Browsing by Person "Hoelzle, Ludwig E."

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An evaluation of the lineage of Brucella isolates in turkey by a whole-genome single-nucleotide polymorphism analysis
(2024) Akar, Kadir; Holzer, Katharina; Hoelzle, Ludwig E.; Yıldız Öz, Gülseren; Abdelmegid, Shaimaa; Baklan, Emin Ayhan; Eroğlu, Buket; Atıl, Eray; Moustafa, Shawky A.; Wareth, Gamal; Elkhayat, Manar; Pedersen, Karl
Brucellosis is a disease caused by the Brucella ( B. ) species. It is a zoonotic disease that affects farm animals and causes economic losses in many countries worldwide. Brucella has the ability to persist in the environment and infect the host at low doses. Thus, it is more important to trace brucellosis outbreaks, identify their sources of infection, and interrupt their transmission. Some countries already have initial data, but most of these data are based on a Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA), which is completely unsuitable for studying the Brucella genome. Since brucellosis is an endemic disease in Turkey, this study aimed to examine the genome of Turkish Brucella isolates collected between 2018 and 2020, except for one isolate, which was from 2012. A total of 28 strains of B. melitensis ( n = 15) and B. abortus ( n = 13) were analyzed using a core-genome single-nucleotide polymorphism (cgSNP) analysis. A potential connection between the Turkish isolates and entries from Sweden, Israel, Syria, Austria, and India for B. melitensis was detected. For B. abortus , there may be potential associations with entries from China. This explains the tight ties found between Brucella strains from neighboring countries and isolates from Turkey. Therefore, it is recommended that strict measures be taken and the possible effects of uncontrolled animal introduction are emphasized.
Clinical, haematological and pathomorphological findings in Mycoplasma suis infected pigs
(2021) Stadler, Julia; Ade, Julia; Hermanns, Walter; Ritzmann, Mathias; Wentzel, Sarah; Hoelzle, Katharina; Hoelzle, Ludwig E.
Background: Mycoplasma suis (M. suis) belongs to the group of haemotrophic mycoplasmas and is known as the causative agent of infectious anaemia in pigs. In the last few years valuable insights into the mechanism of adhesion and invasion, shedding patterns and cell tropism of M. suis were gained by the use of new molecular techniques. However, details on M. suis induced lesions as well as the distribution of M. suis in different organs are still lacking. Therefore, seven splenectomised pigs were experimentally infected and clinical and laboratory investigations as well as a detailed histopathological examination were performed. Detection and quantification of M. suis DNA in blood and various tissue samples was done using a quantitative real-time PCR. Results: During the course of experimental infection, periodically occurring signs of infectious anaemia of pigs including severe icteroanaemia, fever, apathy and anorexia were observed. In addition, dermatological manifestations such as haemorrhagic diathesis presenting as petechiae occurred. The most important haematological alterations were normochromic, normocytic anaemia, hypoglycaemia as well as increased bilirubin and urea concentrations. Necropsy revealed predominant evidence of haemolysis with consecutive anaemia, as well as disseminated intravascular coagulation. M. suis was found in all investigated tissues with the highest copy numbers found in the kidneys. In Giemsa stained sections M. suis was only detected red blood cell (RBC)-associated. Conclusion: In the present study, no RBC independent sequestration of M. suis was detected in organs of experimentally infected pigs. Pathological findings are most likely resulting from haemolysis, consecutive anaemia as well as from disseminated intravascular coagulation and subsequent organ impairments.
Determination of optimal phage load and administration time for antibacterial treatment
(2024) Plunder, Steffen; Burkard, Markus; Helling, Thomas; Lauer, Ulrich M.; Hoelzle, Ludwig E.; Marongiu, Luigi
Using phages as antibacterials is becoming a customary practice in Western countries. Nonetheless, successful treatments must consider the growth rate of the bacterial host and the degradation of the virions. Therefore, successful treatments require administering the right amount of phage (viral load, Vφ) at the right moment (administration time, Tφ). The present protocols implement a machine learning approach to determine the best combination of Vφ and Tφ to obtain the elimination of the target bacterium from a system. Basic Protocol 1: One bacterium, one phage. Alternate Protocol 1: One bacterium, one phage (wrapping function). Alternate Protocol 2: One bacterium, one phage (wrapping function, alternative growing model). Basic Protocol 2: Two bacteria, one phage. Alternate Protocol 3: Two bacteria, one phage (launch from terminal).
Haemotrophic mycoplasmas infecting pigs: a review of the current knowledge
(2024) Ade, Julia; Eddicks, Matthias; Ritzmann, Mathias; Hoelzle, Katharina; Hoelzle, Ludwig E.; Stadler, Julia; Highland, Margaret A.
Haemotrophic mycoplasmas (haemoplasmas) are a group of highly specific and adapted bacteria. Three different haemoplasma species in pigs are known to date: Mycoplasma ( M .) suis , M. parvum and ‘ Candidatus ( Ca .) M. haemosuis’. Even though these bacteria have been known in pig farming for a long time, it is difficult to draw general conclusions about the relevance of their infections in pigs. This review summarizes the current knowledge on the three porcine haemoplasma species with regards to clinical and pathological descriptions, pathobiology, epidemiology and diagnostics as well as prevention and therapy. Overall, it is clear that considerably more data are available for M. suis than for the other two species, but generally, porcine haemoplasmas were found to be highly prevalent all over the world. Mycoplasma suis is the most virulent species, causing acute infectious anaemia in pigs (IAP), whereas M. parvum usually results in chronic and subclinical infections associated with performance losses. Little is known about the clinical significance of the recently discovered third porcine species ‘ Ca . M. haemosuis’. So far, the described pathogenic mechanisms mainly include direct destruction of erythrocytes via adhesion, invasion, eryptosis and nutrient scavenging, indirect erythrocyte lysis due to immune-mediated events and immune dysregulation processes. A review of published diagnostic data confirms PCR assays as the current standard method, with various cross-species and species-specific protocols. Overall, there is a need for further examination to obtain valuable insights for practical application, specifically regarding the importance of subclinical infections in naturally infected animals. An essential requirement for this will be to gain a more comprehensive understanding of the mechanisms operating between the host and the pathogen.
Hemotrophic mycoplasmas - vector transmission in livestock
(2024) Arendt, Mareike; Stadler, Julia; Ritzmann, Mathias; Ade, Julia; Hoelzle, Katharina; Hoelzle, Ludwig E.; Dozois, Charles M.
Hemotrophic mycoplasmas (HMs) are highly host-adapted and specialized pathogens infecting a wide range of mammals including farm animals, i.e., pigs, cattle, sheep, and goats. Although HMs have been known for over 90 years, we still do not know much about the natural transmission routes within herds. Recently, it has been repeatedly discussed in publications that arthropod vectors may play a role in the transmission of HMs from animal to animal. This is mainly since several HM species could be detected in different potential arthropod vectors by PCR. This review summarizes the available literature about the transmission of bovine, porcine, ovine, and caprine HM species by different hematophagous arthropod vectors. Since most studies are only based on the detection of HMs in potential vectors, there are rare data about the actual vector competence of arthropods. Furthermore, there is a need for additional studies to investigate, whether there are biological vectors in which HMs can multiply and be delivered to new hosts.
Lactic acid fermentation inactivates Salmonella Typhimurium in contaminated cattle manure at moderate and low temperatures
(2025) Halm, Hannah; Woelke, Sören; Lehnert, Ines; Schilling, Thorben; Meissner, Thorsten; Schröder, Charlotte; Hoelzle, Ludwig E.; Scheinemann, Hendrik A.; Britz, Margaret L.
In the case of a notifiable animal disease like salmonellosis, manure is contaminated and must be disinfected. This can be performed using heat measures, chemical disinfectants, or long-term storage. All these measures bring along severe economic, ecological, and logistical problems. The aim of this study was to evaluate lactic acid fermentation (LAF) as an alternative disinfection method. Fermentation was started by adding a carbohydrate source to the manure and creating anaerobic conditions. For testing, cattle manure was enriched with different carbohydrate (CHO) sources and spiked with Salmonella Typhimurium ( S. Ty.). The samples were incubated at 10 °C and 21 °C for 111 days (Exp1) and at 21 °C for 50 days (Exp2). The microbial shift was determined using cultural methods and MALDI-TOF. Both the change in pH and Enterococcus spp. were tested as suitable indicators. The results showed the different suitability of the selected CHO for hygienization by LAF. Using squeezed oat as an additive, S. Ty was reduced to below the detection limit under both temperature conditions within 21 days and 14 days. Additional saccharose decreased the reduction time. This study showed that LAF is a valuable alternative for disinfecting cattle manure in the case of bovine salmonellosis. Using this method, both manure and feed residues can be treated in one approach and afterwards be used as fertilizer.
Occurrence and quantification of porcine hemotrophic mycoplasmas in blood-sucking Stomoxys calcitrans
(2025) Arendt, Mareike; Hoelzle, Katharina; Stadler, Julia; Ritzmann, Mathias; Ade, Julia; Hoelzle, Ludwig E.; Schwarz, Lukas; Rossi, Franca
Hemotrophic mycoplasmas (HMs) are cell wall-less, small and uncultivable pathogens, which can cause infections in pigs with no to severe clinical signs and can contribute to significant economic losses in the pig industry. In addition to the known mechanical transmission routes of HMs (e.g., via blood-contaminated instruments or lesions from ranking fights), transmission to pigs by arthropod vectors such as Stomoxys calcitrans is being discussed. To date, there is scant available data concerning the transmission of HMs by stable flies. The objective of this study is to gain more data concerning the occurrence of HMs in Stomoxys calcitrans . Therefore, quantitative real-time PCR was conducted on different stable fly samples (surface washings and whole flies). We found Mycoplasma ( M. ) suis in 5.2% of crushed flies and 4.2% of fly wash solutions, and M. parvum was detected in 5.2% of flies and 9.4% of fly wash solutions. ‘ Candidatus ( Ca .) M. haemosuis’ was not detected in any sample. The mean bacterial loads were 2.0 × 10 2 M. suis /fly, 9.3 × 10 2 M. suis /fly wash solution and, for M. parvum , 2.4 × 10 3 M. parvum /fly and 2.1 × 10 3 M. parvum /fly wash solution. This molecular occurrence of porcine HMs in blood-sucking flies and reasonable bacterial loads in the two- to three-digit range demonstrate that these flies serve as mechanical vectors in stables and are, therefore, of epidemiological importance.
Occurrence of ‘Candidatus Mycoplasma haemosuis’ in fattening pigs, sows and piglets in Germany using a novel gap-based quantitative real-time PCR assay
(2022) Ade, Julia; Stadler, Julia; Ritzmann, Mathias; Zübert, Christina; Hoelzle, Katharina; Hoelzle, Ludwig E.
Background: The appearance of the novel porcine haemotrophic mycoplasma (HM) species ‘Candidatus Mycoplasma haemosuis’ was reported in apparently healthy but also in clinically sick animals in China, Korea and in a case report from Germany. Outside of Asia, however, nothing further is known about the frequency of ‘Ca. M. haemosuis’ in pigs to date. To investigate the distribution of this novel HM species in Germany, fattening pigs, sows and pre-suckling piglets were examined using a herein developed quantitative real-time PCR assay (qPCR). Because the piglets were sampled before the first colostrum uptake, additional information on a possible vertical transmission from dams to their offspring was obtained. Results: Our novel qPCR assay successfully detected ‘Ca. M. haemosuis’ in all blood samples from the ‘Ca. M. haemosuis’-infected pigs. No cross-reactivity was detected when DNA from non-target Mycoplasma spp. and other bacterial species representing 105 bacteria/reaction were used as a template. The lower limit of detection of the qPCR was thus 10 gap gene copies per reaction and 2.5 x 103 genome equivalents (GE) per mL blood. ‘Candidatus M. haemosuis’ was detected by this qPCR in blood samples from a total out of 6.25% sows (13/208), 4.50% pre-suckling piglets (28/622) and 17.50% fattening pigs (35/200). On farm level, 3 out of 21 piglet producing farms (14.28%) and 9 out of 20 fattening farms (45.00%) were positive for ‘Ca. M. haemosuis’. Co-infections with M. suis were evident in all age groups. Conclusion: ‘Candidatus M. haemosuis’ infection is present in German pig farms and the detection of the novel porcine HM species in piglets immediately after birth before colostrum intake indicates vertical transmission. The novel qPCR assay specific for ‘Ca. M. haemosuis’ described herein will be a prerequisite for future studies on the prevalence, epidemiology as well as the clinical and economic impact of ‘Ca. M. haemosuis’ infections.
Update on shedding and transmission routes of porcine haemotrophic mycoplasmas in naturally and experimentally infected pigs
(2021) Ade, Julia; Ritzmann, Mathias; Wöstmann, Christopher; Eddicks, Matthias; Reese, Sven; Hoelzle, Katharina; Hoelzle, Ludwig E.; Stadler, Julia
Horizontal transmission of Mycoplasma suis via parenteral exposure during standard practices or through bites during fightings have been identified as key epidemiological routes. However, as knowledge gaps on other potential shedding and transmission routes exist, the present study combines both laboratory experiments and field surveys to gain new insights into the epidemiology of porcine haemotrophic mycoplasmas. Splenectomised pigs were orally inoculated with a M. suis field strain and investigated for clinical signs related to infectious anaemia of pigs (IAP) and the presence of M. suis in blood, urine and saliva samples by qPCR. All blood samples were negative for M. suis and animals did not show obvious clinical signs of IAP throughout the entire study period. Additionally, urine, nasal and saliva samples from sows of conventional piglet producing farms and semen samples from a boar stud revealed no detection of M. suis and ‘Candidatus Mycoplasma haemosuis’ by qPCR. Thus, the results indicate that blood-independent transmission routes might be of minor relevance under field conditions.