A wide spectrum of fastidious and ampicillin-susceptible bacteria dominate in animal-caused wounds

Characteristics of gallbladder microbiome in healthy dogs and cats, dogs with gallbladder mucocele, and cats with suspected cholangitis/cholangiohepatitis

The aim of this study was to investigate and characterize the microbiome in bile samples obtained from dogs with gallbladder mucocele (6), cats with suspected cholangitis/cholangiohepatitis (4), as well as from healthy dogs (6) and cats (4). Our goal was to compare the microbiome patterns with clinical findings and bacterial culture results in diseases of the gallbladder and to identify a potential microbial biomarker of diseased groups. The microbial taxa composition revealed that Proteobacteria were the most dominant phylum in healthy and diseased individuals in all groups. Individuals from six families including Burkholderiaceae, Phyllobacteriaceae, Bradyrhizobiaceae, Sphingomonadaceae, Moraxellaceae, and Caulobacteraceae, constituted the core microbiome in the gallbladder of healthy dogs. A combination of LEfSe analysis and Taxa2ASV decomposer revealed that Pseudomonaceae and Ruminococcaceae exclusively occurred in the mucocele group. In conclusion, this study determined the core microbiome in the gallbladder of healthy dogs and the possible biomarkers (Pseudomonaceae and Ruminococcaceae) of gallbladder mucocele in dogs.

The potential for the double risk of rabies and antimicrobial resistance in a high rabies endemic setting: detection of antibiotic resistance in bacterial isolates from infected dog bite wounds in Uganda

BACKGROUND

Post-exposure treatment for dog bites in humans aims at alleviating the risk of rabies and promoting wound healing. Wound healing may be complicated by bacteria. This study identified the different bacteria and their antibiotic susceptibilities in infected dog bite wounds (DBWs) in Uganda.

METHODS

A cross-sectional study was conducted among 376 dog bite patients. Wound swabs from patients with infected DBWs were collected and inoculated into recommended media. They were cultured for both aerobic and anaerobic bacteria. All isolated bacteria were identified based on colony characteristics, gram stain, and standard biochemical tests. Molecular identification was performed for strains that were resistant to three or more antibiotics. Antibiotic susceptibility testing was conducted using the disc diffusion method following the modified Kirby-Bauer method. The data were analysed using Stata version 15 software.

RESULTS

Approximately half of the patients (52.9%, 199/376) presented with infected wounds. Majority of the swabs (84.4%, 168/199) were culture positive, and yielded a total of 768 isolates where about half (52.9%, 406/768) were gram positive bacteria, and about two-thirds (64.6%, 496/768) were recovered from category II wounds. Among the gram positive bacteria, 339 (83.5%) were aerobes where Staphylococcus aureus (103, 30.4%), Coagulase-negative staphylococci (68, 20.1%), and Corynebacterium spp (33, 9.7%) had the highest prevalence. For the 362 Gram negative isolates, 217 (59.9%) were aerobes and the commonest isolates were P. maltocida (64, 29.5%), Capnocytophaga canimorsus (36, 16.6%) and P. canis (26, 12.0%). Gram-positive isolates were resistant to metronidazole (93.6%), oxacillin (68.5%), ceftriaxone (14.6%) and amoxicillin/clavulanic acid (14.0%). Gram negative isolates were resistant to metronidazole (100%), ampicillin (30.7%), oxacillin (29.3%), and doxycycline (22.9%). Multidrug resistance was in 105 (29.0%) and 121/406 (29.8%) of the gram-negative and gram-positive isolates, respectively. All gram-positive isolates were susceptible to vancomycin and ciprofloxacin.

CONCLUSIONS

Infection rates of DBWs in Uganda are high and the dominant bacterial isolates are Staphylococcus aureus, Pasteurella spps, and Capnocytophaga canimorsus. Multidrug resistance to commonly used antibiotics is high. The recommendation in the Uganda Clinical Guidelines to use metronidazole in the management of DBWs should be reviewed. DBWs should be enlisted for routine antimicrobial resistance surveillance and rational use of antimicrobial agents should be promoted.

Biting the hand that feeds you: Management of human and animal bites

Bites from animal and humans represent a very small proportion of all the patients presenting to emergency departments, However, they require prompt medical and surgical intervention in order to minimise the risk of infection, that may lead to limb and life-threatening complications. In this review article we synthesise the existing literature for treatment of human and animal bites and offer practical considerations when managing bite injuries.

Canibacter oris - a fairly unknown pathogenic agent of bite wound infections

Here, we report on the second case of bite wound infection by Canibacter oris. This bacterium belongs to the family of Microbacteriaceae in the order of Microbacterales in the class of Actinobacteria, which are prevalent in the oral flora. Possibly this bacterium has been overlooked until now, because it cannot be recognized by conventional differentiation methods. MALDI-TOF as well as PCR are able to identify this pathogen.