Campylobacter lari is a thermotolerant bacterium that sporadically causes gastrointestinal diseases in humans and can be found in wildlife and the environment. C. lari is an understudied species, ...especially in wild birds such as gulls. Gulls are potentially good carriers of pathogens due to their opportunistic behavior and tendency to gather in large flocks. During winter and their breeding period, 1753 gulls were captured, and cloacal swabs were taken to be tested for the presence of C. lari. From isolated bacteria, the DNA was sequenced, and sequence types (ST) were determined. Sixty-four swabs were positive for C. lari, and from those, forty-three different STs were determined, of which thirty-one were newly described. The whole genome was sequenced for 43 random isolates, and the same isolates were tested for antimicrobial susceptibility using the broth microdilution method to compare them to WGS-derived antimicrobial-resistant isolates. All the tested strains were susceptible to erythromycin, gentamicin, and chloramphenicol, and all were resistant to ciprofloxacin. Resistance to ciprofloxacin was attributed to a gyrA_2 T86V mutation. Genes connected to possible beta-lactam resistance (blaOXA genes) were also detected.
This study aimed to assess the presence of thermotolerant Campylobacter spp., as one of the most important foodborne zoonotic pathogens, in three shellfish species: mussels (Mytilus ...galloprovincialis), oysters (Ostrea edulis) and queen scallops (Aequipecten opercularis). The samples were collected from nine locations in the Istrian aquatory, Croatia. Isolation of Campylobacter was done according to standard ISO method, and species were identified using multiplex PCR. Isolates identified as C. jejuni and C. lari were genotyped using multilocus sequence typing (MLST) to determine the potential source of contamination. Among 108 examined samples of bivalve molluscs, mussels dominated and were the only ones found positive for the presence of Campylobacter (25.6%). In total, 19 C. lari and 1 C. jejuni strains were isolated. C. lari isolates found in this study belong to 13 sequence types (STs), and 9 of them are newly described in this paper. Two out of the four previously described C. lari STs that were found in this study were previously found in human stool. The only C. jejuni isolate was found to be sequence type 1268, which belongs to ST-1275 clonal complex that is almost exclusively found in seabirds and can sporadically cause infection in humans. Regarding the obtained results, introducing surveillance of thermotolerant Campylobacter in shellfish in the Republic of Croatia is advised as an improvement for public health safety.
With increasing advances in telemetry technology, prospecting behaviour was identified in many seabirds; mostly in immatures, but also in adults - during pre-breeding and post-breeding periods and ...among failed breeders. However, prospecting has not yet been documented among active breeders. We equipped 17 Common terns Sterna hirundo with GPS-UHF data-loggers and tracked their movements during late incubation and chick rearing in continental Croatia. We monitored the fate of their clutches until chicks left the nest. Birds of both sexes visited other breeding colonies within relatively short distances, while they still had active nests. These results confirm for the first time the presence of prospecting trips during incubation and chick-rearing in active breeders. Such behaviour probably developed because quick and unpredictable changes in their freshwater habitats can cause failure of whole colonies, forcing them to renest at other sites during the same breeding season. Prospecting during the first breeding attempt might shorten the renesting interval, and increase renesting success when multiple breeding sites are available on an easily accessible area. With increasing vulnerability of colony sites due to climate change, studies of scattered colonies are needed to better understand renesting and adult prospecting strategies.
Gulls are a group of seabirds distributed worldwide that are an important reservoir of Salmonella spp. Salmonellosis is the second most commonly reported gastrointestinal infection in humans, and ...understanding the role wild birds have in spreading Salmonella can help to improve the health of humans and domestic animals. The mobility and migration capacity of gulls makes them an interesting group for research given their potential role in spreading pathogens. This paper presents the diversity and prevalence of Salmonella spp. in different gull species caught at a landfill in Zagreb in the winter months over a nine-year period from 2014-2022. In total, 1083 cloacal swabs were sampled from six gull species: Black-headed Gull (Larus ridibundus), Yellow-legged Gull (L. michahellis), Caspian Gull (L. cachinnans), Common Gull (L. canus), Lesser Black-back Gull (L. fuscus) and Herring Gull (L. argentatus). The prevalence of Salmonella was 5.82%, and 16 Salmonella serotypes were identified; S. Typhimurium had the highest prevalence (47.62%) followed by S. Enteritidis (12.69%) and S. Infantis (9.52%). To date, 82 Salmonella serotypes have been isolated in research on gulls in Europe, with S. Typhimurium as the most common, followed by S. Agona and S. Enteritidis. In this study, we found three serotypes not previously reported in gulls, S. Yalding, S. Reading and one with the antigenic formula O:17; H:z10; H:e,n,x,z15 (IIIb).
Galebovi su skupina morskih ptica raširenih diljem svijeta koje su važan rezervoar Salmonella spp. Salmoneloza je druga najčešće prijavljena gastrointestinalna infekcija u ljudi i razumijevanje uloge koju divlje ptice imaju u širenju Salmonella spp. može pomoći u poboljšanju zdravlja ljudi i domaćih životinja. Mobilnost i migracijska sposobnost čini galebove vrlo zanimljivom skupinom za istraživanje zbog njihove potencijalne uloge u širenju patogena. Kroz ovaj rad prikazujemo raznolikost i prevalenciju Salmonella spp. kod nekoliko vrsta galebova ulovljenih na odlagalištu otpada tijekom zime u Zagrebu kroz devetogodišnje razdoblje, 2014.-2022. Ukupno je uzorkovano 1083 obrisaka kloake od šest vrsta galebova: riječni galeb (Larus ridibundus), galeb klaukavac (L. michahellis), pontski galeb (L. cachinnans), burni galeb (L. canus), tamnoleđi galeb (L. fuscus) i srebrnasti galeb (L. argentatus). Ukupna prevalencija Salmonella spp. je 5,82 % sa 16 identificiranih serotipova. S. Typhimurium ima najveću zastupljenost (47,62 %), zatim S. Enteritidis (12,69 %) i S. Infantis (9,52 %). Prema istraživanjima prisutnosti serotipova Salmonella spp. u galebova u Europi izolirana su njih 82, a najčešće dokazani je S. Typhimurium, zatim S. Agona i S. Enteritidis. Tijekom ovog istraživanja identificirana su tri serotipa koja ranije nisu izdvojena iz galebova S. Yalding i S. Reading te jedan iz podvrste S. enterica subsp. diarizonae (IIIb_O:17; H:z10; H:e,n,x,z15).
Campylobacter lari is a thermotolerant bacterium that sporadically causes gastrointestinal diseases in humans and can be found in wildlife and the environment. C. lari is an understudied species, ...especially in wild birds such as gulls. Gulls are potentially good carriers of pathogens due to their opportunistic behavior and tendency to gather in large flocks. During winter and their breeding period, 1753 gulls were captured, and cloacal swabs were taken to be tested for the presence of C. lari. From isolated bacteria, the DNA was sequenced, and sequence types (ST) were determined. Sixty-four swabs were positive for C. lari, and from those, forty-three different STs were determined, of which thirty-one were newly described. The whole genome was sequenced for 43 random isolates, and the same isolates were tested for antimicrobial susceptibility using the broth microdilution method to compare them to WGS-derived antimicrobial-resistant isolates. All the tested strains were susceptible to erythromycin, gentamicin, and chloramphenicol, and all were resistant to ciprofloxacin. Resistance to ciprofloxacin was attributed to a gyrA_2 T86V mutation. Genes connected to possible beta-lactam resistance (blaOXA genes) were also detected.
This study aimed to assess the presence of thermotolerant Campylobacter spp., as one of the most important foodborne zoonotic pathogens, in three shellfish species: mussels (Mytilus ...galloprovincialis), oysters (Ostrea edulis) and queen scallops (Aequipecten opercularis). The samples were collected from nine locations in the Istrian aquatory, Croatia. Isolation of Campylobacter was done according to standard ISO method, and species were identified using multiplex PCR. Isolates identified as C. jejuni and C. lari were genotyped using multilocus sequence typing (MLST) to determine the potential source of contamination. Among 108 examined samples of bivalve molluscs, mussels dominated and were the only ones found positive for the presence of Campylobacter (25.6%). In total, 19 C. lari and 1 C. jejuni strains were isolated. C. lari isolates found in this study belong to 13 sequence types (STs), and 9 of them are newly described in this paper. Two out of the four previously described C. lari STs that were found in this study were previously found in human stool. The only C. jejuni isolate was found to be sequence type 1268, which belongs to ST-1275 clonal complex that is almost exclusively found in seabirds and can sporadically cause infection in humans. Regarding the obtained results, introducing surveillance of thermotolerant Campylobacter in shellfish in the Republic of Croatia is advised as an improvement for public health safety.
Gulls, as migratory wild birds are known that can spread different pathogens over long distances. Aim of this study was to access prevalence of different
Listeria
species in their population fed at ...the Zagreb landfill site. Altogether, 390 gulls of three species were sampled: Yellow-legged Gull,
Larus michahellis
; Black-headed Gull,
L. ridibundus
and Common Gull,
L. canus.
Most prevalent species was
L. innocua
(14.4%), while
L. monocytogenes
was found in 11.3 % of tested samples. The presence of other species was found in a smaller percentage, namely
L. welshimeri
(1.3%),
L. ivanovii
(0.5%) and
L. seeligeri
(0.3%). Serotyping of
L. monocytogenes isolates
was performed using both molecular and conventional methods, and most isolates belonged to serotypes 1/2a and 1/2b. To the best of our knowledge, this study reports the first results of research on the presence of
L. monocytogenes
and other
Listeria
spp. in wild birds in Croatia.
Za galebove, kao divlje ptice selice, je poznato da mogu širiti različite patogene na velike udaljenosti. Cilj ovog istraživanja bio je odrediti prevalenciju različitih vrsta roda
Listeria
u populaciji galebova koja se hrani na zagrebačkom odlagalištu otpada. Sveukupno je pretraženo 390 galebova triju vrsta: galeb klaukavac,
Larus michahellis
; riječni,
L. ridibundus
i burni galeb,
L. canus
. Najzastupljenija vrsta bila je
L. innocua
(14,4 %), dok je
L. monocytogenes
dokazana u 11,3 % ispitanih uzoraka. Prisutnost ostalih vrsta ustanovljena je u manjem postotku, i to
L. welshimeri
(1,3 %),
L. ivanovii
(0,5 %) i
L. seeligeri
(0,3 %). Serotipizacija izolata
L. monocytogenes
provedena je molekularnim i konvencionalnim metodama, a većina izolata pripadala je serotipovima 1/2a i 1/2b. Prema našem saznanju, ova studija donosi prve rezultate istraživanja prisutnosti
L. monocytogenes
i drugih vrsta roda
Listeria
u divljih ptica u Hrvatskoj.
Because of increasing urbanization, some opportunistic birds such as gulls, started to exploit various artificial marine and terrestrial food sources. To better understand urban gull ecology and ...habitat use, a study was done on a yellow-legged gull (Larus michahellis) during the breeding season in Zadar, a coastal city on the Adriatic Sea. Ten adult breeding yellow-legged gulls (five females and five males) were caught on building rooftops during the late incubation period and were fitted with GPS-GSM solar power transmitters. In total, 2377 trip segments (no. GPS points = 19906) were analyzed, with most of them being classified as nest attendance (56.32 %) and foraging movements (37.10 %). Tracking data showed that the gulls mostly use marine and urban areas, agricultural lands, a dump site, and grasslands. Females were more active while foraging, with a longer duration and trip segment length, travelling further away from the breeding colony, while males tended to rest more than females. Both males and females exploit various habitats for foraging and resting, however females used agricultural lands significantly more than males. Even though gulls are generalists, some individuals showed a preference for certain habitats. After calculating the proportional similarity index, individuals showed high specialization for a certain habitat.
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