Genevieve McKew

Isolation and plasmid characterization of carbapenemase (IMP-4) producing Salmonella enterica Typhimurium from cats

Carbapenem-resistant Enterobacteriaceae (CRE) are a pressing public health issue due to limited therapeutic options to treat such infections. CREs have been predominantly isolated from humans and environmental samples and they are rarely reported among companion animals. In this study we report on the isolation and plasmid characterization of carbapenemase (IMP-4) producing Salmonella enterica Typhimurium from a companion animal. Carbapenemase-producing S. enterica Typhimurium carrying blaIMP-4 was identified from a systemically unwell (index) cat and three additional cats at an animal shelter. All isolates were identical and belonged to ST19. Genome sequencing revealed the acquisition of a multidrug-resistant IncHI2 plasmid (pIMP4-SEM1) that encoded resistance to nine antimicrobial classes including carbapenems and carried the blaIMP-4-qacG-aacA4-catB3 cassette array. The plasmid also encoded resistance to arsenic (MIC-150 mM). Comparative analysis revealed that the plasmid pIMP4-SEM1 showed greatest similarity to two blaIMP-8 carrying IncHI2 plasmids from Enterobacter spp. isolated from humans in China. This is the first report of CRE carrying a blaIMP-4 gene causing a clinical infection in a companion animal, with presumed nosocomial spread. This study illustrates the broader community risk entailed in escalating CRE transmission within a zoonotic species such as Salmonella, and in a cycle that encompasses humans, animals and the environment.

Severe Sepsis Due to Chryseobacterium indologenes in an Immunocompetent Adventure Traveler

ABSTRACT Chryseobacterium indologenes is an environmental organism which is usually an opportunistic pathogen, most usually associated with nosocomial or device-related infections. This case, affecting a fit and well adventure traveler, demonstrates that it may be an agent of severe sepsis in otherwise healthy humans.

Probable contaminants no more: rapid identification of Gram-positive rods leads to improved clinical care.

Previously, identification to the species level of “nonsignificant” bacteria (e.g., single specimens with Gram-positive rods or coagulase-negative staphylococci) was generally not performed in our laboratory, including for blood culture isolates. Reasons for this included the low pretest

Actinomyces cavernous sinus infection: a case and systematic literature review

A 63-year-old man presented with a 2-month history of progressive right-sided exophthalmos, painful ophthalmoplegia and fevers. As more features developed, he was diagnosed with giant cell arteritis, then Tolosa-Hunt syndrome, and transiently responded to corticosteroids. A bland cerebrospinal fluid and highly metabolically active brain (18F)-fluoro-D-glucose-positron emission tomography suggested lymphoma. Biopsy of the mass showed sulphur granules with Gram-positive filamentous bacteria with Actinomyces-like colonies. Actinomyces cavernous sinus infections are rare and indolent. They often mimic non-infective causes including other inflammatory and infiltrative conditions, vascular and neoplastic causes, particularly lymphoma. Clinicians should consider infective cavernous sinus syndromes in people with a fluctuating painful ophthalmoplegia that responds poorly to corticosteroids. The term Tolosa-Hunt syndrome is problematic and should be retired or used only with reservation.

Nocardia Septic Arthritis Complicating an Anterior Cruciate Ligament Repair

ABSTRACT Nocardia infection following anterior cruciate ligament (ACL) allograft reconstruction is a rare occurrence. We report a case of Nocardia infection of an allograft ACL reconstruction and septic arthritis of the knee joint due to an organism most similar to the novel Nocardia species Nocardia aobensis.

Streptococcus Pneumoniae Causing Intra-abdominal and Pelvic Infection: A Case Series

Streptococcus pneumoniae is a pathogen known to cause pneumonia, sinusitis, meningitis, and otitis media, but is overlooked as a pathogen causing gastrointestinal illness. We report four cases of Streptococcus pneumoniae causing intra-abdominal and pelvic infection. Streptococcus pneumoniae should be considered in the setting of intra-abdominal infection, especially in patients with risk factors for invasive pneumococcal disease or with a concomitant respiratory infection at presentation.

Do the eyes have it? Performance of molecular detection of tuberculosis on fresh and paraffin embedded tissues, including those with no visible tissue

Background Little has been published on the performance of tuberculosis PCR with respect to the quality of tissue specimens. Laboratories often receive liquid samples from fine-needle aspirates with no visible tissue for testing. The sensitivity of tuberculosis (TB) PCR on these specimens is unknown. Methods TB PCR was compared to culture or a combination of clinical and histopathological evidence of tuberculosis; a separate analysis excluded patients with current or previous treatment. Results Sixty-five patients had 81 positive samples; 69 by PCR and 43 by culture. Excluding those on treatment, 51 of 57 (89%) were PCR positive versus 43 of 61 (70%) by culture. 44 samples had ‘no visible tissue’ noted. Five were PCR positive; only one was culture positive. At least two samples were falsely negative. Conclusions Sensitivity of TB PCR is superior to culture on tissue. Five of seven TB cases with no visible tissue were PCR positive. The quality of the specimen deserves comment, as the two (5%) known false negatives are of concern.

Identification of burkholderia cepacia complex and other gram negative bacteria from cystic fibrosis sputa: a comparison of mass/charge protein spectroscopy and sequencing of housekeeping genes

Aim: Identification of Burkholderia cepacia complex (BCC) from cystic fibrosis sputa has significant prognostic and treatment implications for patients. Current methods for BCC and other non-fermenting Gram-negative bacilli (NFGNBs) involve sequencing the recA or 16 s rRNA genes, which is costly and time-consuming. Similarities between members of the BCC might limit the utility of mass/charge protein spectroscopy (MALDITOF) identification. Developing a local database of BCC MALDITOF spectra may improve its utility for identification of local isolates. Methods: 55 BCC isolates and 27 NFGNBs were collected from cystic fibrosis sputa from adult and paediatric patients. They were identified by recA or 16 s gene sequencing and comparison to GenBank sequences. Protein spectra were created after formic acid extraction of 24-hour colonies. Pre- and post-extraction spectra were identified with reference to the Bruker MALDITOF database. The post-extraction spectra were stored in a local library for reference. Results: The agreement between recA and 16 s sequencing and MALDITOF identification for genus, species and genomovar is reported. Discussion and Conclusion: It is likely that MALDITOF can be relied on to make a presumptive identification for empiric treatment and infection control purposes, but it remains to determine whether it is reliable enough to identify BCC members to genomovar level. I recommend that spectra of future isolates are compared against the local database as well as the Bruker database.