Acute severe spinal cord dysfunction in a child with meningitis: Streptococcus pneumoniae and Mycoplasma pneumoniae co-infection

Simulated acute central Mycoplasma infections in rats induce fever, anorexia, body mass stunting and lethargy but spare memory

Despite the documented post-infectious neurological complications of a central nervous system (CNS) Mycoplasma infection in humans, very few studies have investigated the acute inflammatory responses and sickness behaviours induced by CNS Mycoplasma infections. We therefore determined the effect of acute central administration of fibroblast-stimulating lipopeptide-1 (FSL-1), derived from Mycoplasma salivarium, and FAM-20 from a more pathogenic species, namely Mycoplasma pneumoniae, on behavioural and inflammatory responses in rats. Male Sprague-Dawley rats had radiotransmitters implanted, intra-abdominally, to measure body temperature and cage activity continuously. After recovery from surgery, rats were conditioned in a fear conditioning task and then immediately received an intra-cisterna magna (i.c.m.) injection of either: (1) FSL-1 (10 or 100μg/5μl) or its vehicle (phosphate-buffered saline, 5μl), or (2) FAM-20 (10 or 100μg/5μl) or its vehicle (dimethyl sulfoxide, 5μl). Body mass and food intake were measured daily. Memory was assessed seven days after injection using fear conditioning tests. A single, i.c.m. injection of either FSL-1 or FAM-20 induced profound, dose-dependent fever, anorexia, lethargy and body mass stunting in rats. Moreover, rats that received an i.c.m. injection of 100μg/5μl FAM-20 had a significant increase in the concentration of IL-1β in both the hypothalamus and the hippocampus for ~27h after injection. Seven days after FSL-1 or FAM-20 injection, when body mass of rats still was stunted, they maintained their memory for fear of the context and for fear of the tone, despite the increase in hippocampal IL-1β concentration after FAM-20 administration. Thus, acute simulated CNS Mycoplasma infections caused pronounced sickness responses and brain inflammation in rats, but spared fear memory.

Chronic Lyme Disease and Co-infections: Differential Diagnosis

In Lyme disease concurrent infections frequently occur. The clinical and pathological impact of co-infections was first recognized in the 1990th, i.e. approximately ten years after the discovery of Lyme disease. Their pathological synergism can exacerbate Lyme disease or induce similar disease manifestations. Co-infecting agents can be transmitted together with Borrelia burgdorferi by tick bite resulting in multiple infections but a fraction of co-infections occur independently of tick bite. Clinically relevant co-infections are caused by Bartonella species, Yersinia enterocolitica, Chlamydophila pneumoniae, Chlamydia trachomatis, and Mycoplasma pneumoniae. In contrast to the USA, human granulocytic anaplasmosis (HGA) and babesiosis are not of major importance in Europe. Infections caused by these pathogens in patients not infected by Borrelia burgdorferi can result in clinical symptoms similar to those occurring in Lyme disease. This applies particularly to infections caused by Bartonella henselae, Yersinia enterocolitica, and Mycoplasma pneumoniae. Chlamydia trachomatis primarily causes polyarthritis. Chlamydophila pneumoniae not only causes arthritis but also affects the nervous system and the heart, which renders the differential diagnosis difficult. The diagnosis is even more complex when co-infections occur in association with Lyme disease. Treatment recommendations are based on individual expert opinions. In antibiotic therapy, the use of third generation cephalosporins should only be considered in cases of Lyme disease. The same applies to carbapenems, which however are used occasionally in infections caused by Yersinia enterocolitica. For the remaining infections predominantly tetracyclines and macrolides are used. Quinolones are for alternative treatment, particularly gemifloxacin. For Bartonella henselae, Chlamydia trachomatis, and Chlamydophila pneumoniae the combination with rifampicin is recommended. Erythromycin is the drug of choice for Campylobacter jejuni.

Mycoplasma pneumoniae central nervous system infections

PURPOSE OF REVIEW

Mycoplasma pneumoniae is associated with a wide range of central nervous system diseases, most importantly with childhood encephalitis. This review summarizes and discusses recent findings in the field of M. pneumoniae central nervous system infections in context with previously published findings, with reference to clinical spectrum, pathogenesis, diagnosis, and treatment.

RECENT FINDINGS

Further insight into the pathogenesis has been provided by studies on cytokine production and autoantibody formation. Some new manifestations have been described (e.g. Kluver-Bucy syndrome, intracranial hypertension). Anecdotal descriptions on the association of M. pneumoniae with uncommon neurologic diseases remain to be confirmed by additional reports, however, especially when aetiologic diagnosis relied exclusively on serology. New knowledge on treatment options targeting the immune system has been provided by isolated reports. Recent diagnostic advances refer to general methods (polymerase chain reaction, serology), without specific reference to neurologic disease.

SUMMARY

M. pneumoniae must be considered as causative agent of various neurologic diseases. The recent literature shows, however, that the clinical spectrum of M. pneumoniae central nervous system disease is still not well defined. In addition, the main future challenges are the investigation of the pathogenesis of M. pneumoniae central nervous system disease and the establishment of therapeutic approaches.