Absence of bovine leukemia virus in the buffy coats of breast cancer cases from Alabama, USA.

Breast cancer is reported as one of the most common and deadly cancers among females. Recent findings have suggested that bovine leukemia virus (BLV), a highly prevalent bovine virus worldwide, might be linked to human breast cancer. However, the involvement of BLV as a risk factor for breast cancer remains controversial. In this study, BLV FRET-PCR was carried out on 238 blood-derived DNA samples from breast cancer patients from the Alabama Hereditary Cancer Cohort. In addition, randomly selected samples (n = 20) were evaluated by WGS for the presence of BLV genome. No BLV proviral DNA was detected in any of 238 samples assayed by FRET-qPCR in this study. Similarly, the WGS analysis did not detect the presence of the BLV genome in the DNA of the buffy coats from 20 randomly selected patients with breast cancer. This study did not support the findings of suggesting an association between BLV and breast cancer. Notably, nearly all the studies using in situ PCR and immunohistochemistry demonstrated positive associations while other studies using whole-genome sequencing and other methods failed to identify the BLV association with breast cancer. Further studies including all reported BLV detection techniques/methods on the same breast cancer sample sets would appear to be the most likely way of resolving the current contradictory evidence.

Antibodies to SARS-CoV-2 in dogs and cats, USA.

To provide more complete data on SARS-CoV-2 infections in dogs and cats in the U.S., we conducted a serosurvey on convenience serum samples from dogs (n=1336) and cats (n=956) collected from 48 states of the USA in 2020. An ELISA targeting the antibody against nucleocapsid identified eleven positive and two doubtful samples in cats, and five positive and five doubtful samples in dogs. A surrogate neutralization assay detecting antibodies blocking the attachment of the spike protein to ACE2 was positive with three of the ELISA positive and doubtful samples, and one of 463 randomly selected ELISA negative samples. These four positive samples were confirmed by SARS-CoV-2 virus neutralization testing. All were from cats, in New York, Florida, and New Jersey (n=2). The serosurvey results, one of the largest yet completed on dogs and cats globally, support the OIE and CDC positions that currently there is no evidence that pets play a role in the spread of SARS CoV-2 in humans.

Concurrent Resistance to Carbapenem and Colistin Among Enterobacteriaceae Recovered From Human and Animal Sources in Nigeria Is Associated With Multiple Genetic Mechanisms.

Resistance to last resort drugs such as carbapenem and colistin is a serious global health threat. This study investigated carbapenem and colistin resistance in 583 non-duplicate Enterobacteriaceae isolates utilizing phenotypic methods and whole genome sequencing (WGS). Of the 583 isolates recovered from humans, animals and the environment in Nigeria, 18.9% (110/583) were resistant to at least one carbapenem (meropenem, ertapenem, and imipenem) and 9.1% (53/583) exhibited concurrent carbapenem-colistin resistance. The minimum inhibitory concentrations of carbapenem and colistin were 2-32 µg/mL and 8 to >64 µg/mL, respectively. No carbapenem resistant isolates produced carbapenemase nor harbored any known carbapenemase producing genes. WGS supported that concurrent carbapenem-colistin resistance was mediated by novel and previously described alterations in chromosomal efflux regulatory genes, particularly mgrB (M1V) ompC (M1_V24del) ompK37 (I70M, I128M) ramR (M1V), and marR (M1V). In addition, alterations/mutations were detected in the etpA, arnT, ccrB, pmrB in colistin resistant bacteria and ompK36 in carbapenem resistant bacteria. The bacterial isolates were distributed into 37 sequence types and characterized by the presence of internationally recognized high-risk clones. The results indicate that humans and animals in Nigeria may serve as reservoirs and vehicles for the global spread of the isolates. Further studies on antimicrobial resistance in African countries are warranted.

Molecular and Serological Prevalence of Leptospira spp. in Feral Pigs (Sus scrofa) and their Habitats in Alabama, USA.

Leptospirosis is a widespread zoonosis and has been recognized as a re-emerging infectious disease in humans and a variety of wild and domestic animal species. In order to understand the prevalence and diversity of Leptospira spp. in feral pig populations of Alabama, we trapped 315 feral pigs in Bullock County east-central Alabama, and collected 97 environmental samples from riparian areas in Bullock County and Macon County east-central Alabama. Two previously published PCRs followed by DNA sequencing and BLASTn were performed to identify pathogenic Leptospira species in the kidney of feral pigs (3.2%, 10/315) as well as environmental samples collected from the habitats of feral pigs (2.1%, 2/97), but not in the whole blood samples (n = 276) or spleen (n = 51). An ELISA determined that 44.2% of serum samples (122/276) were antibody-positive for Leptospira. The identification of two pathogenic Leptospira species from environmental samples and the high sero-positivity in feral pigs suggests potential pathogen shedding from feral pigs to environments, and to humans and domestic animals. In order to better understand the risk to human health associated with feral swine presence, further studies are warranted to explore the interrelationship between Leptospira spp. shedding in the urine of feral pigs and bacterial culture to explore pathogenicity. Multi-locus sequencing typing (MLST) and microscopic agglutination tests (MAT) should be performed in future studies to make a definite determination of pathogenic Leptospira in feral pigs in Alabama.

Comparison of microbiota, antimicrobial resistance genes and mobile genetic elements in flies and the feces of sympatric animals.

Flies are well-known vectors of bacterial pathogens, but there are little data on their role in spreading microbial community and antimicrobial resistance. In this study, we compared the bacterial community, antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs) in flies with those in the feces of sympatric animals. A 16S rRNA-based microbial analysis identified 23 bacterial phyla in fecal samples and 25 phyla in flies; all the phyla identified in the fecal samples were also found in the flies. Bray-Curtis dissimilarity analysis showed that the microbiota of the flies were more similar to the microbiota of the feces of their sympatric animals than those of the feces from the three other animal species studied. The qPCR array amplified 276 ARGs/MGEs in fecal samples, and 216 ARGs/MGEs in the flies, while 198 of these genes were identified in both flies and feces. Long-term studies with larger sample numbers from more geospatially distinct populations and infection trials are indicated to further evaluate the possibility of flies as sentinels for antimicrobial resistance.

Identification of mobile colistin resistance genes (mcr-1.1, mcr-5 and mcr-8.1) in Enterobacteriaceae and Alcaligenes faecalis of human and animal origin, Nigeria.

Colistin is a last-resort drug used to treat infections caused by multidrug-resistant Gram-negative bacteria that have developed carbapenem resistance. Emergence and rapid dissemination of the nine plasmid-mediated mobile colistin resistance genes (mcr-1 to mcr-9) has led to fear of pandrug-resistant infections worldwide. To date, there is only limited information on colistin resistance in African countries where the drug is widely used in agriculture. In this Nigerian study, 583 non-duplicate bacterial strains were isolated from 1119 samples from humans, camels, cattle, dogs, pigs and poultry using colistin-supplemented MacConkey agar, among which 17.0% (99/583) were colistin-resistant. PCR (mcr-1 to mcr-9) and whole-genome sequencing (WGS) identified mcr in 21.2% (21/99) of colistin-resistant isolates: mcr-1.1 (n = 13), mcr-8.1 (n = 5), mcr-1.1 and mcr-8.1 (n = 2), and mcr-1.1 and mcr-5 (n = 1). Of the 21 mcr-positive strains, 9 were isolated from human samples, with 8 being Klebsiella pneumoniae, and 6 of these human K. pneumoniae had a high colistin MIC (>64 µg/mL). In contrast, 9 of the 12 mcr-positive animal isolates were Escherichia coli, of which only 2 had a colistin MIC of >64 µg/mL. This study is the first to report mcr-1 in Alcaligenes faecalis and the emergence of mcr-5 and mcr-8 in Nigeria. WGS determined that mcr-1 was localised on an IncX4 plasmid and that 95.2% of mcr-1 harbouring isolates (20/21) transferred colistin resistance successfully by conjugation. These findings highlight the global spread of colistin resistance and emphasise the urgent need for co-ordinated global action to combat resistant bacteria.

Peptide ELISA and FRET-qPCR Identified a Significantly Higher Prevalence of Chlamydia suis in Domestic Pigs Than in Feral Swine from the State of Alabama, USA.

Chlamydia suis is an important, highly prevalent, and diverse obligate intracellular pathogen infecting pigs. In order to investigate the prevalence and diversity of C. suis in the U.S., 276 whole blood samples from feral swine were collected as well as 109 fecal swabs and 60 whole blood samples from domestic pigs. C. suis-specific peptide ELISA identified anti-C. suis antibodies in 13.0% of the blood of feral swine (26/276) and 80.0% of the domestic pigs (48/60). FRET-qPCR and DNA sequencing found C. suis DNA in 99.1% of the fecal swabs (108/109) and 21.7% of the whole blood (13/60) of the domestic pigs, but not in any of the assayed blood samples (0/267) in feral swine. Phylogenetic comparison of partial C. suis ompA gene sequences and C. suis-specific multilocus sequencing typing (MLST) revealed significant genetic diversity of the C. suis identified in this study. Highly genetically diverse C. suis strains are prevalent in domestic pigs in the USA. As crowding strongly enhances the frequency and intensity of highly prevalent Chlamydia infections in animals, less population density in feral swine than in domestic pigs may explain the significantly lower C. suis prevalence in feral swine. A future study is warranted to obtain C. suis DNA from feral swine to perform genetic diversity of C. suis between commercial and feral pigs.

Non-puerperal induced lactation: an infant feeding option in paediatric HIV/AIDS in tropical Africa.

A major problem in the management of infants exposed to HIV is the issue of feeding, which stems from the need to avoid transmission of the virus via breast milk. Other important issues in the nutrition of infants exposed to the virus include severe maternal illness, which makes suckling extremely difficult, and feeding orphans. Wet nursing is one of the recommended steps in addressing the feeding problems of such infants but for reasons of sociocultural disapproval, it appears not to be popular in traditional African settings. Non-puerperal induced lactation or re-lactation of a close relation, usually a grandmother, which hitherto has been used to rehabilitate severely malnourished motherless infants, may be equally useful. The procedure of re-lactation and the limitations of the method are highlighted. Also, the need to employ information, education and communication in improving the sociocultural acceptability of this veritable infant feeding method in tropical Africa is discussed.

Evaluating and managing neonatal acute renal failure in a resource-poor setting.

Acute renal failure (ARF) is encountered in neonatal care where it may be associated with significant morbidities. Pre-renal failure, which is due to impaired renal tissue perfusion, is the commonest type of ARF. It is amenable to treatment with excellent prognosis following prompt diagnosis and timely institution of appropriate intervention. Unfortunately, ARF in the newborn is usually asymptomatic and it is only suspected when a newborn infant has not been observed to pass urine over several hours or when serum Creatinine is observed to be elevated or rising. In resource-poor settings, it is often difficult to conduct detailed evaluation of suspected cases of newborn ARF due to lack of appropriate equipments and infrastructure. Similarly, therapeutic facilities are sparse and there is heavy reliance on conservative management of cases. Such difficulties encountered in the evaluation and management of newborns with ARF in most parts of the developing world, like Nigeria, where diagnostic and therapeutic facilities are limited are highlighted.