Analysis of the effects of storage temperature and contamination on aerobic bacterial culture results of bronchoalveolar lavage fluid

Microbiome and floral associations of a wild bee using biodiversity survey collections

The health of bees can be assessed through their microbiome, which serves as a biomarker indicating the presence of both beneficial and harmful microorganisms within a bee community. This study presents the characterisation of the bacterial, fungal, and plant composition on the cuticle of adult bicoloured sweat bees (Agapostemon virescens). These bees were collected using various methods such as pan traps, blue vane traps and sweep netting across the northern extent of their habitat range. Non-destructive methods were employed to extract DNA from the whole pinned specimens of these wild bees. Metabarcoding of the 16S rRNA, ITS and rbcL regions was then performed. The study found that the method of collection influenced the detection of certain microbial and plant taxa. Among the collection methods, sweep net samples showed the lowest fungal alpha diversity. However, minor differences in bacterial or fungal beta diversity suggest that no single method is significantly superior to others. Therefore, a combination of techniques can cater to a broader spectrum of microbial detection. The study also revealed regional variations in bacterial, fungal and plant diversity. The core microbiome of A. virescens comprises two bacteria, three fungi and a plant association, all of which are commonly detected in other wild bees. These core microbes remained consistent across different collection methods and locations. Further extensive studies of wild bee microbiomes across various species and landscapes will help uncover crucial relationships between pollinator health and their environment.

Intestinal dehiscence and mortality in cats undergoing gastrointestinal surgery

OBJECTIVES

The aim of this study was to determine the incidence of and risk factors for both gastrointestinal (GI) incisional dehiscence and mortality in a large cohort of cats undergoing GI surgery. We hypothesized that cats with preoperative septic peritonitis (PSP), systemic inflammatory response syndrome (SIRS) or sepsis would have higher GI dehiscence and mortality rates than unaffected cats.

METHODS

A medical records search identified cats with surgically created, full-thickness incisions into their stomach, small intestines or large intestines. Preoperative data, including signalment, clinical signs, comorbidities, surgical history, current medications, presenting physical examination findings, complete blood counts and serum biochemistry values, were collected. It was determined whether or not cats had PSP, SIRS or sepsis at admission. Intraoperative data, final diagnosis and postoperative variables such as vital parameters, bloodwork and (if applicable) the development of GI dehiscence or mortality were noted. Postoperative follow-up of at least 10 days was obtained in survivors.

RESULTS

In total, 126 cats were included. One cat developed GI dehiscence following complete resection of a jejunal adenocarcinoma. Twenty-three cats (18.2%) died within 10 days of surgery. Cats with PSP (P = 0.0462) or that developed hypothermia 25-72 h postoperatively (P = 0.0055) had higher odds of mortality in multivariate analysis. Cats with PSP had 6.7-times higher odds of mortality than cats not diagnosed with PSP.

CONCLUSIONS AND RELEVANCE

In cats receiving GI surgery, the incidence of GI incisional dehiscence was <1%. Cats with PSP had a higher likelihood of mortality. SIRS was a common finding in cats with septic peritonitis, but was not associated with mortality. Postoperative mortality during the home recovery period might be significant in cats. Future studies evaluating postoperative mortality in cats should consider extending the research period beyond the date of discharge.

Association between quantitative bacterial culture of bronchoalveolar lavage fluid and antibiotic requirement in dogs with lower respiratory tract signs

BACKGROUND

Historically, positive bacterial cultures from the lower respiratory tract (LRT) have been considered clinically relevant when quantitative bacterial cultures of bronchoalveolar lavage fluid (BALF) were >1700 colony forming units (cfu)/mL. However, this threshold might not accurately predict a requirement for antibiotics.

OBJECTIVES

To study whether quantitative BALF bacterial culture results were predictive of antibiotic requirement in dogs with LRT signs.

ANIMALS

Thirty-three client-owned dogs.

METHODS

Cross-sectional study. Dogs with positive quantitative bacterial culture of BALF were included. Dogs were divided into 2 groups, depending on whether they had a LRT infection requiring antibiotics (LRTI-RA) or LRT disease not requiring antibiotics (LRTD-NRA), based on thoracic imaging features, presence of intracellular bacteria on BALF cytology, and response to treatment. Predictive effect of cfu/mL and BALF total nucleated cell count (TNCC) on antibiotic requirement, adjusting for ongoing or prior antibiotic therapy and age, were studied using logistic regression.

RESULTS

Twenty-two and 11 dogs were included in the LRTI-RA and LRTD-NRA groups, respectively. The cfu/mL was not significantly predictive of antibiotic requirement, independent of ongoing or prior antibiotic treatment and age (LRTI-RA: median, 10 000 cfu/mL; range, 10-3 × 108 ; LRTD-NRA: median, 10  000 cfu/mL; range, 250-1.3 × 109 ; P = .27). The TNCC was not significantly predictive of antibiotic requirement when only dogs with bronchial disease were considered (LRTI-RA: median, 470 cells/μL; range, 240-2260; LRTD-NRA: median, 455 cells/μL; range, 80-4990; P = .57).

CONCLUSION AND CLINICAL IMPORTANCE

The cfu/mL is an inappropriate measure for determining whether antibiotics are of benefit in dogs with LRT signs.

Analysis of the effects of storage temperature and contamination on aerobic bacterial culture results of bronchoalveolar lavage fluid

BACKGROUND

Storage temperature of bronchoalveolar lavage fluid (BALF) impacts cytological evaluation. The effect of storage temperature before bacterial culture has not been evaluated.

OBJECTIVES

To assess whether BALF storage temperature alters aerobic bacterial culture results.

ANIMALS

Eight healthy, male, intact, purpose-bred Beagles.

METHODS

Prospective, controlled investigation. Samples of BALF were collected sterilely. Half of each sample was reserved for controls, and half was inoculated with 10⁴ colony forming units per milliliter (cfu/mL) Bordetella bronchiseptica and 10² cfu/mL Escherichia coli. Control and inoculated samples each were separated into 4 aliquots (1 plated immediately; 3 stored at 4, 24, or 37°C, respectively, for 24 hours before aerobic bacterial culture). Colony counts were compared across treatments for each organism.

RESULTS

In inoculated samples, a statistical difference could not be detected in growth of E. coli or B. bronchiseptica between the baseline culture and BALF stored at 4°C for 24 hours before culture. However, for E. coli, growth in cfu/mL at both 24 and 37°C was higher compared to baseline (P < .05) and compared to 4°C (P < .05). For B. bronchiseptica cfu/mL, growth at 37°C was significantly different (P = .003) compared to both baseline and 4°C.

CONCLUSIONS AND CLINICAL IMPORTANCE

Samples of BALF may be stored at 4°C for 24 hours before culture without substantially altering culture results. Inappropriate storage or shipment temperature (room temperature or exposure to heat) can result in overgrowth of E. coli or B. bronchiseptica, which could alter clinical decisions.