Enterobacter Meningitis and Challenges in Treatment

Apirhabdus apintestini gen. nov., sp. nov., a member of a novel genus of the family Enterobacteriaceae, isolated from the gut of the western honey bee Apis mellifera

A Gram-negative, motile, rod-shaped bacterial strain, CA-0114T, was isolated from the midgut of a western honey bee, Apis mellifera. The isolate exhibited ≤96.43 % 16S rRNA gene sequence identity (1540 bp) to members of the families Enterobacteriaceae and Erwiniaceae. Phylogenetic trees based on genome blast distance phylogeny and concatenated protein sequences encoded by conserved genes atpD, fusA, gyrB, infB, leuS, pyrG and rpoB separated the isolate from other genera forming a distinct lineage in the Enterobacteriaceae. In both trees, the closest relatives were Tenebrionicola larvae YMB-R21T and Tenebrionibacter intestinalis BIT-L3T, which were isolated previously from Tenebrio molitor L., a plastic-eating mealworm. Digital DNA-DNA hybridization, orthologous average nucleotide identity and average amino acid identity values between strain CA-0114T and the closest related members within the Enterobacteriaceae were ≤23.1, 75.45 and 76.04 %, respectively. The complete genome of strain CA-0114T was 4 451669 bp with a G+C content of 52.12 mol%. Notably, the apparent inability of strain CA-0114T to ferment d-glucose, inositol and l-rhamnose in the API 20E system is unique among closely related members of the Enterobacteriaceae. Based on the results obtained through genotypic and phenotypic analysis, we propose that strain CA-0114T represents a novel species and genus within the family Enterobacteriaceae, for which we propose the name Apirhabdus apintestini gen. nov., sp. nov. (type strain CA-0114T=ATCC TSD-396T=DSM 116385T).

Phenotypic and genomic insights into the pathogenicity and antimicrobial resistance of an Enterobacter roggenkampii strain isolated from diseased silver arowana (Osteoglossum bicirrhosum)

Enterobacter roggenkampii is an opportunistic pathogen that causes infections in a wide range of hosts. A bacterial strain named EOBSR_19 was isolated from diseased silver arowana, Osteoglossum bicirrhosum. This bacterium was identified as E. roggenkampii based on the phenotypic characteristics and sequence analysis of the16S rDNA and gyrB genes. Average nucleotide identity and phylogenetic analysis based on the whole genome sequence further confirmed the bacterial taxonomy of EOBSR_19. Artificial experimental infection indicated that EOBSR_19 was pathogenic to fish. Antimicrobial susceptibility test showed it was multi-drug resistant. The EOBSR_19 was found to be resistant to 18 antibiotics belonging to quinolones, macrolides, sulfonamides, aminoglycosides, and β-lactams classes. The whole genome sequencing analysis showed that EOBSR_19 carried 730 virulence genes that were annotated for different functional modules, such as adhesion and invasion, secretion system, siderophore transport system and bacterial toxin. Among them, the virulence genes related to adhesion and invasion were the most abundant. In addition, drug resistance genes involved in multiple mechanisms of antimicrobial resistance were identified in its genomics, including multidrug resistance efflux pumps, antibiotic inactivating enzymes, and antibiotic binding site mutations. Its genomic analysis via whole-genome sequencing provided insights into the pathogenicity and antimicrobial resistance.

Rates of cerebrospinal fluid infection and the causative organisms following shunt procedures in Saudi Arabia. A retrospective study based on radiological findings

Objectives:

To assess the incidence of infection following various cerebrospinal fluid (CSF) shunt procedures among patients with hydrocephalus and related conditions, based on the age of the patient, and to determine the types of pathogens responsible for shunt infections.

Methods:

This retrospective single center study reviewed the records of patients with culture-confirmed CSF shunt infection diagnosed between January 2012 and December 2017. Cases without central nervous system imaging investigations were excluded.

Results:

The incidence rate of shunt-related infections was 32.2%. Among the 189 patients whose records were included, Staphylococcus epidermidis (47.5%) and Acinetobacter baumannii (18%) were the most common causative organisms. The incidence of postoperative infection was higher among those who underwent external ventricular drain procedures (65%) than among those who underwent ventriculoperitoneal shunt procedures (24%). There were no intraoperative deaths. However, the postoperative death rate was 12.2% during hospital stay (mean duration = 9 days); 2% of these deaths occurred after shunt removal.

Conclusion:

The incidence of infections after CSF shunt procedures was high in our tertiary academic hospital during the study period, compared to those reported in similar clinical settings and before developing a detailed standardized protocol for infection control. Although gram-negative organisms were the most prevalent cause of CSF infections, S. epidermidis (a gram-positive organism) was the most commonly encountered causative agent. Shunt protocols should be implemented to address perioperative shortcomings and to reduce overall mortality and morbidity.

Enterobacter spp.: Update on Taxonomy, Clinical Aspects, and Emerging Antimicrobial Resistance

The genus Enterobacter is a member of the ESKAPE group, which contains the major resistant bacterial pathogens. First described in 1960, this group member has proven to be more complex as a result of the exponential evolution of phenotypic and genotypic methods. Today, 22 species belong to the Enterobacter genus. These species are described in the environment and have been reported as opportunistic pathogens in plants, animals, and humans. The pathogenicity/virulence of this bacterium remains rather unclear due to the limited amount of work performed to date in this field. In contrast, its resistance against antibacterial agents has been extensively studied. In the face of antibiotic treatment, it is able to manage different mechanisms of resistance via various local and global regulator genes and the modulation of the expression of different proteins, including enzymes (β-lactamases, etc.) or membrane transporters, such as porins and efflux pumps. During various hospital outbreaks, the Enterobacter aerogenes and E. cloacae complex exhibited a multidrug-resistant phenotype, which has stimulated questions about the role of cascade regulation in the emergence of these well-adapted clones.

Bacterial isolation from internal organs of rats (Rattus rattus) captured in Baghdad city of Iraq

Aim

Rats are accused in disseminating many zoonotic diseases. This study aimed to isolate and identify bacteria from internal organs of rats captured in Baghdad City, Iraq.

Materials and Methods

A total of 120 black rats (R. rattus) were trapped from different areas in Baghdad city. Rats were kept in individual plastic cages for 3 h before euthanizing. Deep pharyngeal swab, intestinal content, urine, and pieces of the liver and spleen, lung, kidney, and brain were obtained aseptically. The specimens were inoculated into peptone water and incubated at 37°C for 24 h for enrichment. A loopful of each specimen was then subcultured onto MacConkey Agar, Blood Agar, and Mannitol Salt Agar. CHROMagar O157 H7 and CHROMagar Listeria were used to detect Escherichia coli 157:7 and Listeria spp., respectively. Biochemical tests on analytical profile index, microscopic examination, and commercial kit for latex agglutination test for serotyping E. coli O157:H7 were used.

Results

Mixed bacterial isolates were recorded as 116, 52, 36, 28, 18, 6, and 4 from intestinal contents, deep pharyngeal, liver and spleen, urine, lung, brain, and kidney, respectively. Microorganisms included E. coli, Staphylococcus aureus, Streptococcus spp., Bacillus spp., Pseudomonas aeruginosa, Citrobacter freundii, Proteus vulgaris, E. coli O157:H7, Enterobacter cloacae, Listeria spp., Klebsiella spp., Ochrobactrum anthropi, Aeromonas spp., Brucella spp., Pseudomonas fluorescens, Escherichia fergusonii, Micrococcus spp., Morganella spp., Proteus mirabilis, Pseudomonas luteola, and Streptobacillus spp. The highest bacterial prevalence (88; 73.33%) was recorded for E. coli, where 68 isolates were identified from the intestinal contents. Of these, four isolates were E. coli O157:H7.

Conclusion

Rats are important carriers and transmitters of a number of pathogens and can disseminate these microorganisms to humans and animals.

An Ultrasound Imaging-Guided Robotic HIFU Ablation Experimental System and Accuracy Evaluations

In recent years, noninvasive thermal treatment by using high-intensity focused ultrasound (HIFU) has high potential in tumor treatment. The goal of this research is to develop an ultrasound imaging-guided robotic HIFU ablation system for tumor treatment. The system integrates the technologies of ultrasound image-assisted guidance, robotic positioning control, and HIFU treatment planning. With the assistance of ultrasound image guidance technology, the tumor size and location can be determined from ultrasound images as well as the robotic arm can be controlled to position the HIFU transducer to focus on the target tumor. After the development of the system, several experiments were conducted to measure the positioning accuracy of this system. The results show that the average positioning error is 1.01 mm with a standard deviation 0.34, and HIFU ablation accuracy is 1.32 mm with a standard deviation 0.58, which means this system is confirmed with its possibility and accuracy.