in ornamental freshwater fish in Brazil

Bacterial diseases are common in ornamental fish, more frequently associated with ubiquitous bacteria from the aquarium environment. The disease can lead to fish mortality and cause high economic losses if not rapidly controlled. The aim of this study was to identify the main causative bacterial agents of infection in ornamental fish with different clinical signs. A total of 126 freshwater fish, from 12 families and 38 species, with clinical signs were collected in a wholesaler in São Paulo, SP, Brazil. Samples were taken from the eye, skin ulcers, kidneys, and gills, plated on MacConkey, CHROMagar Orientation, and blood agar and incubated under aerobic and anaerobic conditions. Bacterial identification was performed by MALDI-TOF mass spectrometry. From the 126 studied animals, 112 were positive for bacterial isolation. Among the positive animals, 32.1% presented infection caused by a single bacterial species, while in the remaining 67.9%, two to six different bacterial species were identified. A total of 259 bacterial strains were obtained and classified among 46 bacterial species. The species of higher frequency were Aeromonas veronii (26.3%), Aeromonas hydrophilla (16.2%), Shewanella putrefaciens (7.3%), Citrobacter freundii (8.1%), Vibrio albensis (5.8%), and Klebsiella pneumoniae (4.2%). MALDI-TOF MS showed to be a rapid method for diagnosis of bacterial disease outbreaks in ornamental fish establishments.

Scuticociliatosis caused by Uronema sp. in ten different ornamental aquarium reef fish in Brazil

Scuticociliatosis, caused by an opportunistic ciliate protozoan, is responsible for significant economic losses in marine ornamental fish. This study reports the occurrence of Uronema spp., parasitizing ten species of marine reef fish at an ornamental fish wholesaler: Blue green damselfish (Chromis viridis), Vanderbilt's Chromis (Chromis vanderbilti), Pennant coralfish (Heniochus acuminatus), Threespot angelfish (Apolemichthys trimaculatus), Goldspotted angelfish (Apolemichthys xanthopunctatus), Sea goldie (Pseudanthias squamipinnis), Orchid dottyback (Pseudochromis fridmani), Threadfin butterflyfish (Chaetodon auriga), Vagabond butterflyfish (Chaetodon vagabundus), and Bluecheek butterflyfish (Chaetodon semilarvatus). Diseased fish showed disorders such as hemorrhages and ulcerative lesions on the body surface. Histopathological analysis of the muscle, liver, gut, kidney, spleen, gills, and stomach revealed hemorrhages and degeneration of muscle fiber, vacuolar degeneration of hepatocyte, inflammatory process and granuloma in the liver, atrophy of intestinal villi, inflammatory process and granuloma in the kidney, melanomacrophage centers, as well as inflammatory process in the spleen, epithelial cells hyperplasia and granuloma formation in the gills, and vacuolar degeneration and eosinophils in the stomach. Due to the severity of the disease, it is necessary to implement biosecurity measures with rapid and accurate diagnosis to minimize the risk of economic losses caused by Uronema spp.

Epidemiological analysis of Trueperella abortisuis isolated from cases of pig abortion of a single farm

The present study was designed to characterize six Trueperella (T.) abortisuis strains, cultured over a period of 5 months from fetus and abortion material of six pigs of a single farm in Mecklenburg-West Pomerania federal state, Germany. It was of interest to investigate the epidemiological relationships of the six strains among each other and whether a single bacterial clone was responsible for the abortion situation of the single farm. All six strains were identified phenotypically, by MALDI-TOF MS analysis and by phylogenetic analysis based on 16S rRNA gene and gap (encoding the glyceraldehyde 3-phosphate dehydrogenase) and tuf (encoding elongation factor tu) gene sequencing. Further genotypic comparison was performed using different genomic DNA fingerprint methods including BOX-PCR, (GTG)₅-PCR, and three RAPD-PCRs. The sequence analysis of the genes gap and tuf and the genomic DNA fingerprinting results revealed, as noval findings, that the six T. abortisuis strains cultured from a single farm represent six different bacterial clones showing a genetic variability of this bacterial species in the pig population. All six T. abortisuis strains were isolated in mixed culture with several other bacterial species. However, the T. abortisuis strain, generally found in high numbers, seemed to be responsible for the abortion situation in the farm.

Identification through MALDI-TOF mass spectrometry and antimicrobial susceptibility profiling of bacterial pathogens isolated from sow urinary tract infection

BACKGROUND

Urinary tract infection (UTI) is a common disease in sows due to intensification of pig production. Despite direct economic losses, UTI prevalence and respective microbial identification are still poorly studied.

OBJECTIVE

The aims of this study were to identify the causative agents of UTI in sows through MALDI-TOF MS and to characterize their antimicrobial resistance profiles.

MATERIALS AND METHODS

Urine samples from 300 sows of three herds from São Paulo State (Brazil) were screened for UTI; suggestive samples were submitted to bacterial isolation. Species identification was performed by MALDI-TOF MS and susceptibility profiles were determined using disc diffusion method.

RESULTS

128 samples suggestive of UTI were analyzed; 48% of the animals presented UTI caused by a single pathogen, while the remaining 52% presented mixed infection. Escherichia coli stood out with the highest frequency among both single and mixed infections. The Gram-positive were exclusively associated with 27% of single infections. The mixed infections were further classified into 49 profiles. The high frequency of multiresistant profiles stood out for most of the studied isolates.

CONCLUSIONS

MALDI-TOF MS enabled the identification of rare pathogens related to UTI which may represent higher risk for porcine health, especially considering high frequency of multiresistant profiles.

Successful Treatment of Olecranon Bursitis Caused by Trueperella bernardiae: Importance of Environmental Exposure and Pathogen Identification

A livestock farmer with a history of arthropathy presented with unilateral olecranon bursal swelling and tenderness. Multiple wound and intraoperative cultures revealed growth of Trueperella bernardiae, a Gram-positive coccobacillus, with symptom resolution following appropriate antimicrobial therapy. To our knowledge, this is the first case report of olecranon bursitis caused by this organism. Coryneform bacteria are often regarded as contaminants in clinical cultures, but advanced techniques for species identification may reveal expanded pathogenic potential of individual species like T. bernardiae and elucidate epidemiologic clues for osteoarticular infections in these cases.

Further characteristics of Arcanobacterium pinnipediorum DSM 28752T and Arcanobacterium wilhelmae DSM 102162T, two novel species of genus Arcanobacterium

The newly described type strains Arcanobacterium pinnipediorum DSM 28752^T and Arcanobacterium wilhelmae DSM 102162^T, initially isolated from an anal swab of a harbor seal (Sammra et al. Int J Syst Evol Microbiol 65:4539-4543, 2015) and the genital tract of a rhinoceros (Sammra et al. Int J Syst Evol Microbiol 67:2093-2097, 2017), could be further characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared (FT-IR) spectroscopy and by sequencing the genomic targets 16S-23S rDNA intergenic spacer region (ISR) and the genes rpoB, gap, and tuf. The two strains investigated in the present study were isolated together with several other bacterial species indicating that the pathogenic importance of both species remained unclear. However, the detection of specific spectra by MALDI-TOF MS and by FT-IR spectroscopy and the presented genotypic approaches might help to identify A. pinnipediorum and A. wilhelmae in the future and might elucidate the role these two species play in infections of animals.

Identification of Arcanobacterium phocae isolated from fur animals by phenotypic properties, by MALDI-TOF MS analysis and by detection of phocaelysin encoding gene phl as probable novel target

In the present study 12 Arcanobacterium phocae strains isolated from fur animals in Finland, including foxes, minks and Finnraccoons, could successfully be identified phenotypically, by matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) and genotypically by sequencing 16S rDNA and phocaelysin (PHL) encoding gene phl. The PHL of all 12 A. phocae strains in the present study and reference strains A. phocae DSM 10002^T and A. phocae DSM 10003 displayed, as typical members of the cholesterol dependent cytolysin-group of toxins, the variant undecapeptide sequence EATGLAWDPWW which appeared to be most closely related to arcanolysin of Arcanobacterium haemolyticum and pyolysin of Trueperella pyogenes. In addition, gene phl could be determined with a newly designed loop-mediated isothermal amplification (LAMP) assay. The detection of mass spectra by MALDI-TOF MS and the LAMP assay based on gene phl might help to reliably identify A. phocae in future and also elucidate the role this species plays in infections of fur animals.

Two Rare Cases of Wound Infections Caused by Trueperella bernardiae

Trueperella bernardiae (T.bernardiae) is a gram-positive curved rod that is considered an uncommon pathogen involved in few infections. The true incidence of infections with this bacterium, and the clinical implications, remain unknown. We report 2 cases of wound infections in 2 patients who underwent different surgical procedures, although in the second case the microorganism was isolated in mixed culture. Culture of wound secretions resulted in isolation of T. bernardiae. Treatment was performed and resolution of the infections was documented.

Evaluation of MALDI-TOF mass spectrometry and MALDI BioTyper in comparison to 16S rDNA sequencing for the identification of bacteria isolated from Arctic sea water

MALDI-TOF Mass Spectrometry in association with the MALDI BioTyper 3.1 software has been evaluated for the identification and classification of 45 Arctic bacteria isolated from Kandalaksha Bay (White Sea, Russia). The high reliability of this method has been already demonstrated, in clinical microbiology, by a number of studies showing high attribution concordance with other credited analyses. Recently, it has been employed also in other branches of microbiology with controversial performance. The phyloproteomic results reported in this study were validated with those obtained by the "gold standard" 16S rDNA analysis. Concordance between the two methods was 100% at the genus level, while at the species level it was 48%. These percentages appeared to be quite high compared with other studies regarding environmental bacteria. However, the performance of MALDI BioTyper changed in relation to the taxonomical group analyzed, reflecting known identification problems related to certain genera. In our case, attribution concordance for Pseudomonas species was rather low (29%), confirming the problematic taxonomy of this genus, whereas that of strains from other genera was quite high (> 60%). Among the isolates tested in this study, two strains (Exiguobacterium oxidotolerans and Pseudomonas costantinii) were misidentified by MALDI BioTyper due to absence of reference spectra in the database. Accordingly, missing spectra were acquired for the database implementation.

Characterization of porcine Trueperella pyogenes by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), molecular typing and antimicrobial susceptibility profiling in Sao Paulo State

Trueperella pyogenes can be found as a commensal or pathogenic bacterium among animals causing a variety of pyogenic infections in several species. The agent appears to act primarily as an opportunistic pathogen but may disseminate and produce metastatic abscesses accompanied or not by mastitis, metritis or pneumonia. In this study, 30 porcine T. pyogenes strains were identified by MALDI-TOF MS and 16S rRNA sequencing and further evaluated in relation to their resistance and genetic profiles through broth microdilution and single enzyme AFLP. All strains were susceptible to β-lactams, florfenicol, gentamicin, spectinomycin and tiamulin. The highest resistance rates were observed for sulfonamides, tetracyclines and clindamycin. All isolates could be characterized by SE-AFLP presenting more than 80% of similarity, despite their distinct origins. Four genotypes were detected with the segregation of T. pyogenes ATCC 19411 from Brazilian T. pyogenes strains. No correlation between genotypes and isolates origins and susceptibility profile was observed.

Trueperella bernardiae: first report of wound infection post laparoscopic surgery

We report the first case of wound infection caused by Trueperella bernardiae after laparoscopic surgery. The patient was treated with oral amoxicillin/clavulanate which was continued for 1 week after discharge with a successful clinical response. There are few cases described but none related to wound infection after laparoscopic surgery.

Prosthetic joint infection caused by Trueperella bernardiae

Trueperella bernardiae is a Gram-positive coryneform bacilli which role as human pathogen is unknown because it has been usually considered a contaminant. Furthermore its identification by biochemical test was difficult. We describe a prosthetic joint infection in a women who years ago underwent a total knee replacement with superinfection and necrosis of the patellar tendon as major complications. In the sample of synovial fluid collected grew a gram-positive bacilli which was identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) as T. bernardiae. The patient was treated with ciprofloxacin and currently preserves the prosthesis without signs of infection.

Molecular and antibiotic susceptibility characterization of Aerococcus viridans isolated from porcine urinary infection

Aerococcus viridans has been reported as a human and animal pathogen causing urinary tract infection, arthritis, pneumonia, meningitis and endocarditis. Routinely, A. viridans is not surveyed in clinical diagnosis laboratories and commonly is misidentified as other bacteria. There is no concrete data on the prevalence and impact of the pathogen to both human and animal health. In the present study, we report the isolation and molecular and antibiotic susceptibility characterization of A. viridans strains from porcine urinary infections. A total of 22 isolates were identified as A. viridans by MALDI-TOF MS and confirmed by 16S rRNA gene sequencing. Isolates were genotyped by single enzyme amplified fragments length polymorphism (SE-AFLP) that resulted in 19 clusters of which 81.2% were composed by single isolates. The high genetic heterogeneity corroborates previous studies and appears to be a particularity of A. viridans. The minimal inhibitory concentration (MIC) values also presented variability especially for ceftiofur, fluoroquinolones and aminoglycosides. The high MICs of aminoglycosides, tetracyclines and macrolides seen among the A. viridans corroborate previous reports and the widespread veterinary usage of these antibiotics demand attention for the implication of A. viridans infection to both human and animal health.

MALDI-TOF mass spectrometry: an emerging technology for microbial identification and diagnosis

Currently microorganisms are best identified using 16S rRNA and 18S rRNA gene sequencing. However, in recent years matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potential tool for microbial identification and diagnosis. During the MALDI-TOF MS process, microbes are identified using either intact cells or cell extracts. The process is rapid, sensitive, and economical in terms of both labor and costs involved. The technology has been readily imbibed by microbiologists who have reported usage of MALDI-TOF MS for a number of purposes like, microbial identification and strain typing, epidemiological studies, detection of biological warfare agents, detection of water- and food-borne pathogens, detection of antibiotic resistance and detection of blood and urinary tract pathogens etc. The limitation of the technology is that identification of new isolates is possible only if the spectral database contains peptide mass fingerprints of the type strains of specific genera/species/subspecies/strains. This review provides an overview of the status and recent applications of mass spectrometry for microbial identification. It also explores the usefulness of this exciting new technology for diagnosis of diseases caused by bacteria, viruses, and fungi.

Brain abscess due to Trueperella bernardiae

We present the case of a brain abscess caused by a combination of rare organisms (Trueperella bernardiae and Peptoniphilus harei) in a patient with chronic suppurative otitis media that had been complicated by the presence of a cholesteatoma. The authors believe this is the first report published in the literature.