Occurrence, Antimicrobial Resistance, and Virulence Profiles of Salmonella Serovars Isolated from Wild Reptiles in South Africa.

Reptiles are carriers of an array of microorganisms, including significant zoonotic bacteria of the genus Salmonella, which cause a disease referred to as salmonellosis that affects both animals and humans. This study investigated the occurrence of Salmonella serovars in wild reptiles at Timbavati Private Game Reserve in Limpopo Province, South Africa, and examined their virulence and antimicrobial resistance gene profiles. A total of 19 wild reptiles were sampled, which resulted in 30 presumptive Salmonella isolates. The isolates were identified using polymerase chain reaction (PCR) by amplifying the invA gene and were further confirmed by 16S rRNA gene sequencing. Salmonella serovars were detected in chameleons (36.8%), lizards (31.6%), snakes (15.8%), and tortoises (15.8%). The use of 16S rRNA gene sequencing revealed that Salmonella enterica subsp. enterica serovar Salamae (30%), S. enterica subsp. enterica (16.7%), S. enterica subsp. enterica serovar Typhimurium (13.3%), and S. enterica subsp. enterica serovar Indiana (13.3%) were the four most common subspecies among the investigated 30 isolates. Detected virulence genes included pagN (100%), hilA (96.7%), ssrB (96.7%), prgH (86.7%), and marT (86.7%). The isolates exhibited resistance to nalidixic acid (43.3%) and kanamycin (43.3%), followed by streptomycin (16.7%) and ciprofloxacin (3.3%). Antibiotic-resistant genes were detected as follows: strA, strB, qnrA, qnrS, parC, aadA, aac(6')-Ib, and aac(6')-Ib-cr at 33.3%, 6.7%, 16.7, 13.3%, 10%, 23.3%, 6.7%, and 10%, respectively. The findings highlight the necessity of educational initiatives aimed at reducing reptile-related infections. Effective antibiotic treatment appears promising for infection, given the minimal drug resistance observed in reptile Salmonella serovars in the current study.

Never smile at a crocodile: Gaping behaviour in the Nile crocodile at Ndumo Game Reserve, South Africa.

Gaping is a regularly observed behaviour in crocodilians globally but is still poorly understood in relation to external variables which could trigger this behaviour. The occurrence of gaping behaviour was investigated in a large wild population of Nile crocodiles (Crocodylus niloticus) during the dry and wet seasons at Nyamithi Pan, Ndumo Game Reserve, South Africa. This is one of the longest crocodile gaping behaviour studies conducted in the wild, with 300 h of observations conducted over two seasons resulting in 1120 gaping behaviours recorded. The most common size class observed was between 1.5 and 2.5 m (n = 697), which accounted for 62.2% of the gaping observations. A significant decrease in gaping duration was observed as ambient temperatures increased, and the gape duration was longer at a higher degree angle. In addition, an increase in gape duration was observed as the number of neighbouring crocodiles increased. These results suggest gaping behaviour occurs when there are other crocodiles nearby and when temperatures do not necessitate thermoregulation. The study suggests that gaping could be used as a form of thermoregulation and intra-species communication.

Developmental life stages of the Pickersgill's reed frog (Hyperolius pickersgilli) in an ex-situ environment at Johannesburg Zoo's captive breeding facility, South Africa.

Globally, the threats of habitat loss and disease on amphibian survival have necessitated the creation of ex-situ insurance populations as a conservation tool. We initiated a captive breeding project to create an insurance population for the endangered Pickersgill's reed frog (Hyperolius pickersgilli Raw, 1982) at the Johannesburg Zoo from parents collected from KwaZulu-Natal Province, South Africa, in 2017. We found that this species has seven developmental life stages, each with unique management requirements. The quiescent tadpoles hatched 6-8 days after the eggs were laid and remained at this stage for 2 days. The next stage, the developing tadpoles, showed no form of cannibalism or carrion feeding. The external appearance of the first leg (the right hind) occurred 5-6 weeks after the tadpoles hatched, and the metamorph stage was reached after 7-8 weeks. The metamorph stage lasted 3-5 days, after which tail resorption was complete and the froglet stage reached. Froglets could not be sexed externally, although body color changed based on the amount of light present at the resting place. Sub-adults were 6 months and older with adult coloration and sex differentiation visible even with color change. Adults were older than 18 months and fully developed and sexually mature, displaying amplexus, oviposition, and external fertilization. A greater understanding of Pickersgill's reed frog's developmental stages and physiological and environmental needs can improve captive breeding and subsequent release of the frogs, facilitate captive breeding elsewhere, and improve the species' conservation status.

Modification of the third phase in the framework for vertebrate species persistence in urban mosaic environments.

Urbanisation is rapidly transforming natural landscapes with consequences for biodiversity. Little is documented on the response of African wildlife to urbanisation. We reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa to determine trends. Connected habitat mosaics of natural and anthropogenic green spaces are critical for urban wildlife persistence. We present a novel modification to the final of three phases of the framework described by Evans et al. (2010), which documents this sequence for vertebrate species persistence, based on the perspective of our research. Species in suburbia exhibit an initial phase where behavioural and ecological flexibility, life-history traits and phenotypic plasticity either contribute to their success, or they stay at low numbers. Where successful, the next phase is a rapid increase in populations and distribution; anthropogenic food resources and alternate breeding sites are effectively exploited. The modified third phase either continues to spread, plateau or decline.