First Report of Antimicrobial Susceptibility and Virulence Gene Characterization Associated with Staphylococcus aureus Carriage in Healthy Camels from Tunisia

Abstract

A total of 318 nasal and rectal swabs were collected from 159 apparently healthy camels (Camelus dromedarius) randomly selected from five regions in southern and central Tunisia and screened for Staphylococcus aureus carriage. Staphylococcus spp. were recovered from 152 of 159 camels studied (95.6%) and in total 258 swabs (81%) were positive. Among these isolates, 16 were coagulase positive Staphylococcus (CoPS) (6.2%) and were characterized by biochemical and molecular tests as S. aureus. These were isolated from 14 camels (8.8%) with co-carriage in nasal and rectal mucosa by two camels. All S. aureus isolates recovered were methicillin-susceptible Staphylococcus aureus (MSSA) and were characterized by spa typing and PFGE. Three different spa types were recovered: t729, t4013 and a spa type newly registered as t19687, which was the most common. PFGE analysis revealed seven different patterns and these were characterized by MLST, which revealed five different sequence types (ST6, ST88, ST3583 and two new sequences, ST6504 and ST6506). All isolates harbored different virulence genes, including hld, encoding delta hemolysin; lukE–lukD, encoding bicomponent leukotoxin LukE–LukD; the clfB gene, encoding clumping factor B; the laminin gene, encoding laminin-binding protein; and cap8, encoding capsule type 8. Fifteen isolates harbored hemolysin beta (hlb) and fourteen encoded hemolysin alpha (hla) and hemolysin G2 (hlgv). Adhesin factors, including clfA and fnbB, were detected in five and four isolates respectively. Binding proteins, including collagen (cbp) and elastin-binding protein (ebp), were detected in two S. aureus isolates while fibrinogen-binding protein (fib) was identified in four isolates. This study provides the first set of genotyping data on the population structure and presence of toxin genes of S. aureus strains in Tunisian camels.

Prevalence and Molecular Characterization of Methicillin-Resistant Staphylococci (MRS) and Mammaliicocci (MRM) in Dromedary Camels from Algeria: First Detection of SCCmec-mecC Hybrid in Methicillin-Resistant Mammaliicoccus lentus

“…The CPS group is commonly associated with severe infections [ 16 ]. Earlier studies conducted on healthy camels in several African and Middle Eastern nations have reported a variable prevalence of S. aureus in nasal carriage, ranging from 6.2% to 89.1% [ 40 , 41 ]. The reasons for this variability are unknown, though it may be due to differences in shared environments or urban lifestyles associated with breeding.…”

“…In both studies, the camels were in traditional farming communities, and the antibiotics may not be widely available or affordable, leading to limited or no use of antibiotics in treating bacterial infections, and thus a low selective pressure is assumed. However, there are few studies available on the general level of antimicrobial use in dromedaries or antimicrobial resistance in bacteria from dromedaries, and the interpretation remains difficult [ 40 , 41 ].…”

Molecular Evolution and Genomic Insights into Community-Acquired Methicillin-Resistant Staphylococcus aureus Sequence Type 88

“…In addition, ST88-t786 and other ST88 clones of t186, t1603, and t729 have frequently been detected in humans, food. or food animals ( 33 , 37 – 39 ). This further suggests potential transmission among the above-mentioned hosts.…”

Methicillin-Resistant Staphylococcus aureus (MRSA) and Other Methicillin-Resistant Staphylococci and Mammaliicoccus (MRNaS) Associated with Animals and Food Products in Arab Countries: A Review

“…Acquisition of methicillin resistance is due to integration of the staphylococcal cassette chromosome mec (SCC mec ), which contains the mecA gene conferring resistance to β-lactams [ 13 ]. In 2011, A divergent mecA homologue, mecA LGA251 , later named mecC , was discovered and located in a novel staphylococcal cassette chromosome mec element, designated SCC mec type-XI [ 14 ]. The mecC was 70% identical to the mec A gene and was initially detected in 15 S. aureus isolates from dairy cattle in England [ 14 ].…”

“…In 2011, A divergent mecA homologue, mecA LGA251 , later named mecC , was discovered and located in a novel staphylococcal cassette chromosome mec element, designated SCC mec type-XI [ 14 ]. The mecC was 70% identical to the mec A gene and was initially detected in 15 S. aureus isolates from dairy cattle in England [ 14 ].…”