The bacterial flora of clinically healthy reptiles can be extremely diverse. The objectives of this study were to determine the bacterial flora in oral swabs from two different species of water turtles and to study growth characteristics and antibiotic resistance of these isolates. Oral swabs were collected from 20 clinically healthy common musk turtles (Sternotherus odoratus) and 20 West African mud turtles (Pelusios castaneus) and incubated at two different temperatures (25 and 37°C; 77.0 and 98.6°F) on various agar plates. All isolates were tested for susceptibility to a panel of antibiotics. A total of 66 distinct bacterial types were collected, 63 (95.45%, 95% confidence interval [CI]: 90–100) of which were Gram negative and 3 (4.55%, 95% CI: 0–27) of which were Gram positive. The most commonly isolated genera were Citrobacter spp. (in 97.5% of the animals tested, 95% CI: 93–100), Aeromonas spp. (in 92.5% of the animals tested, 95% CI: 84–100), Chryseobacterium spp. (in 80% of the animals tested, 95% CI: 68–92), and Salmonella spp. (in 80% of the animals tested, 95% CI: 68–92). The most commonly isolated bacterium was Aeromonas hydrophila (77.5%, 95% CI: 65–90). The oral bacterial flora of all of the examined animals consisted of a wide mixture of bacteria, many of which were potential pathogens. The combination of bacteria detected differed between individual animals. Incubation at 25 and 37°C led to the detection of distinct populations of bacteria. The resistance testing showed that many of the bacteria detected were resistant to a wide range of antibiotics.

The oral flora of most clinically healthy reptiles consists of a broad, quantitatively balanced mixture of various species and genera of bacteria (Straub, 2002), often including organisms that are potentially pathogenic for reptiles (Santoro et al., 2006). When interpreting laboratory findings, it is always important to consider the animal's clinical presentation, because in many cases even animals with remarkable laboratory results will appear clinically healthy (Straub, 2002). The extreme variability of the normal flora also makes interpretation difficult, especially because bacteria detected can vary not only between different species, but also between individuals of a single species even when they are kept together. The bacterial flora can also change quickly over time. In addition to species, sex, environment, nutrition, climatic conditions, age, and time of year can also influence the bacterial flora (Carter and Cole, 1990). Brumation in chelonians can also cause severe changes in the normal bacterial flora (Straub, 2002). This variability makes a general determination of what the normal bacterial flora for a particular species or group challenging to impossible, especially because variation can also be detected between individuals kept together under identical conditions (Carter and Cole, 1990; Mörk, 1997).

The majority of sources on the bacterial flora of reptiles show that potentially pathogenic bacteria are a common component of the normal flora (Paré et al., 2006). In particular, Gram-negative bacteria are often considered potential pathogens and make up a large portion of the bacteria detected in healthy reptiles.

There are varying opinions on the optimal incubation temperature for reptile samples, ranging from a standard 37°C (98.6°F) to various lower temperatures. Cooper (2000) suggests a standard 37°C, whereas Hoffmann et al. (2008) state that such high temperatures can lead to false results. Needham (1981) advocates routine incubation at 37°C, but states that additional incubation at 24°C (75.2°F) may be appropriate for reptiles with a preferred optimal temperature zone of less than 30°C (86.0°F). There is no standard available for the routine incubation of reptile samples.

Antibiotic resistance is always an important topic in various areas of veterinary medicine as well as in human medicine and environmental hygiene. Minimal literature is available on the resistance profiles of bacteria found in clinically healthy reptiles. Studies on aquatic reptiles and amphibians in Turkey showed that a relatively large number of isolates were resistant to multiple antibiotics (Hacioglu and Tosunoglu, 2014). Comparisons of antibiotic resistance in bacteria isolated from a wild and a zoo population of red-eared sliders (Trachemys scripta elegans) showed no clear differences between the groups, but multiple drug resistance was documented in both groups (Liu et al., 2013).

The aim of this study was to determine the bacterial flora of two aquatic chelonian species, common musk turtles (Sternotherus odoratus) and West African mud turtles (Pelusios castaneus). Incubation temperatures of 25°C (77.0°F) and 37°C were compared and the isolated bacteria were tested for susceptibility to a standard panel of antibiotics.

Turtles: The samples for this study were collected from 40 turtles from a German reptile dealer. Oral swabs were collected from 20 common musk turtles and 20 West African mud turtles. The sampled turtles were kept in larger groups together with other turtles of the same species. All turtles were fed turtle pellets with the addition of dried fly larvae. Frozen thawed mosquito larvae were fed to all groups once a week. The sampling was carried out during the course of quarantine testing of the animals prior to sale. Not all animals in the groups were tested. The mud turtles originated from a breeding farm in Togo, West Africa, whereas the musk turtles had been imported from a medium-sized farm in North America.

The approximately 3-month-old mud turtles weighed 4–5 g each and had a carapace length of 2–3 cm. Five animals were chosen randomly from four aquariums containing 25 animals each. Every aquarium was 80 × 60 cm with a water depth of 5 cm. The 20 musk turtles had a carapace length of between 7 and 11 cm, weighed between 120 and 150 g, and were approximately 2 yr old. Four animals were randomly chosen from each of five different aquariums. These containers were 120 × 90 cm large with a water depth of approximately 30 cm. Each had been inhabited by 30 animals for the 4 wk previous to sampling. Each aquarium had a separate water intake and water was filtered through separate filters and ultraviolet sterilizers. Water was not mixed between the aquariums. The musk and mud turtles were provided water temperatures of 22–23°C (71.6–73.4°F) and 23–24°C (73.4–75.2°F), respectively. The nightly temperature reduction was approximately 2°C. The air temperature in the containers averaged between 24–26°C (75.2–78.8°F); the warmest spot in the aquarium was about 30°C (86.0°F). The husbandry conditions for the turtles from all nine containers did not differ significantly from one another. The temperature was adjusted with the use of an industrial stainless steel heating element with a Hamburg mat cleaner and was controlled with a thermostat.

All of the animals used in the study had been free of clinical disease for at least 3 months prior to sampling and received no medication during this time. The sampling was carried out by a veterinarian as part of a health screen and was done following a short physical examination. All animals were considered clinically healthy at the time of sampling.

Sample collection, transport, and isolation of bacteria: Sample collection was carried out with cotton-tipped swabs of the oral cavity and pharynx. Swabs were then placed in sodium thioglycolate transport medium and transported to the laboratory for testing. After arrival at the laboratory, up to 20 h after swabbing, the samples were inoculated onto agar plates with the use of a three-sector T-streak pattern. Two Columbia blood agar plates with 5% sheep blood (COS), endo, HAEM, MacConkey, and xylose lysine desoxycholate agar plates were prepared from each sample. One of each was incubated aerobically at 37°C +/− 2°C and one at 25 °C +/− 2°C for 24 h.

In addition, an enrichment culture was carried out with the remaining material in the thioglycolate broth at 37°C +/− 2°C for 24 h. After the incubation period, the enriched material was also streaked onto two COS and two endo agar plates. These were then incubated at 25°C +/−2 °C and 37 °C +/−2°C for 24 h.

The agar plates were then visually evaluated for morphologically distinct defined cultures. Pure cultures were obtained by subculturing individual colonies onto COS and endo agar. If necessary, cultures that could not be separated or that swarmed were again streaked onto Hektoen agar. Incubation was carried out at the same temperature as for the original plates.

The specific properties of the chosen enrichment and differentiation plates as well as simple biochemical parameters such as oxidase or catalase were used for initial differentiation of isolates and to test the plausibility of the results of the MALDI-TOF (matrix-assisted-laser-desorption-ionization time-of-flight mass spectrometer) testing.

Identification of bacteria: Pure cultures were identified with a MALDI-TOF. A small amount of the bacterial culture (104 plaque forming units [PFU]) from the COS or endo agar medium was transferred onto a metal plate (target) and covered with 0.5 μl of an organic crystallization matrix (a-Cyano). Formic acid (0.8 μl) was used with slimy cultures instead of a-Cyano. The targets were then placed in a mass spectrometer (MALDI-TOF Axima Assurance, Shimadzu, Bio-Merieux, Nürtingen, Germany), which ionized the proteins in the sample. The resulting bacteria specific mass spectrum, in the range of 2–20 kDa, was then used to identify the isolated bacteria with the help of a reference data base (Geier-Dömling et al., 2009). If no result or inconclusive results (<70% probability) were obtained, the bacteria was again grown on COS and endo agar and retested with MALDI-TOF. After identification, the results were confirmed by biochemical methods such as catalase, oxidase, and Gram staining.

Bacteria that could still not be identified or were inconclusive following the second round of testing with MALDI-TOF were further tested with API (Analytischer-Profil-Index, BioMereux, Nürtingen, Germany). First, an oxidase test was carried out. Oxidase-positive isolates were further tested with the API® 20 NE System, and oxidase-negative isolates were tested with the rapid ID 32 E System. Testing was carried out according to the manufacturer's instructions. For the catalase test, a loop full of the bacterial colony was placed on a glass slide and 3% hydrogen peroxide was added. The oxidase test was carried out with oxidase paper strips for lactose negative colonies. All individual colonies were stained with a Gram stain, and the results were compared to those obtained with MALDI-TOF and biochemical methods and tested for plausibility.

Antibiograms: For the antibiograms, a part of the relatively young colony was added to 3 ml sterile 0.9% saline solution. After homogenization with a vortex, a densitometer was used and the density was adjusted to a McFarland Standard of 0.5. The sample was then diluted by a microdilution method and, together with the culture medium, pipetted into precast MICRONAUT resistance plates. The following antibiotics were used in the resistance testing: cephalexin, cefquinom, cefoperazin, cefovecin, difloxacin, enrofloxacin, pradofloxacin, marboflocaxin, ibafloxacin, penicillin G, oxacalline, ampicillin, amoxicillin with the β-lactamase inhibitor clavulanic acid, gentamicin, tobramycin, streptomycin, spectinomycin, neomycin, tetracycline, doxycycline, chloramphenicol, erythromycin, spiramycin, clindamycin, lincomycin, cotrimoxazol, nitrofurantoin, rifampicin, colistin, and fusidinic acid. Evaluation of the inhibitory effects was carried out after 24 h incubation at 37°C with the use of a photometer. The values were tested for plausibility and validated. Isolates were either sensitive (S), intermediate (I), or resistant (R) to the tested antibiotics.

Statistical analysis: The 95% binomial confidence intervals (CI) were calculated for each proportion. The distribution of continuous data was evaluated with the use of the Shapiro-Wilk test. Because data were normally distributed, an independent-samples t-test was used to compare differences in isolate numbers between turtle species/aquariums. SPSS 22.0 (IBM Statistics, Armonk, NY) was used to analyze the data. A P < 0.05 was used to determine statistical significance.

Oral bacterial flora: A total of 66 different bacteria types were isolated from the 40 turtles examined. The bacterial species and the frequency with which they were detected are listed in Table 1. Sixteen of the bacteria could be identified to the genus level, 50 to the species level. The most commonly isolated genera were Citrobacter (97.5%, 95% CI: 93–100) and Aeromonas (92.5%, 95% CI: 84–100). Chryseobacterium and Salmonella were each detected in 80% (95% CI: 68–92) of the animals.

Table 1.

Isolated bacteria and their frequency of occurrence in the 40 turtles examined.

Isolated bacteria and their frequency of occurrence in the 40 turtles examined.
Isolated bacteria and their frequency of occurrence in the 40 turtles examined.
Table 1.

Continued.

Continued.
Continued.

Members of 17 different bacterial families were found in the turtles. Two members each were from the families Alcaligenaceae, Bacillaceae, Campylobacteraceae, Pasteurellaceae, Shewanellaceae, Sphingobacteriaceae, Spirillaceae, Staphylococcaceae, and Streptococcaceae. Two isolates belonged to the families Brucellaceae and Myroidaceae. Three isolates belonged to each of the families Comamonadaceae and Xanthomonadaceae. Four, 8, and 10 isolates each belonged to the families Flavobacteriaceae, Moraxellaceae, and Pseudomonadaceae, respectively. The family to which the largest number of isolates belonged was Enterobacteriaceae, with 25 isolates. A mixed flora with 8–19 different bacteria belonging to at least three different families was detected in each of the 40 turtles.

Comparison of the two turtle species: A total of 39.4% of the bacterial species detected were found in both turtle species. Of the total bacterial spectrum, 19.7% was found only in the mud turtles, and 40.9% was found only in the musk turtles. The flora found in both included the following 26 genera and species: Citrobacter spp., Aeromonas spp., Chryseobacterium spp., Salmonella spp., Aeromonas hydrophila, Proteus spp., Serratia marcescens, Pseudomonas spp., Acinetobacter johnsonii, Acinetobacter spp., Pseudomonas aeruginosa, Pseudomonas putida, Enterobacter spp., Shewanella putrefaciens, Aeromonas punctata, Citrobacter freundii, Comamonas testosteroni, Stenotrophomonas maltophilia, Enterobacter cloacae, Proteus mirabilis, Klebsiella oxytoca, Klebsiella pneumoniae, Elizabethkingia meningoseptica, Acinetobacter junii, Providencia rettgeri, and Alcaligenes faecalis. Each of the bacteria found only in one of the two species was found in less than 40% of the animals.

Comparison of different aquariums: The following bacteria were found in animals in all of the aquariums tested: Acinetobacter spp., Aeromonas hydrophila, Aeromonas spp., Chryseobacterium spp., Citrobacter spp., Proteus spp., Pseudomonas spp., Salmonella spp., and Serratia marcescens.

Enterobacter spp. and Pseudomonas aeruginosa were also found in all of the musk turtles tested, and all of the mud turtles also had Comamonas testosteroni. There were significantly (t = 2.84, P = 0.03) more isolates found in aquariums with musk turtles (mean: 26.5, SD: 1.3, min–max: 25–28) than in the aquariums with mud turtles (mean: 21.4, SD: 3.3, min–max: 17–26).

Comparison of the isolation temperatures: A direct comparison of the bacteria isolated at 25 and 37°C showed clear differences between the two temperatures. The following bacteria were only isolated at 37°C: Acinetobacter iwoffii, Providencia rettgeri, Chryseobacterium gleum, Plesiomonas shigelloides, Aeromonas sobria, Pseudomonas alcaligenes, Myroides spp., Acinetobacter haemophilus, Brevundimonas vesicularis, Alcaligenes faecalis, Staphylococcus epidermidis, Actinobacillus lignieresi, Proteus penneri, Sphingobacterium multivorum, Pseudoxanthomonas japonensis, Edwardsiella spp., Bacillus cereus, and Yokenella regensburgei, and the following were only isolated at 25°C: Campylobacter jejuni, Myroides odoratissimus, Lactococcus garvieae, Ochrobacter anthropi, Raoultella spp., Chryseobacterium indologenes, Vibrio spp., Proteus mirabilis, Klebsiella spp., Kluyvera cryocrescens, Aeromonas veronii, Pantoea spp., Pantoea spp. 3, Proteus vulgaris, Citrobacter braakii, Haemophilus influenzae, Moraxella lacunata, Moraxella osloensis, and Acinetobacter ursingii. All of the isolates found only at one of the two temperatures were only found in up to 7.5% of the samples (i.e., were found in three or less of the samples).

A number of bacteria were found more commonly (>50%) at one of the incubation temperatures. The following were isolated more commonly at 37°C: Enterobacter spp. (80%), Acinetobacter spp., Aeromonas punctata, Klebsiella oxytoca, Citrobacter freundii, Stenotrophomonas maltophilia (75%), Pseudomonas aeruginosa (73%), Pseudomonas spp. (69%), Enterobacter aerogenes, Shewanella putrefaciens, Klebsiella pneumoniae, Acinetobacter junii (67%), and Aeromonas hydrophilia (60%). These bacteria were found in 10–57.5% of cases. The following bacteria were found more commonly at 25°C: Delftia acidovorans (80%), Comamonas aquatica (75%), Aeromonas spp., Salmonella spp. (70%), Proteus spp., Serratia marcescens, Elizabethkingia meningoseptica (67%), Acinetobacter johnsonii (62%), and Raoultella ornithinolytica (57%).

Antibiograms: The results of the antibiograms are shown in Table 2 and in Figure 1. All of the isolates were sensitive to pradofloxacin. Over 50% were sensitive to marbofloxacin, enrofloxacin, ibafloxacin, gentamicin, neomycin, and doxycycline. Members of all 15 bacterial families tested were resistant to colistin and lincomycin. Resistances to the following antibiotics were also detected: spectinomycin (93%); cefquinom, penicillin G, and amoxicillin/clavunanic acid (87%); clindamycin (80%); oxacillin, ampicillin, and nitrofurantoin (73%); and cephalexin, tobramycin, and spiramycin (67%). No antibiograms could be determined for members of the Pasteurellaceae and Staphylococcaceae because of slow growth. It should be noted that many of the bacteria isolated in this study have intrinsic resistance to some of the antibiotics tested (e.g., Gram-negative bacteria lack sensitivity to β-lactam antibiotics).

Figure 1.

Number of resistant and sensitive isolates according to antibiotic. R = resistant, I = intermediate, S = sensitive. y axis = number of isolates in percent.

Figure 1.

Number of resistant and sensitive isolates according to antibiotic. R = resistant, I = intermediate, S = sensitive. y axis = number of isolates in percent.

Close modal
Table 2.

Overview of the bacterial families found in the turtles tested with the most effective antibiotics (effectivity in %).

Overview of the bacterial families found in the turtles tested with the most effective antibiotics (effectivity in %).
Overview of the bacterial families found in the turtles tested with the most effective antibiotics (effectivity in %).

Each of the clinically healthy animals tested had a wide range of mixed bacteria consisting of at least eight different bacterial species or genera in their oral cavity. In no case was there a shift to a single predominant bacterial organism. Straub (2002) hypothesized that a shift to a single or very low number of bacterial isolates from a single animal is a sign of a possible problem, and that a diverse mixed flora is to be expected in clinically healthy animals.

The species diversity in the oral cavity of clinically healthy turtles is very wide and can differ greatly between individuals (Mörk, 1997). For this reason, it is not possible to determine a qualitative and quantitative description of a standard normal flora of turtles. Because many of the isolates could only be identified to the generic level by MALDI-TOF, it is likely that the range of bacteria in the turtles tested was even wider than reported here, because each identified genus might include a number of different species. Additional testing would be necessary to characterize all of the isolates obtained in this study fully. Future studies with reptilian isolates and MALDI-TOF, supplemented with partial genome sequencing, would be helpful in establishing standard methods for the identification and characterization of bacterial isolates from these animals.

The majority of bacteria found in this study have been previously described as part of the normal bacterial flora of reptiles, including bacteria from the genera Acinetobacter, Actinobacillus, Aeromonas, Alcaligenes, Bacillus, Citrobacter, Elizabethkingia, Enterobacter, Escherichia, Haemophilus, Klebsiella, Kluyvera, Moraxella, Proteus, Pseudomonas, Salmonella, Serratia, Staphylococcus, and Vibrio (Mörk, 1997; Straub, 2002; Santoro et al., 2006; Jacobson, 2007). The results of this study also demonstrate that a large portion of the normal flora of these turtles is comprised of bacteria that are potentially pathogenic to reptiles and humans. This has also been described in previous studies (Mitchell and Shane, 2001; Straub, 2002; Santoro et al., 2006; Paré et al., 2006; Liu et al., 2013), and was therefore expected. According to Jacobson (2007), a number of bacteria in the genera Pseudomonas, Aeromonas, Citrobacter, Serratia, Elizabethkingia, and Vibrio are potentially pathogenic for reptiles. Members of the genera Providencia, Klebsiella, Edwardsiella, Enterobacter, Proteus, Salmonella, Acinetobacter, and Escherichia also have pathogenic potential (Paré et al., 2006). Genera found to belong to the normal flora in the present study that have not been described previously in this role include Campylobacter, Chryseobacterium, Comamonas, Edwardsiella, Lactococcus, Myroides, Ochrobacter, Pantoea, Plesiomonas, Pseudoxanthomonas, Raoultella, Sphingobacterium, and Yokenella.

Only three (4.5%) of the 66 isolated bacteria were Gram positive. This result shows that Gram-negative bacteria can clearly dominate, even in clinically healthy animals. Previous studies have also revealed this predominance of Gram-negative bacteria in clinically healthy chelonians, although not quite as strongly (Mitchell and McAvoy, 1990; Mörk, 1997; Straub, 2002; Liu et al., 2013). Gram-negative bacteria were the only isolates found in 92.5% of the turtles tested.

Bacteria of the genus Citrobacter were found most commonly in the animals studied. Bacteria of this genus, particularly C. freundii, which was isolated from six animals in this study, have been described as both commensals (Mörk, 1997) and potential pathogens (Paré et al., 2006). Citrobacter freundii has been associated with septicemic cutaneous ulcerative disease (SCUD) in aquatic turtles (Jacobson, 2007).

The second most commonly detected genus was Aeromonas, which has frequently been described in the oral cavities of reptiles (Mörk, 1997; Straub, 2002; Santoro et al., 2006; Jacobson, 2007) and is considered a normal part of the flora in small numbers (Paré et al., 2006). However, members of this genus, particularly the bacterium Aeromonas hydrophila, are considered to have a high pathogenic potential. According to Paré et al. (2006), A. hydrophila is associated with sepsis, and skin and mucous membrane lesions, and is commonly found in aquatic turtles (Jacobson, 2007). Aeromonas hydrophila is also frequently found in water and can replicate quickly at temperatures above 22°C.

The genera Salmonella and Campylobacter are important zoonotic agents. They are found in a wide range of wild and domestic animals. In reptiles, Salmonella are often a part of the normal bacterial flora. These bacteria are particularly dangerous for infants, small children, and immune-compromised individuals, and are a regular cause of human infections. Salmonella are routinely isolated from both wild and captive reptiles (Liu et al., 2013; Marin et al., 2013). Eighty percent of the animals tested in this study had Salmonella in their oral cavity. Positive animals were found in each of the aquariums tested and from both species tested. This highlights the importance of appropriate hygienic measures when one is keeping aquatic turtles. Campylobacter jejuni was found in a single animal in this study. Earlier studies were unable to detect Campylobacter spp. in wild turtles (Marin et al., 2013). This bacterium does not appear to belong to the normal flora of most turtles. It is unknown how and why this single animal became a carrier of Campylobacter jejuni.

There are a number of possible reasons for greater variety of bacteria found in the musk turtles compared to the mud turtles. These animals were obtained from a very large operation where they were kept with a large number of conspecifics. The introduction of wild animals in this operation cannot be ruled out. It is therefore possible that these animals had greater contact with a wider range of bacteria prior to their introduction to the facility at which they were tested. The feeding of the musk turtles also differed some-what from that of the mud turtles. The musk turtles were fed a slightly higher amount of dried fly larvae than the mud turtles, which could influence the amount of bacteria to which they were exposed. Because a very wide range of factors influence the normal bacterial flora, it is not surprising that differences were found both between the two species and individual turtles.

The choice of incubation temperature for bacterial culture of samples from reptiles has been controversially discussed in the literature (Cooper, 2000) and is carried out differently in different laboratories. A direct comparison of the two incubation temperatures chosen (25°C and 37°C) was carried out in order to develop a basis for standardizing incubation temperatures for these species. Bacteria isolated at 25°C were compared to those isolated at 37°C. The morphology and growth of the bacteria on the same types of agar were different at the different temperatures in some cases. A number of bacteria were only isolated at one of the two temperatures. Eighteen isolates were only isolated at 37°C and 19 only at 25°C, so that the numbers at each temperature were about balanced and over a quarter of the isolates were only found at one of the two temperatures. However, none of these were found in more than 10% of the 40 samples tested. A number of isolates were found with higher frequency at one of the two temperatures: 13 at 37°C and 9 at 25°C. For this reason it is recommended that bacterial samples from aquatic turtles be incubated at both 25 and 37°C. The results of this study also indicate that detection of the genera Pseudomonas, Aeromonas, Citrobacter, Serratia, Elizabethkingia, Vibrio, Providencia, Klebsiella, Proteus, Salmonella, Acinetobacter, Alcaligenes, Bacillus, and Enterobacter, all of which are considered potentially pathogenic for reptiles, can only be guaranteed if incubation is carried out at both temperatures.

The most effective antibiotic according to the antibiograms was the gyrase inhibitor pradofloxacin, which was effective against all of the bacteria tested. In the case of clinical disease, it is important to determine which bacteria might be responsible for the clinical signs and to treat these specifically following an antibiogram. It is also important to note that the results of an in vitro antibiogram may differ from the effects in vivo and that many factors, including health status, species, weight, and metabolism, influence these effects.

The antibiograms also showed that a number of the isolated bacteria were resistant to a wide range of different antibiotics. These included potential pathogens that were commonly isolated, such as members of the genera Pseudomonas, Aeromonas, and Acinetobacter (Jacobson, 2007). In order to avoid the development of additional resistance in future, it is important to carry out an antibiogram prior to treatment of reptiles. For that purpose it might also be helpful to include additional antibiotics commonly used in reptile practice in future studies.

The bacterial analysis of oral swabs from healthy aquatic mud and musk turtles shows that their normal flora consists of a broad mixed flora of mostly Gram-negative bacteria. The interpretation of bacterial findings is complicated by the variability of the normal flora and the presence of potential pathogens in clinically healthy animals.

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