Canaliculitis caused byCitrobacter freundii

Lacrimal Canaliculitis: A Major Review

Lacrimal canaliculitis is an inflammation of the proximal lacrimal drainage system. It classically presents with symptoms of redness, mucopurulent discharge, medial canthal swelling, epiphora, and pouting punctum. Despite having classical clinical characteristics it is frequently misdiagnosed. The cause can be primarily due to various infectious agents or secondary mostly due to the use of punctal plugs. There are no universally accepted guidelines for the management of canaliculitis but different medical and surgical options have been employed with varying success rates and it is notorious for recurrences and failure to therapy. The present review summarizes the existing literature on lacrimal canaliculitis published over the past 15 years to provide an overview of this uncommon condition. A total of 100 articles published in the literature were anlaysed during this period. The mean age at diagnosis was 57.09 ± 16.91 years with a female preponderance. Misdiagnosis was common with many patients misdiagnosed as conjunctivitis and dacryocystitis. Primary canaliculitis was found to be more frequent than secondary with inferior canaliculus involved more commonly than the superior. Staphylococcus, Streptococcus, and Actinomyces were the most common microbes isolated. Surgical management was employed in 74.25% of cases while medical management was done in 20.82% of cases. The review presents an insight into the complexities of canaliculitis, its diagnosis, and management which will further help to improve the understanding of this uncommon infection of the lacrimal system.

Isolation and identification of Chryseobacterium indologenes and its pathological changes in Pelodiscus sinensis

The Chinese revered a species of aquatic reptile known as Pelodiscus sinensis as both an edible and medicinal species. When artificially breeding, many deaths occurred at the farmed P. sinensis, mainly due to excessive breeding density, water contamination, and turtles biting each other secondary to bacterial infections. In this study, an isolate of gram-negative bacteria WH0623 was isolated from the liver and kidney of diseased P. sinensis to trace the potential pathogen of this disease. Based on biochemical characteristics and 16S rRNA gene sequencing analyses, this isolated strain of WH0623 was identified as Chryseobacterium indologenes. The strain's median lethal dose (LD50 ) was 3.3 × 105 colony-forming units (CFU)/g per fish weight tested using artificial infection. Histopathological analysis revealed pathological changes, including cell swelling, hyperaemia, and necrosis in many tissues. Antibiotic susceptibility tests revealed that the bacteria WH0623 was susceptible to doxycycline, sulphonamides, ceftazidime, norfloxacin, and ciprofloxacin. These antibiotics could treat the disease. In conclusion, the pathogen causing the death of farmed P. sinensis was isolated and identified, and a drug-sensitive test was conducted. Our findings contribute to the future diagnosis and treatment of the disease.

[Formation of concrements in the lacrimal excretory system]

Studying the pathogenesis of concrements formation in lacrimal ducts is of fundamental and practical importance. This article attempts to analyze available information related to the pathogenesis of this phenomenon, provides information on the etiopathogenesis, physical and chemical properties of concrements obtained from horizontal and vertical parts of the lacrimal duct, and considers in detail bacteriological and mycotic composition of concrements, as well as various theories of their formation. The analysis helped justify the need to separate the concrements formed in the horizontal and vertical parts of the lacrimal ducts on the basis of differences in their pathogenesis. Actinomycotic infection is the cause of concrements formation in the horizontal part of the lacrimal duct in the overwhelming majority of cases. The process of concrements formation in the vertical part of the lacrimal duct in some cases occurs as a result of previous clinical events, but in many other cases the trigger mechanisms remain unknown. To date, the role of the initial narrowing of the lacrimal ducts in the pathogenesis of concrements is not clearly defined. The accumulated knowledge regarding the pathogenesis of concrements is currently not enough to formulate a complete theory of the development of this phenomenon. Further studies of the pathogenesis of concrements will help develop new diagnostic and therapeutic measures aimed at restoring the patency of the lacrimal ducts.

Raman-Deuterium Isotope Probing for in-situ identification of antimicrobial resistant bacteria in Thames River

The emergence and widespread distribution of antimicrobial resistant (AMR) bacteria has led to an increasing concern with respect to potential environmental and public health risks. Culture-independent and rapid identification of AMR bacteria in-situ in complex environments is important in understanding the role of viable but non-culturable and antibiotic persistent bacteria and in revealing potential pathogens without waiting for colony formation. In this study, a culture-independent and non-destructive phenotyping approach, so called Raman Deuterium Stable Isotope Probing (Raman-DIP), was developed to identify AMR bacteria in the River Thames. It is demonstrated that Raman-DIP was able to accurately identify resistant and susceptible bacteria within 24 hours. The work shows that, in the River Thames, the majority of the bacteria (76 ± 2%) were metabolically active, whilst AMR bacteria to carbenicillin, kanamycin and both two antibiotics were 35 ± 5%, 28 ± 3%, 25 ± 1% of the total bacterial population respectively. Raman activated cell ejection (RACE) was applied to isolate single AMR bacteria for the first time, linking AMR phenotype (reistance to antibiotics) and genotype (DNA sequence). The sequences of the RACE sorted cells indicate that they were potential human pathogens Aeromonas sp., Stenotrophomonas sp. and an unculturable bacterium. This work demonstrates Raman-DIP and RACE are effective culture-independent approach for rapid identification of AMR bacteria at the single cell level in their natural conditions.